Gels doi: 10.3390/gels12111044

Authors: Tianhui Liu Changshun Lv Wen Li Lin Jiang Qi Qi Changjie Bao Wei Liu Yuchen Xing Meiyan Sun Hongxun Fu

Lysozyme (LZM) is a naturally occurring antimicrobial protein. LZM can hydrolyze peptidoglycans in bacterial cell walls, and can also exert non-enzymatic antibacterial effects by interacting with bacterial membranes. Beyond its intrinsic biological activity, LZM can participate in hydrogel network formation or serve as a precursor for amyloid fibril assembly, making it both a bioactive component and a structural building block. This review summarizes the preparation strategies and multifunctional applications of LZM-based hydrogels. These strategies include physical and supramolecular assembly, amyloid fibril formation, covalent crosslinking, and hybrid network construction. Depending on network design, these strategies can impart properties such as injectability, self-healing, tissue adhesion, and stimuli responsiveness. LZM hydrogels have shown potential for infection control and wound healing through antibacterial activity, biofilm inhibition, and support for tissue repair. As a drug delivery carrier, LZM hydrogels have been investigated for the delivery of antibiotics, growth factors, and anticancer drugs. LZM hydrogels have also been explored in bone, corneal, and cardiac tissue engineering. In addition, LZM hydrogels incorporating molecular imprinting or functionalized components have shown potential applications in biosensing and food preservation. However, challenges remain in maintaining enzymatic activity, evaluating long-term biological safety, and ensuring reproducible material preparation. Further clarification of structure–function relationships and standardized performance evaluation will be important for the practical development of LZM hydrogels.

Gels doi: 10.3390/gels12111045

Authors: Yizhuo Li Xiangze Li Siqi Zhang Zhaohui Liu Anlin Shao Hani S. Mitri

Cemented paste backfill (CPB) provides a pathway for utilizing metallurgical solid wastes, in which blended precursor constituents hydrate and develop strength-bearing gel products within the hardened backfill. Screening multi-component formulations is experimentally intensive because each candidate requires preparation, curing, and multi-age strength testing. The primary contribution of this study is a data-driven virtual experimental environment that integrates multi-age UCS surrogates, constrained chemistry-to-recipe mapping, cost and feasibility evaluation, and Markovian campaign updates. This environment is used to investigate sequential experimental-design strategies for balancing strength, cost, and recipe feasibility. Forty-eight measured mixtures comprising five gel-forming precursor constituents, four process variables, and 3-, 7-, and 28-day uniaxial compressive strength (UCS) were used to construct age-specific surrogate models. A chemistry-space representation based on six major oxides was introduced, and candidate chemistries were mapped to executable formulations through constrained optimization. Sequential formulation design was cast as a finite-horizon Markov decision process and investigated using reinforcement learning (RL) and query-by-committee active learning (AL). Each campaign comprised 50 surrogate-generated virtual queries; no additional specimens were prepared for these campaign evaluations. Under normal supply, LSTM-based RL obtained the highest five-seed mean dimensionless strength-cost score (0.1895), equivalent to 84.8% of the optimistic PSO reference; the best AL configuration reached 0.1753. A supplementary 50-seed virtual comparison yielded 0.1818 versus 0.1729 (paired t-test, p = 0.0064). AL and RL were statistically unresolved when steel slag was unavailable, whereas AL retained a higher fraction of the case-specific PSO reference after the EAF reduction-slag price doubled. Randomized feed-chemistry simulations further showed that the workflow can re-project target chemistries and identify feasible candidates within the domain represented by the surrogate data. The resulting computational environment supports efficient screening of sequential design strategies and prioritization of promising precursor recipes for subsequent laboratory preparation, strength verification, and hydrate-gel characterization.

Gels doi: 10.3390/gels12111043

Authors: Alexandra Nicolae-Maranciuc Daniel Marconi Lucian Barbu-Tudoran Athanasios Tiliakos Dan Chicea

Silver nanoparticles are widely incorporated into polymer dressings, but the effect of the nanoparticle synthesis conditions on the final material is rarely compared within one polymer matrix. Here, citrate-stabilized Ag NPs were prepared by NaBH4 reduction using two reductant volumes (400 and 1000 µL) and incorporated into the same chitosan (CH)/poly(vinyl alcohol) (PVA) matrix cast with citric acid. UV-Vis, DLS, STEM, AFM and XRD showed face-centered cubic Ag NPs with mean diameters of 27 ± 5 nm (1000 µL) and 38 ± 6 nm (400 µL) by STEM, with the same trend by DLS and AFM. Their antibacterial effect was assessed using agar diffusion tests. In agar diffusion tests, the smaller Ag NPs gave larger inhibition zones against Escherichia coli and Staphylococcus aureus The corresponding hydrogel with smaller Ag NPs confirmed the antibacterial tests performed on nanoparticles and gave larger inhibition zones for both bacterial strains. The integration of Ag NPs in hydrogels was confirmed by SEM-EDX mapping, while their integrity was assessed using swelling tests and Ag NPs release tests. In PBS, all films, including the Ag-free control, remained intact for 48 h, with the highest swelling ratio for CH/PVA/Ag-NaBH4 1000.After 24 h in PBS at 37 °C, about 75% (CH/PVA/Ag-NaBH4 1000) and 53% (CH/PVA/Ag-NaBH4 400) of the incorporated Ag NPs were released. The CH/PVA/Ag-NaBH4 1000 formulation is therefore the more promising candidate to be considered a favorable antibacterial polymeric dressing.

Gels doi: 10.3390/gels12111042

Authors: Jianbin Wang Jiakai Wu Guilin Jiang Qing Li Lijia Liu Chunhong Zhang

High-power-density modern electronics demand thermally conductive gel-based thermal interface materials (TIMs) that integrate high thermal conductivity, excellent processability, and long-term reliability, yet conventional monoalkyl silanes fail to balance these requirements in high-filler-loading systems. In this work, a series of novel bridged dialkyl silanes were designed and synthesized to modify fillers for fabricating high-performance TIMs. Systematic investigations demonstrate that BD-C12, bearing two 12-carbon alkyl chains, outperforms all other silanes studied. At a filler loading of 92.5 wt%, the BD-C12-modified TIM strikes an optimal balance between thermal conductivity (7.1 W m−1 K−1) and processability (viscosity of 260 Pa s), while maintaining satisfactory mechanical properties with a tensile strength of 0.08 MPa and an elongation at break of 102%. Compared with traditional monoalkyl counterparts, the dual-site anchoring of BD-C12 constructs stronger filler-matrix bonding that resists moisture erosion and prevents interfacial debonding during long-term aging, as confirmed by simulated packaging reliability tests. Notably, over 96% of initial thermal conductivity is retained after 288 h of uHAST aging. This work provides a promising silane design strategy for developing a high-performance, high-reliability thermally conductive gel with great application potential in advanced electronic heat dissipation.

Gels doi: 10.3390/gels12111041

Authors: Xin Fu Shabnam Arash Xiaoqing Du Shahnaz Rahimi Yangwei Deng Michael J. Lush Jie Rong Eleanor Ransdell-Green Artem Marchenko Mengmeng Liu Detrek Y. Hansen Han-Jun Wang Edward V. Fehringer Dong Wang

Opioids are potent analgesic agents, frequently being used to manage severe pain associated with musculoskeletal (MSK) trauma. The adverse effects of systemic opioids, such as respiratory depression, development of dependency and tolerance have impeded clinical opioid utility. To overcome these limitations, we have developed N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-based thermoresponsive polymeric prodrugs (ProGel-HMP) of hydromorphone (HMP) as a novel peripherally restricted analgesic agent for local management of MSK pain. In the present study, ProGel-HMP formulations were synthesized and characterized for their physicochemical properties. The localized retention and tissue biodistribution were assessed using near-infrared (NIR) optical imaging in a mouse model of closed femoral fracture. Analgesic efficacy was evaluated through static weight-bearing (incapacitance test) and dynamic gait analysis (CatWalk XT) over three weeks post-ProGel-HMP administration. Potential systemic analgesia was assessed via tail-flick latency. The risk of respiratory depression was evaluated using whole-body plethysmography in rats. Quantitative micro-computed tomography (micro-CT) was performed at 6 weeks post-ProGel-HMP treatment to screen for any potential impacts on the fracture healing process. NIR optical imaging confirmed that local intra-callus injection of ProGel-HMP resulted in its sustained retention at the fracture site for at least 14 days. A single local administration of ProGel-HMP provided sustained pain relief, maintaining balanced static weight distribution and improved dynamic gait parameters for up to 21 days post-fracture, whereas dose-equivalent free HMP lost efficacy within 2 days. Tail-flick testing demonstrated substantially reduced systemic antinociceptive activity following ProGel-HMP administration compared with dose-equivalent free HMP. Whole body plethysmography revealed no significant impairment in respiratory rate, tidal volume, or minute ventilation. Quantitative micro-CT analysis verified that ProGel-HMP treatment did not compromise the fracture healing process, with similar callus morphology, bone mineral density, and microstructural parameters when compared to controls. In conclusion, intra-callus administration of thermoresponsive ProGel-HMP provides potent and sustained local analgesia in a closed femoral fracture mouse model. These findings support ProGel-HMP’s potential as a promising peripherally restricted analgesia for pain management in orthopaedic trauma.

Gels doi: 10.3390/gels12111040

Authors: Tiantian Zhang Yingying Jia Bo Huang Yuanjing Zheng Jianfeng Tan

Lacquer art on wood uses lacquer layers for color, gloss, and carved patterns, with optional protective topcoats over completed decoration; production and protection balance application and leveling, processing, and the stability of wood and decorative layers. Studies examine network formation in resins or gels and the performance of free films and coated wood, but links to processing and use of complete lacquer-art assemblies remain incomplete. Some liquid-containing gels release protective oil during application; curing networks progressively restrict flow, whereas preformed gel-derived particles locally affect film properties. This review compares natural lacquer, urushiol-derived resins, and related wood coatings to examine how matrix network formation, inorganic components, microcapsules, wood–coating interfaces, and outer surfaces affect leveling, gloss, scratch repair, and moisture protection. Premature loss of flow can hinder leveling; in the formulations studied, increased silica sol reduced gloss, while higher tung-oil microcapsule loading increased scratch narrowing but lowered initial hardness and adhesion; in a Coromandel lacquer study, the lacquer reduced moisture-induced wood deformation while the ground remained weak. Curing schedules and component loadings should match the intended surface and processing; protection assessment should address the ground and interlayer bonding and test whether appearance and water resistance persist together after exposure and maintenance.

Gels doi: 10.3390/gels12111039

Authors: Zhiheng Nie Fusheng Niu Jinxia Zhang Zeen Yang Yintong Zhang Keqing Li Zehong Cheng Siqi Zhang

Steel slag (SS) and iron ore tailings (IOTs) can reduce cement demand in mine backfill, but strength gains may come with greater flow resistance and processing burdens. This review examines how material functions, gel evolution and interfaces connect treatment to engineering performance, and synthesizes criteria for selecting SS–IOT formulations. SS supplies calcium-bearing hydraulic phases and alkalinity, whereas IOT contributes packing, hydrate-bearing surfaces and mineralogy-dependent chemical participation. Silicate gels develop with ettringite and carbonate-bearing hydrates, influencing interfacial bonding and stiffness. Comparison across studies shows that activator response depends on the complete binder formulation and that strength can increase despite bulk pore coarsening. A gentler post-peak decline can accompany lower peak load capacity. Increasing yield stress and decreasing plastic viscosity exert competing effects on pipeline pressure loss. In the reviewed pre-carbonation series, most estimated carbon savings came from composite-binder substitution, with a smaller increment from treating the slag. These findings support treatment selection based on required strength, deformation capacity, transportability and stability, with process burdens and costs assessed for formulations that meet those requirements. Laboratory, pipeline-loop and field evidence inform the successive measurements needed for scale-up.

Gels doi: 10.3390/gels12111038

Authors: Shengxiang Chen Qinglang Han Hengxiang Liu Zishuai Chen Ziwei Liu Zhixian Shen Linxiaoran Zhang Zifan Wang Hai He

Vascularization remains the principal bottleneck preventing engineered tissues from reaching clinically relevant thickness, and conventional extrusion printing cannot reconcile the low-viscosity, cell-rich bioinks required for biological function with the mechanical support needed to build suspended, branched, and hollow architectures. Embedded bioprinting resolves this conflict by transferring structural support from the ink to a yield-stress bath that locally fluidizes around the moving needle and self-heals behind it, thereby decoupling printability from ink rheology. This review presents a unified parameter-to-function analysis of extrusion-based embedded bioprinting for perfusable vascular networks. We first classify support baths along two orthogonal dimensions—post-printing fate (temporary support versus retained matrix) and physical form (granular, continuous-phase, or liquid)—and distill their behavior into four coupled rheological descriptors: yield stress, shear thinning, thixotropic recovery, and storage modulus. These parameters, together with ink–bath compatibility and process conditions, are then linked to structural fidelity in both its static (geometric accuracy) and dynamic (shape retention during crosslinking and culture) senses, and reported failure modes are consolidated into a parameter–defect–countermeasure matrix. Vascular fabrication strategies are organized into sacrificial-lumen and functional-ink direct-writing routes, and the strength of published validation is appraised through a three-level evidence framework spanning structural patency, biological maturation, and direct function, with direct embedded evidence explicitly separated from benchmarks borrowed from adjacent technologies. Persistent challenges—including the resolution gap relative to capillary dimensions, bath removal and residue control, non-transferable rheological windows, and the scarcity of long-term and interlaboratory functional data—are critically examined. Finally, we outline priorities in closed-loop intelligent process control, function-oriented design, tunable and responsive support baths, hybrid fabrication, and standardized quantitative reporting, charting a path from printable structures to predictable vascular function.

Gels doi: 10.3390/gels12111037

Authors: Ilya V. Prokopiv Kamilla B. Shishkhanova Vyacheslav S. Molchanov Kirill I. Yuzhanin Irina G. Panova Alexander A. Yaroslavov Alexei R. Khokhlov Olga E. Philippova

Global water scarcity and increasing amount of polymer waste pose two major environmental challenges that require urgent attention. One approach to addressing both these issues consists of the reuse of superabsorbent polymer (SAP) gels derived from baby diaper waste for water retention in agriculture. The present study aims to compare the water retention properties of three types of diaper SAP gels soaked with artificial urine with agrogel Aquasorb on two different soil substrates: sand and light loam. The soil hydrological constants were estimated using water retention curves obtained by equilibrium centrifugation of soil/gel mixtures containing 0.5 vol% gel. It was observed that the diaper gels soaked with artificial urine have almost the same degree of swelling and provide the same range of water available to plants as agricultural gel Aquasorb treated with the same urine—the effect of all the studied gels being more pronounced in a sand substrate. Washing from urine followed by sterilization enhances the gel swelling and water range available for plants, making these characteristics higher than those of agrogel. The water-retention properties of the sand/gel mixtures were maintained during several wetting/drying cycles. Moreover, the sterilized diaper gels similar to Aquasorb can restructure the sand substrate, reducing the pore volume, which makes them have potential to improve the erosion resistance of soil. The addition of GooN diaper gel to loamy soil improved the seedling growth of mustard (Brassica juncea L.) in a similar way to the agricultural gel Aquasorb and did not cause phytotoxic effects. Furthermore, the impact of diaper gels on seed germination was even greater than that of Aquasorb. Given these properties, diaper gels hold high potential for improving soil water retention and plant water availability, making them a promising alternative to traditional agricultural SAP products like Aquasorb.

Gels doi: 10.3390/gels12111036

Authors: Thanyalak Manopab Sawitree Pisutpiched Patompong Khaw-on Aree Deenu Kamonwan Tachai Suthaphat Kamthai

To address the environmental impact of synthetic foams, this study developed sustainable composite gel foams (CGF) based on hydroxyethyl cellulose (HEC), gellan gum (GG), and sodium alginate (Al) reinforced with rice straw (RS) pulp. The CGFs were fabricated using solution casting followed by freeze-drying, with RS pulp content varied from 0% to 4% (w/v). SEM analysis revealed that RS pulps acted as physical fiber reinforcement, promoting a more interconnected and robust porous network. FTIR spectra confirmed the successful integration of RS pulp through characteristic lignin peaks at 1540 cm−1. Adding RS pulp clearly improves the foam’s mechanical strength, notably its compressive strength and Young’s modulus, over the control sample. All of these best mechanical, water retention, and structural stability properties resulted from the 2% (w/v) RS pulp addition, which was attributed to the formation of a dense, interconnected fiber-reinforcing network and tortuous microporous channels that provided high capillary resistance and physical constraints against structural deformation. Especially, the CGF exhibited exceptional water absorption capabilities, exceeding 1900% in the initial stages. The thermal stability of CGF was also characterized via TGA, showing consistent performance across different RS pulp loads. These findings demonstrate that the RS pulp-reinforced HEC/GG/Al CGFs are promising candidates for high-performance, eco-friendly absorbent fibrous gel foam pads in food packaging applications.

Gels doi: 10.3390/gels12111035

Authors: Guy Lazovski Muriel E. Layani-Tzadka Ellen Wachtel Adira H. Marcus Asaf Nissenbaum Shiraz Kelly Shilat Ashush Shira S. Papkin Noa Elyashiv Adi Dahan Boris Smolkin Mark Grinberg Galit Bar Raz Gvishi Igor Lubomirsky

Using a custom-built, hot supercritical drying (SCD) system with automation and on-line monitoring capabilities, the drying process of silica aerogels was optimized to achieve negligible volumetric shrinkage, in addition to allowing control of the aerogel surface chemistry, from hydrophilic to “super-hydrophobic”. The procedure developed involved examining process parameters and exploring different drying media (solvents, mixtures and additives). We found that sample dissolution and bulk deformation could be minimized by introducing 2.5 vol.% H2O, in addition to ethanol or isopropanol, as the drying media. Similarly, versatility could be achieved with regard to the aerogel composition and affinity to water; mixing acetonitrile with up to 20 vol.% isopropanol can extend hydrophobic longevity from a few hours to well over a month of direct contact with water, while drying in pure isopropanol results in a “super-hydrophobic” aerogel. Alternatively, a few vol.% H2O added to acetonitrile results in a hydrophilic aerogel, with negligible carbon content.

Gels doi: 10.3390/gels12111034

Authors: Apirada Manphae Jenjira Jirum Patcharee Sittichan Yodthong Baimark

Konjac glucomannan (KGM) is a hydrophilic polysaccharide with film- and gel-forming properties. This study investigated the effects of ammonia-vapor treatment on the structural, physicochemical, morphological, and mechanical properties of thermo-compressed KGM xerogel films. KGM was mixed with water and glycerol, thermo-compressed into xerogel films, and exposed to ammonia vapor for 6, 12, 24, or 48 h. Ammonia-vapor treatment progressively increased the degree of deacetylation. The water contact angle increased, whereas moisture content, water-induced mass loss, water vapor permeability, and swelling degree decreased. The swelling degree decreased from 1072% in untreated films to 538%, 477%, 437%, and 422% after 6, 12, 24, and 48 h, respectively. Surface pits and pores became more pronounced with increasing treatment duration, while the cross-sections remained dense and continuous. A treatment duration of 12 h provided the best combined mechanical performance, with tensile strength, elongation at break, and tensile toughness increasing by 1.58-, 1.77-, and 3.58-fold, respectively, compared with untreated films. These findings demonstrate improvements in water resistance and mechanical performance. However, further evaluation of residual ammonia content, hydrated mechanical properties, fluid management, and biological safety is required before the films can be considered suitable for wound-dressing applications.

Gels doi: 10.3390/gels12111033

Authors: Zhaojun Wu Guodong Tang Lihuang Wang Shuo Huang Huanhuan Wang Yantong Zhao Jiacheng Wang Chengling Pan Qi Liu Wenqi Yan

Aqueous zinc batteries are promising for safe and durable energy storage, but sluggish Zn2+ transport and unstable Zn interfaces limit their cycling performance. Reducing the water content of hydrogel electrolytes can mitigate parasitic reactions, yet preserving ionic conduction remains challenging. Here, we report a water-lean double-network gel electrolyte (DNGE) formed by in situ polymerization of acrylamide within a bacterial cellulose (BC) scaffold in ZnSO4 solution. The resulting BC/polyacrylamide (PAM) architecture combines a water content of 20.5 wt% with an ionic conductivity of 11.72 mS cm−1. Electrochemical measurements and characterization of cycled electrodes indicate reduced polarization, more uniform Zn deposition and less accumulation of crystalline byproducts. With DNGE, Zn||Zn symmetric cells sustain plating and stripping for ~1300 h at 0.5 mA cm−2 and 0.5 mAh cm−2. Zn|I2 full cells deliver ~150 mAh g−1 after 7580 cycles at 10 C. The corresponding pouch cells deliver 169 mAh g−1 after 100 cycles and power a toy car. The BC/PAM architecture therefore enables reduced water content while preserving efficient ion transport and stable Zn electrochemistry.

Gels doi: 10.3390/gels12111032

Authors: Iliana Fuentes-Camargo Julia Liliana Rodríguez-Santillán Iván Salgado Dulce María González-García Ricardo Santillán-Pérez Rodrigo Jiménez-Gallegos

The removal of synthetic dyes from industrial wastewater remains an important challenge in water treatment. In this work, poly(vinyl pyrrolidone-co-acrylamide) hydrogels were synthesized by free-radical polymerization using 2–6 wt% N,N′-methylenebisacrylamide (MBA) as a crosslinking agent and evaluated for methyl orange (MO) adsorption. The hydrogels were characterized by attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Their swelling behavior was studied at different temperatures, and adsorption experiments were carried out at 25 °C using different hydrogel dosages. Equilibrium data were fitted to the Freundlich, Sips, and Flory–Huggins (FH) models by nonlinear regression. The FH model was fitted using weighted least squares, while model comparison was performed using the corrected Akaike information criterion (AICc). Swelling was highest at 25 °C and decreased as the MBA content increased. The thermal analyzes showed similar behavior among the hydrogels, with glass transition temperatures close to 182 °C. MO removal increased rapidly at low adsorbent dosages and then tended toward a plateau. H18, containing 5 wt% MBA, showed the highest Freundlich affinity constant KF=1.4221 (mg/g) (L/mg)0.4928. This result indicates that an intermediate crosslinker content provides suitable network accessibility while maintaining the hydrogel structure. Freundlich gave the best statistical fit for most hydrogels, whereas Sips performed better for H16. Overall, the results indicate that the amount of crosslinker affects both swelling and MO adsorption.

Gels doi: 10.3390/gels12111031

Authors: Junge Li Fei Han Xinyu Li

Heavy-metal ions, organic dyes, antibiotics, and microplastics (including nanoplastics), which can bioaccumulate and are potentially toxic, pose serious threats to aquatic ecosystems and human health. Traditional adsorbents face limitations in complex wastewater, as they often exhibit poor selectivity, low mechanical strength, and poor reusability. Cellulose-based double-network (DN) hydrogels, which address these limitations by integrating two functionally complementary networks, consist of a rigid cellulose-based first network that maintains structural integrity and provides a biodegradable skeleton, and a flexible second network that enhances toughness, swelling, mass transfer, and functional-group accessibility. This review summarizes recent progress in cellulose-based DN hydrogels, covering preparation strategies, network composition, and pollutant adsorption applications. Heavy-metal ions are captured mainly through coordination complexation and ion exchange. Organic dyes and antibiotics are removed through electrostatic interactions, hydrogen bonding, and π–π interactions. Microplastics are adsorbed mainly through physical interception and electrostatic interactions. The recyclability of these hydrogels is evaluated in terms of regeneration efficiency, capacity retention, and structural stability. Finally, future research trends are outlined, including new green preparation strategies, evaluation in real wastewater systems, and large-scale production and application.

Gels doi: 10.3390/gels12111030

Authors: Andrei A. Uzhegov Mikhail V. Kaluga Aleksandr I. Buglakov Alexander V. Chertovich

Active polymer gels provide useful models for biological and synthetic nonequilibrium soft matter, yet most theoretical and simulation studies of such systems have focused on effectively infinite active networks and have therefore neglected free-surface effects. Here, we use coarse-grained computer simulations within the active Brownian particle framework to investigate single microgels in which activity is assigned directly to individual monomer units. We examine the effects of subchain length, active-monomer fraction, localization of activity on subchains or cross-links, and radial distributions of active units. Activity induces pronounced microgel compression, which becomes stronger with increasing subchain length and, among the systems studied, reaches its greatest magnitude at a low active fraction of 5%. The collapsed structures can exhibit a dense, heterogeneous core surrounded by a shell of strongly extended subchains. Activity localized at cross-links produces substantially weaker compression than activity distributed along subchains, whereas surface-localized activity enhances collapse and core-localized activity suppresses it. By mapping the Péclet number onto an effective Flory–Huggins parameter, we show that the swelling behavior of partially active microgels near the θ point can be related to Flory–Rehner theory, although important structural differences from passive collapse remain.

Gels doi: 10.3390/gels12111029

Authors: Carla Padilla Alejandra Ortega Guillermina Burillo

Xanthan gum (XG) and acrylamide (AAm) hydrogels were synthesized using gamma radiation. The novelty lies in the use of a simple methodology to obtain two different architectures, thereby tailoring their physicochemical properties. The first system is a comb-type hydrogel (net-AAm)-g-XG, where the crosslinking of AAm and the XG grafting were carried out in a single step via gamma radiation. The second system consists of an interpenetrating network (IPN) (net-XG)-inter-(net-AAm), where XG was crosslinked with citric acid and then AAm was crosslinked by gamma radiation in the presence of XG gel. Good degrees of grafting (60%) and interpenetration (75%) were obtained at 8 kGy for both systems. Comb-type and IPN hydrogels showed a porous structure, but the pore size was smaller in the interpenetrating network because this architecture has less internal space due to the presence of a second network. Morphological differences affected water absorption and drug loading/release properties. The comb-type showed its maximum swelling (900%) at 24 h, regardless of the grafting amount; while the IPN exhibited a swelling of 400–600% at 3 h, depending on the interpenetration degree. Both systems allowed for ciprofloxacin loading, but release was faster in the IPN (100 min) than in the comb-type hydrogel (300 min).

Gels doi: 10.3390/gels12111028

Authors: Gabija Mikailaitė Gintarė Dyglė Vilma Petrikaitė Rimantė Vinauskienė Viktorija Eisinaitė Daiva Leskauskaitė

This study aimed to develop a novel method for preparing agar-based emulsified fluid gels as a thickened enteral feeding formula using different oil-structuring approaches: no emulsifier, the emulsifier polyglycerol polyricinoleate (PGPR), or monoglycerides/diglycerides of fatty acids (MDFA), which function as both emulsifiers and gelling agents. We examined sample stability, oil-holding capacity, particle sedimentation, size, morphology, rheological and textural properties, and the maximum injection force required to deliver the system through syringes fitted with tubes of different diameters. Adding PGPR, decreased the polydispersity index (span 2.21), apparent viscosity (588.88 mPa·s), and yield stress (0.39 Pa), reducing the force required to inject the fluid gel through the syringe. MDFA addition destabilized the system, resulting in a high polydispersity index (span 14.07) and reduced stability (68.75% under static and 79.64% under dynamic conditions). While the fluid gel with oil without emulsifier/stabilizer exhibited high stability (100%), it also showed high viscosity and yield stress values, affecting the increase in maximum injection force, which is a negative aspect. The results showed that such a different oil structuring approach affects the microstructure of the fluid gel formulations, resulting in differences in stability and rheological properties. This study provides mechanistic insights into the structural relationships between suspended agar particles and oil droplets, providing a feasible strategy for designing agar-based fluid gels with a lipophilic phase. The PGPR-containing fluid gels could serve as enteral nutrition formulations for the targeted delivery of lipophilic and hydrophilic nutrients and drugs. While lipophilic phase inclusion without an emulsifier or stabilizer also looks very promising, the high viscosity and yield stress should be reduced by adjusting the fluid gel preparation conditions.

Gels doi: 10.3390/gels12111027

Authors: Siu Kan Law Albert Wing Nang Leung Chuanshan Xu

The objective of this study was to explore the emerging role of celastrol-loaded hydrogels as advanced biomaterial platforms for tissue engineering and regenerative medicine. Traditional Chinese medicine active ingredients face limitations from rapid clearance and low bioavailability. This study examines how integrating the pentacyclic triterpene quinone methide, celastrol, into controlled-release natural and synthetic hydrogels overcomes these challenges to modulate the local injury microenvironment. A structured literature search was conducted across multiple databases, including PubMed, Scopus, Web of Science, and CNKI, covering publications from January 2000 to March 2026. Data including hydrogel networks, spatial–temporal release kinetics, and therapeutic outcomes were extracted and synthesized across 15 selected preclinical studies. The findings indicate that celastrol exhibits a narrow therapeutic window and severe multi-organ toxicity. However, localization within hydrogels shields host organs from apoptotic injury while ensuring zero-order diffusion or stimuli-responsive release. Mechanistically, these systems accelerate anatomical repair by shifting tissue microenvironments from chronic inflammation and fibrosis to a pro-healing state. This therapeutic transition is driven by a multi-target cascade involving NF-κB pathway suppression, Nrf2/HO-1 antioxidant activation, HSP70 cytoprotection, M2 macrophage polarization, and pro-fibrotic TGF-β/Smad signaling inhibition. Biomimetic natural polymer backbones further eliminate carrier-induced stress, providing structural cues to support cell transplantation, stem-cell attachment, and endogenous extracellular matrix remodeling. Celastrol-loaded hydrogels extend therapeutic effects on functional tissue regeneration rather than mechanical scarring. Clinical translation depends on the safety assessments for degradation tuning, matrix reliability, and long-term in vivo pharmacokinetics.

Gels doi: 10.3390/gels12111026

Authors: Héctor Iván Meléndez Ortíz Lorena García Uriostegui

Gels are versatile soft materials that provide an important link between fundamental research and technological innovation [...]

Gels doi: 10.3390/gels12111025

Authors: Jinhuan Liu Tianhui Wang Yongtao Jiang Mujie Ju Wei Zhao Samah Attia Algharib Aizhi Han Wanhe Luo

The obligate intracellular parasitic nature of Lawsonia intracellularis (L. intracellularis) enables it to evade host immune clearance and conventional antimicrobial action, leading to considerable therapeutic challenges and high recurrence rates. Current strategies, including vaccination and conventional antibiotic therapy, remain constrained by incomplete protection and insufficient intracellular drug delivery, underscoring the urgent need for novel oral targeted delivery strategies. Thus, the valnemulin-derived carbon dots were prepared via a hydrothermal method and sequentially encapsulated with poloxamer, high-methoxyl pectin, and sucrose to assemble a three-layer core–shell VPP NPs to address these limitations. The VPPS NPs was optimized using response surface methodology and systematically evaluated the resulting system for physicochemical properties, pH and pectinase dual-responsive release behavior, targeted antibacterial efficacy, and in vivo therapeutic performance and biosafety. Physicochemical characterization showed that VPPS NPs had a typical core–shell structure and a three-dimensional porous network with a final particle size of 122.9 ± 8.7 nm, and Fourier transform infrared spectroscopy and X-ray diffraction confirmed successful assembly and intermolecular interactions among the components. In vitro release studies revealed pH/pectinase dual-responsive release behavior, characterized by partial acid resistance in simulated gastric fluid (11.4 ± 1.6% cumulative release at 2 h) and rapid release in the neutral intestinal environment (97.8 ± 2.0% at pH 7.4), with release significantly accelerated in the presence of pectinase (72.4 ± 1.7% vs. 32.8 ± 2.8% without pectinase). VPPS NPs were efficiently internalized by intestinal epithelial cells, resulting in substantially higher intracellular drug accumulation than free drug (25.2 ± 2.9 μg/mg protein vs. 0.03 ± 0.003 μg/mg protein), and could directly disrupt the cell wall and membrane structures of intracellular L. intracellularis. Furthermore, VPPS NPs achieved 100% survival and cure rates in infected mice, which are significantly higher than those of the commercial VH solution (70% and 50%, respectively), while restoring intestinal barrier function, alleviating oxidative stress, and modulating inflammatory responses. Biosafety evaluation confirmed the favorable biosafety profile of VPPS NPs. Collectively, VPPS NPs accomplished efficient targeted therapy against L. intracellularis infection through multi-level synergistic actions, offering an innovative strategy and technological platform for the oral treatment of proliferative enteropathy.

Gels doi: 10.3390/gels12111024

Authors: Farinawati Yazid Muhammad Da’in Yazid Nur Azurah Abdul Ghani Nurrul Shaqinah Nasruddin Rohaya Megat Abdul Wahab Kok-Lun Pang Thanaphum Osathanon Shahrul Hisham Zainal Ariffin

Intraoral mucosal wounds face challenges around continuous salivary clearance, mechanical shear stress and polymicrobial exposure. Despite growing interest in topical interventions, a comprehensive synthesis of the biomaterial’s effective concentrations, bioadhesion strategies and molecular mechanisms remain limited. This systematic review aims to evaluate preclinical animal studies on polymeric hydrogels, bioadhesive biomaterials and topical therapeutics for oral mucosal repair. Following PRISMA 2020 guidelines (PROSPERO: CRD420261443129), three electronic databases were searched (PubMed, Scopus, and Web of Science) until June 2026. Thirty-five preclinical animal studies were evaluated across natural biopolymers, chemically modified/semi-synthetic biopolymers and synthetic hydrogel networks. The reported outcomes were vehicle and dose-dependent, with bioadhesive formulations demonstrating wet tissue adherence and prolonged residence time. The biomolecular findings reveal discrete model-specific associations rather than single unified mechanisms. Formulation of these biomaterials is linked to elevated pro-angiogenic markers (VEGF, CD31), extracellular matrix reorganisation (TGF-β1, Col1A1) and suppression of pro-inflammatory mediators (iNOS, IL-1β and TNF-α). SYRCLE assessment identified low risk selection/attrition bias, but performance/detection bias showed high risk due to unblinded applications. Although topical biomaterials facilitate oral mucosal repair in preclinical models, clinical translation remains constrained by animal model heterogeneity, non-standardised dosing metrics and methodological risk of bias.

Gels doi: 10.3390/gels12111023

Authors: Haiyan Yu Kaiyao Chen Zuyou Shi Fangzhou Zhao Mu Du

Rapid charging and high-rate operation generate substantial heat in lithium-ion batteries, and insufficient heat dissipation can cause local heat accumulation and increase the risk of thermal failure. Macroporous metallic gels, represented by high-porosity open-cell metal foams, provide continuous heat transfer pathways and are promising media for battery thermal management. However, surface microdefects inevitably introduced during manufacturing and service can alter their thermal transport properties and consequently affect the accuracy of battery thermal safety prediction. In this study, open-cell aluminum and nickel macroporous metallic gels with spherical protrusions and depressions on the ligament surfaces were investigated. The effects of pore size (1–50 mm), contact angle (0–85°), defect volume fraction (0–10%), defect bottom radius (5–200 μm), and ambient temperature (300–400 K) on conductive, radiative, and total effective thermal conductivity were systematically investigated. The results show that increasing the protrusion content enhances heat conduction, whereas increasing the depression content significantly reduces the total effective thermal conductivity, with the maximum reduction approaching 90% when the defect content reaches 10%. Increasing the defect radius further strengthens the influence of depressions, particularly at smaller pore sizes. The calculated thermal conductivities of aluminum and nickel gels were applied to cylindrical and prismatic battery models to evaluate heating times from 300 to 350 K. Surface depressions slightly shortened the heating time, whereas protrusions generally prolonged it. The largest variation was observed, ranging from 153.415 to 153.500 s for cylindrical cells with nickel gels. These results provide a theoretical basis for defect-aware battery thermal management and safety prediction.

Gels doi: 10.3390/gels12111022

Authors: Chonghao Wang Huijie Dong Shangde Sun Yan Chen Fengyan Wang Linna You Manyi Wang Derya Kahveci Qian Hu

Traditional oleogels prepared using monoglycerides (MGs) were found to exhibit needle-shaped crystals, relatively large crystal sizes, coarse crystal aggregation, loose network architecture and inferior structural stability, which resulted in low viscosity and poor structural recoverability. To address the issue, multiple gelling agents were applied to prepare a novel oleogel. Results demonstrated that the composite of polyglyceryl esters of fatty acids (PGEFs) and MGs showed excellent properties. Application of 3% PGEF intercalated into MG lamellar spaces, facilitated ordered lipid stacking and constructed dense, continuous layered crystalline networks while retaining the intrinsic hydrogen-bonding interactions of oleogels. The crystal growth shifted from random one-dimensional aggregation to well-organized two-dimensional lamellar stacking, accompanied by an increase in nucleation density. Accordingly, the composite oleogels exhibited notable improvements in network compactness (10.22%), oil binding capacity (99.17%) and elasticity-based rheological stability (82.03%). However, LEC was intercalated into MGs to refine crystals and strengthen networks, whereas over-dosage was observed to destroy gel integrity. Inferior anti-staling performance was obtained compared with PGFE systems. During toast preparation, the dense PGEF-MG crystalline networks acted as a strong physical barrier, which effectively suppressed water migration and starch retrogradation, improved moisture retention and anti-staling, and improved the uniformity and structural stability of crumbs. The staling rates of the toast were decreased from 116.68% to 5.27%, and baking loss was decreased by 44.76%. This study elucidated the molecular assembly and crystal regulation mechanisms of PGEF-MG oleogels, laying a solid theoretical foundation for the development of high-performance plant-based oleogels as fat replacers for bakery use.

Gels doi: 10.3390/gels12111021

Authors: Shuqi Lou Zhanpeng Liu Zixuan Fan Hongxin Jiang Xinwei Wang Shuangqi Tian Zehua Liu Renyong Zhao

Hydrogels based on starch–fatty acid salt complexes were developed for targeted substance delivery. X-ray diffraction analysis confirmed that all complexes exhibited the typical V-type crystalline structure. Differential scanning calorimetry revealed structural differences between the complexes: the normal maize starch–sodium laurate complex formed a less ordered VI-type structure, whereas the maize starch–sodium palmitate samples displayed a coexistence of both VI- and VII-type inclusion complexes. This discrepancy is likely attributable to the difference in hydrophobicity between sodium laurate and sodium palmitate. Following calcium ion-induced gelation, oscillatory frequency sweep measurements revealed that the storage modulus (G′) exceeded the loss modulus (G″) for all hydrogel samples during detection, indicating that the hydrogels maintained a predominant elastic network structure. During simulated gastrointestinal digestion, a substantial portion of the released calcium ions and vitamin D was observed in the intestinal phase, suggesting that this starch–fatty acid salt complex-based hydrogel system holds promise as a viable carrier for the targeted delivery of bioactive compounds in food applications.

Gels doi: 10.3390/gels12111020

Authors: Linxiaoran Zhang Shengxiang Chen Hengxiang Liu Zishuai Chen Ziwei Liu Yongjie Li Guojun Xu Zifan Wang Hai He

Ablative and non-ablative energy-based procedures—lasers, intense pulsed light, radiofrequency and ultrasound—rejuvenate skin by inflicting controlled, mechanism-specific injury, yet the resulting perturbation can drive erythema, barrier disruption, dyschromia and, occasionally, scarring. Hydrogel dressings are increasingly used to manage this recovery window, but design principles specific to the post-procedure microenvironment remain scattered. This narrative review synthesises how each energy modality perturbs the cutaneous microenvironment across five coupled dimensions—thermal load, barrier integrity, inflammation, pigmentation and a merged microbiome–oxidative axis—and maps six hydrogel design strategies onto these perturbations: cooling and moist barrier restoration, antioxidant and bioactive gas delivery, immunomodulation, antibacterial and photothermal design, anti-pigmentation strategies, and active delivery against aberrant remodeling. We then grade the evidence with an author-defined, scenario-adapted rubric, revealing a steep evidence cliff: 133 unique cited source records were reconciled, of which 85 original studies were graded; only three randomized trials tested gel-based formulations directly after energy-based procedures (two tested water-swollen hydrogels under the strict definition; the cliff conclusion is unchanged), and 41 of these 85 graded original studies remain at the in vitro or small-animal stage. The other 48 records comprise 34 reviews and 14 context, methods, regulatory, or out-of-scope records, each with an explicit reason for non-grading. The article uses a structured citation-level evidence audit and is not a systematic or scoping review. Evidence from burns, chronic wounds, injectable fillers, melasma, ex vivo skin, or infected animal wounds is treated as indirect and is not used to infer efficacy after aesthetic energy-based procedures. Finally, we dissect translational bottlenecks—regulatory classification and the resulting scissors gap between laboratory innovation and registration feasibility, the sterilization paradox, and manufacturing scale-up—and propose a staged roadmap from bench to clinic. Hydrogels are poised to become precision recovery platforms rather than passive dressings, provided that design, evidence and regulation advance together. Personalized, closed-loop and bioactive-cargo dressings remain research directions for prospective, adequately controlled, procedure-specific evaluation rather than established clinical capabilities.

Gels doi: 10.3390/gels12111019

Authors: Hiluf T. Fissaha Duckjong Kim

Freezing conditions are commonly used to regulate pore formation in aerogels, yet their influence on the reversible water-sorption performance of salt-containing aerogels remains poorly understood. Herein, LiCl/CaCl2–poly(N-isopropylacrylamide)/konjac glucomannan (LC/PN@KGM) aerogels with comparable salt loadings of 60.4 and 59.5 wt% were prepared by freezing at −70 °C and in liquid nitrogen (LN2), respectively. The two aerogels exhibited comparable crystalline and chemical characteristics. In contrast, morphological characterization revealed distinct pore structures associated with the different freezing conditions. The LN2-frozen aerogel (LC/PN@KGM-LN2) exhibited improved reversible water-sorption performance compared with the aerogel frozen at −70 °C (LC/PN@KGM-70). Its working capacity (WC) increased from 3.03 ± 0.14 to 3.25 ± 0.13 g g−1, while its desorption efficiency increased from 93% to 95%. LC/PN@KGM-LN2 also exhibited faster adsorption and desorption kinetics. The adsorption rate increased from 0.31 ± 0.01 to 0.39 ± 0.01 g g−1 h−1, while the desorption rate increased from 1.33 ± 0.17 to 1.58 ± 0.26 g g−1 h−1. Compared with LC/PN@KGM-70, LC/PN@KGM-LN2 exhibited higher working capacity, desorption efficiency, and adsorption and desorption rates under the investigated conditions. The improved performance is associated with differences in pore morphology, highlighting the importance of freezing-induced pore-structure control in enhancing reversible water sorption.

Gels doi: 10.3390/gels12111018

Authors: Yanjie Hou Bingyan Liu Ziyu Zhao Yaping Liu Peifeng Li

Polysaccharide gels as food matrix with excellent mechanical properties hold great potential in the design and development of dysphagia foods. This study investigated the structural properties of Dendrobium officinale polysaccharide (DOP)/xanthan gum (XG) gel in the presence of different carbohydrates, including glucose (Glu), sucrose (Suc), xylo-oligosaccharide (XOS), and sodium alginate (SA). The influence of different carbohydrates on DOP/XG gel microstructure, rheological properties, and intermolecular interactions was analyzed. The results suggested that the mixture with the addition of SA at 0.4% (w/v) exhibited excellent hardness, gel strength, and denser network. The addition of Glu, Suc, and XOS at 10% (w/v) enhanced the water adsorption capacity of DOP/XG gel, modified its amorphous structure, and reduced its thermal stability, while exerting no significant influence on gel strength and rheological properties. IDDSI testing showed that all samples had textural characteristics consistent with those of Level 6 foods. Overall, this study elucidates the effects of different carbohydrates on the structure and properties of DOP/XG gel, thereby providing a theoretical basis for the design and development of polysaccharide gel-based foods for dysphagia management

Gels doi: 10.3390/gels12111017

Authors: Eun-Ho Lee Ji Hyeon Lee Kang Song Da-Eun Kim Yong-Jo Lee Byeong-Ryeol Ryu Jung Dae Lim Hae Ryong Choi Dong Hyuk Youn Sung-Min Kang

Irritant contact dermatitis (ICD) is a common inflammatory skin disease caused by direct exposure to exogenous irritants, characterized by skin barrier disruption and persistent inflammation. Here, we developed a 169-well hanging-drop platform for the uniform and scalable generation of human follicle dermal papilla cell (HFDPC)-derived organoids. The honeycomb-shaped microwell array promoted gravity-driven cellular aggregation and controlled organoid formation, while Matrigel provided an extracellular matrix (ECM)-rich three-dimensional (3D) microenvironment supporting tissue-like organization. Compared with conventional Matrigel-based culture, the proposed platform enabled improved control of organoid size and morphology, reproducible formation, and high-throughput production. The platform generated highly uniform organoids with a mean diameter of 116.55 ± 4.36 μm (mean ± SD) and a coefficient of variation of 3.74%, while integration with a standard 6-well plate enabled simultaneous production of up to 1014 organoids. In an ICD mouse model, transplantation of the organoids accelerated skin repair and alleviated inflammation, accompanied by reduced oxidative stress, restored SirT1 expression, attenuated PI3K/AKT phosphorylation, and suppressed Th1/Th17-mediated immune responses. These findings indicate that the combination of a 169-well hanging-drop architecture with a Matrigel-based 3D microenvironment provides a controlled and scalable platform for HFDPC organoid generation, with therapeutic potential demonstrated in an ICD mouse model.

Gels doi: 10.3390/gels12111016

Authors: Svetlana Bratskaya Anna Skatova Mariia Maiorova Andrey Golub Yuliya Privar Alexey Golikov Roman Goncharuk Andrey Boroda

The cryoconcentration-driven cross-linking of carboxymethyl cellulose (CMCell) with 1,4-butanediol diglycidyl ether (BDDE) was investigated to overcome the problem of the low cross-linking efficiency of FDA-approved BDDE at room and elevated temperatures. Two distinct regimes of network formation were identified depending on the NaOH concentration: a continuous increase in the cross-linking density over time in 0.2% and 0.4% NaOH, and rapid cross-linking followed by partial CMCell degradation in 0.8% NaOH. The threshold conditions for the formation of mechanically stable CMCell cryogels were found at 0.2% NaOH and 5 days of cross-linking at a BDDE:CMCell molar ratio of 1:10. By varying the NaOH concentration and cross-linking time, CMCell cryogels with a toughness from 2.2 ± 0.3 to 8.1 ± 0.1 kJ/m3, a compressive strength from 8.6 ± 1.4 to 26.5 ± 0.6 kPa, and a total swelling from 3177 ± 155 to 5651 ± 367% were obtained. Cross-linking in the 0.4% NaOH solution provided the widest processing window, allowing for the gradual tuning of cryogel properties via the cross-linking time variation. Large pores (72–111 µm) and relatively low swelling of the pore walls ensured a high permeability of the cryogels under gravity. The human dermal fibroblast viability remained above 95% after 48 h in contact with the cryogels, independently of the cross-linking conditions.

Gels doi: 10.3390/gels12111015

Authors: Anca Daniela Raiciu Carmen Elisabeta Manea

Plant-derived hydrogels are promising topical delivery systems and wound dressings, but their performance depends on both the botanical preparation and the polymer matrix. This narrative review examines cutaneous formulations containing Aloe vera, Matricaria chamomilla, Centella asiatica, Vitis vinifera skin extracts, and curcumin associated with Curcuma longa, focusing on ingredient characterization, formulation design, release, and biological evidence. The reviewed studies show that hydrogel composition influences swelling, mechanical properties, and bioactive release. Biological findings include antioxidant and antimicrobial activity, cellular responses, and wound-healing-related outcomes in animal models. However, comparisons are limited by inconsistent extract characterization, incomplete dose reporting, heterogeneous biological models, and variable controls. Asiaticoside release does not represent the behavior of the entire Centella extract, while the contribution of chamomile cannot be isolated in formulations containing silver sulfadiazine. Similarly, the benefits of hydrogel incorporation over simpler formulations remain insufficiently established, and human evidence for the specific systems is limited. Future studies should prioritize reproducible extract characterization, accurate measurement of active content, appropriate component controls, and dose-matched comparisons linking release to biological outcomes. These steps are essential to determine the added value of hydrogel delivery and support clinical evaluation.

Gels doi: 10.3390/gels12111014

Authors: Chengyue Qiao Shige Wang

Inflammatory bowel disease (IBD) is a chronic and relapsing gastrointestinal disorder that requires long-term management, while current therapies remain limited by premature drug loss, systemic exposure, and insufficient local retention. Stimuli-responsive hydrogels provide a local delivery platform whose network structure changes in response to gastrointestinal and inflammatory microenvironments, thereby affecting drug protection, retention, and release. This review discusses hydrogel network transitions, crosslinking strategies, and drug-loading approaches, together with the effects of pH, redox conditions, enzymes, inflammatory signals, and temperature on hydrogel behavior. Oral, rectal, and endoscopic delivery are examined in relation to gastrointestinal protection, local retention, mucosal adhesion, and lesion-localized therapy. The therapeutic effects of these systems include epithelial barrier protection and repair, regulation of oxidative stress and immune responses, modulation of the gut microbiota, and mucosal regeneration. Differences in gastrointestinal and inflammatory environments are also considered in relation to hydrogel response, local drug delivery, and long-term performance. Furthermore, the existing bottlenecks restricting their clinical translation are highlighted, and feasible directions for the follow-up optimization of responsive hydrogel systems for IBD treatment are prospected.

Gels doi: 10.3390/gels12111013

Authors: Margarida Fernandes Cátia Correia Daniela Peixoto Natália M. Alves

Chitosan-based thermosensitive hydrogels are promising biomaterials for tissue engineering owing to their biocompatibility, biodegradability, and ability to undergo a sol–gel transition at physiological temperature. In this study, we developed hydrogels based on catechol-modified chitosan (Chit-Cat) to improve tissue adhesion under wet conditions and combined them with silver-doped bioglass nanoparticles (Ag-BGNPs) to enhance antibacterial activity. The hydrogels were formed via electrostatic interactions, using β-glycerophosphate (β-GP) as a crosslinker. The resulting hydrogels demonstrated suitable shear-thinning behaviour for injectability and cytocompatibility against L929 fibroblasts (~84%) and human osteoblast cells (~92%). Overall, the developed thermosensitive hydrogels combine physiological-temperature gelation, enhanced adhesion, antibacterial activity, and cytocompatibility, highlighting their potential as multifunctional injectable biomaterials for tissue engineering and bone regeneration.

Gels doi: 10.3390/gels12111012

Authors: Tian Wang Zeyang Ma Ke Hu Dan Xiong Li Song

Polysaccharide–protein composite food gels, owing to their high structural tunability, favorable printability, and nutritional functionality, have emerged as an important material platform for 3D/4D food printing. However, existing reviews have largely focused on material preparation or printing technologies, with limited analysis of polysaccharide–protein synergism and the quantitative links between molecular interactions, rheology, printability, and functionality. This review uses VOSviewer to analyze co-occurrence patterns in the literature on gels and food printing over the past decade. It examines how molecular interactions and crosslinking regulate gel networks and rheology, and how formulation, printing parameters, and post-processing affect texture, water-holding capacity, printing fidelity, and structural stability. Printability is evaluated through yield stress, shear-thinning, thixotropic recovery, and G′/G″, alongside a comparison of six printing technologies. Recent advances in 4D-printed deformable gels responsive to temperature, humidity, pH, and microwave stimulation are further summarized, with particular emphasis on their potential applications in smart foods, dysphagia-oriented diets, and functional delivery systems. Finally, current research trends are discussed, highlighting a shift from empirical formulation optimization toward multiscale structural regulation, elucidation of dynamic response mechanisms, and health-oriented personalized food design. This review provides a conceptual and practical framework for advancing both the fundamental understanding and industrial application of polysaccharide–protein composite gels in food printing.

Gels doi: 10.3390/gels12111011

Authors: Xinying Xia Junyong Chen Defang Pan

To address the resource-intensive and environmental drawbacks of petroleum-based thermal-insulating foams, valorizing agro-waste to produce multifunctional insulation materials is a promising route. Herein, wheat-husk agro-industrial by-product was used to fabricate cellulose–silica composite aerogels (CSA) through [BMIM]Cl-mediated cellulose dissolution–regeneration, coupled with sodium-silicate impregnation followed by in situ formation of silica and hexamethyldisilazane (HMDS) surface silylation. Different from conventional strategies that introduce pre-synthesized silica nanoparticles via blending or post-impregnation, this in situ strategy enables intimate hydrogen-bonded interfacial contact and uniform dispersion of silica within the three-dimensional cellulose network. The structure–property links among cellulose solid content, porous-skeleton evolution, mechanical, thermal-transport, flame-retardant and wetting performances were systematically explored. Raising cellulose content densified the interpenetrating cellulose–silica network, which is speculated to enhance intermolecular non-covalent interactions; CSA-10 achieved 1.14 MPa compressive stress under 6% strain. Owing to the hierarchical porous architecture suppressing gas–solid dual-path heat transfer, aerogels maintained low thermal conductivity (0.035–0.041 W·m−1·K−1). CSA-6 exhibits fast self-extinguishing performance, with 55% residue at 800 °C. HMDS grafting introduced trimethylsilyl groups, delivering water contact angles of 129.3–146.9°. This work achieves high-value valorization of wheat-husk waste and provides candidate multifunctional aerogels for energy-saving building insulation.

Gels doi: 10.3390/gels12111010

Authors: Wencai Bai Mengjie Li Bo Ding Min Hu Yongqiang An Haoyang Xie Qingyu Wen Lishui Chen

Konjac glucomannan (KGM) is a renewable polysaccharide with high hydration capacity, abundant hydroxyl groups, and tunable gelation, making it a versatile platform for hazardous-contaminant remediation. Chemical functionalization and hybridization with inorganic, porous, magnetic, photoactive, and photothermal phases have extended KGM systems from adsorption to selective ion capture, photo-assisted treatment, and solar-driven water purification. This review critically links KGM molecular structure and network architecture to contaminant speciation, interfacial interactions, mass transfer, and treatment performance, and assesses the evidentiary limits of fitted Langmuir capacities, pseudo-second-order kinetics, and FTIR/XPS assignments. Representative studies demonstrate strong potential for cationic-dye adsorption, uranium removal from carbonate-containing and real mine wastewater, and solar-driven evaporation. However, performance remains highly dependent on solution chemistry, material state, and experimental configuration. Future progress should move beyond record capacities toward quantitative structure–interaction–transport–fate relationships, discriminating mechanistic experiments, environmentally relevant concentrations, authentic-water validation, continuous-flow operation, contaminant-fate analysis, and process-level sustainability assessment.

Gels doi: 10.3390/gels12111009

Authors: Sabuj Chandra Sutradhar Nipa Banik Joung Jung Gun Md. Shahriar Ahmed Hohyoun Jang Whangi Kim Md. Lemon Hasan Mohammad Faysal Al Mazid Md. Mahmudul Hasan Kyung-Wan Nam Mobinul Islam

Biopolymer-based hydrogels offer adaptable platforms for localized cancer therapy by regulating administration, tissue retention, payload protection, and therapeutic release. This review critically examines polysaccharide-, protein-, peptide-, and polynucleotide-based hydrogels, relating polymer composition, crosslinking, network architecture, swelling, degradation, and payload interactions to pharmaceutical and biological performance. Physical, chemical, enzymatic, and ionic gelation strategies are evaluated alongside diffusion-, swelling-, affinity-, and degradation-controlled release and their mathematical interpretation. Macrogels, microgels, nanogels, and hybrid systems are compared according to administration route, disposition, and oncology-relevant function. The review further distinguishes local placement, passive accumulation, ligand-mediated cellular interactions, and endogenous or externally triggered release. Applications in chemotherapy, radiotherapy, immunotherapy, hyperthermia, and phototherapy are assessed across colorectal, gastric, liver, pancreatic, and breast cancers. Marketed devices, patented technologies, clinically evaluated systems, and regulatory considerations are also examined. Despite extensive preclinical development, translation remains constrained by polymer variability, incomplete pharmaceutical characterization, sterilization and scale-up challenges, uncertain degradation and clearance, and limited clinically representative evidence. Progress will depend on clinically defined product design, reproducible manufacturing, quantitative disposition and safety assessment, and demonstration of meaningful benefit over existing therapeutic or procedural alternatives.

Gels doi: 10.3390/gels12111008

Authors: Adriana-Gabriela Schiopu Mihai Oproescu Paul Mereuță Ecaterina Magdalena Modan Sorin Georgian Moga Miruna-Adriana Ioța Alexandru Berevoianu Ștefan Mira Marian-Cătălin Ducu Elena Andreea Vijan Daniela Istrate

Hen eggshell is an abundant, calcite-rich food waste that is usually valorised by calcination at 800–1000 °C, an energy-intensive step that releases its carbonate CO2 and destroys its biogenic microstructure. Low-temperature routes that keep the calcite intact have received little attention, and their effect on the structure and functions of geopolymer gels is unknown. This work examined whether eggshell conditioned at only 250 °C (ES-250) can replace 10 wt% of the metakaolin in a geopolymer gel, and what it changes. ES-250 remained pure biogenic calcite, with intracrystalline vesicles and residual organic matter, and the route needs ≈3–6 times less heat than calcination, including drying. In the hardened binder, ES-250 persisted as discrete 2–5 µm calcite particles without detectable Ca diffusion into the aluminosilicate gel. The Si–O–T bonding, the total pore volume and the N2-accessible porosity (≈41%) were preserved, and only the BET surface area decreased (36.2 → 31.6 m2 g−1). Dye uptake in the dark was maintained, but the strong antibacterial effect of the plain geopolymer, which left no culturable Escherichia coli after 4 h, was largely lost (22–34% reduction). Low-temperature-conditioned eggshell is therefore a decarbonation-free, structurally inert filler for geopolymer gels, but not a functional additive.

Gels doi: 10.3390/gels12111007

Authors: Kenneth S. Kilgore Ronaldo Barcellos De Santana

Periodontal disease (PD) is a multi-factorial condition that may lead to tissue destruction and tooth loss. Multirooted teeth are at high risk due to the furcation space where roots diverge, and new regenerative therapies are needed to support complete repair. This study assessed safety and preliminary efficacy of an injectable piezoelectric-based hydrogel (Ambrilux Dental Gel) in a canine model of ligature-induced PD. Animals were randomized to study treatment (n = 3) (two applications 28 days apart) or control (n = 3). Laboratory results were normal throughout the study. Radiographs demonstrated increase in furcation bone density in all treated animals by 28 days after first treatment, which continued following the second treatment. Control animals showed continued loss of bone or minimal regeneration. Quantitative CT showed treated animals had 37% greater furcation bone volume, 18% greater bone mineral density and 21% greater bone volume to tissue volume ratio compared to control. As a proof-of-concept evaluation with limited sample size, findings provide the first direct evidence that a degradable, piezo-based hydrogel is efficacious for PD treatment in large animals and can inform future, larger-scale studies. The ability of Ambrilux to promote bone growth in tooth furcations suggests it could be a safe and novel approach to PD.

Gels doi: 10.3390/gels12111006

Authors: Mingwei Cao Chang Liu Tiantian Wang Yongyao Wei Xiongwei Liu Yuan Yuan Yuxin Pang

Bacterial wound infections remain a significant clinical challenge, requiring dressings that simultaneously provide durable antibacterial activity and controlled drug release. In this study, Blumea balsamifera (L.) DC. residue was upcycled into a cellulose-based hydrogel (BBR-CH), and its potential as a drug delivery platform was assessed using total flavonoids (BFTs) derived from the same plant as a model drug. The resulting BFT@BBR-CH hydrogel exhibited pH-responsive, first-order sustained drug release kinetics, potent antibacterial activity against Staphylococcus aureus, strong antioxidant capacity (IC50 = 0.056 mg/mL), and cytocompatibility exceeding 90%. In infected full-thickness rat wounds, BFT@BBR-CH achieved more than 94% wound closure by day 14, accompanied by enhanced collagen deposition and reduced inflammation. Mechanistically, BFT@BBR-CH downregulated TNF-α, IL-6, and IL-1β, while modulating EGFR/AKT1/HIF-1α/VEGF-A signaling and inhibiting FOXO3/Caspase-3-mediated apoptosis. Collectively, this work establishes BBR-CH as a sustainable and versatile drug delivery platform, providing a waste-to-wealth strategy for the development of advanced wound care materials.

Gels doi: 10.3390/gels12111005

Authors: William J. Peveler Shirin Alexander Wafaa Al-Shatty P. Stephen Patrick Jeremy K. Cockcroft Hollie Packman Sarah Rogers Cecile A. Dreiss Joseph C. Bear

This article describes the discovery, characterization and application of a small family of urea-based low molecular weight organogelators (LMWOs), namely the para-, meta- and ortho-1-dodecyl-3-(tolyl) ureas. All three LMWOs were tested for their ability to gel both polar and non-polar solvents and their properties were compared, with 1-dodecyl-3-(o-tolyl) urea proving the most versatile. 1-dodecyl-3-(o-tolyl) urea successfully gelled 1-octadecene, dimethylsulfoxide, petroleum ether, cyclohexane and toluene, with the latter gelling at just 0.8 wt.% of LMWO, making it a supergelator. The ability to gel both polar and non-polar solvents is an interesting and unusual property exhibited by few LMWO molecules, and as such, the applications for this molecule move beyond typical applications such as oil-spill remediation, into the biomedical and cosmetics sphere. Gels were characterized using rheology, small-angle neutron scattering (SANS), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Applications of 1-dodecyl-3-(o-tolyl) urea gels of dimethyl sulfoxide demonstrated in this study include in vitro release into an aqueous medium and bioimaging agent delivery.

Gels doi: 10.3390/gels12111004

Authors: Claire J. Wang Emilie A. Moses Joseph Collins Akmal Z. Umarov Dimitri A. Ivanov Andrey V. Dobrynin Sergei S. Sheiko

The elasticity of polymer networks is governed by the connectivity of load-bearing strands, yet their topology, fixed during synthesis, cannot generally be inferred from the nominal formulation. Structural parameters of the as-prepared network, including strand degree of polymerization, crosslink functionalities, loops, dangling structures, and other defects, depend on the synthesis history. Here, we demonstrate that nonlinear mechanical response can be used as a forensic probe for decoding this hidden network structure and detecting flaws in synthesis. We apply the forensics methodology to poly(n-butyl acrylate) bottlebrush networks prepared in independent synthetic trials using nominally identical formulations. Analysis of the structural modulus and strain-stiffening parameter obtained from nonlinear deformation determines whether a series of networks possesses a self-similar topology and differs primarily in crosslink density. For self-similar networks, the forensics framework provides the actual degree of polymerization between crosslinks, the topology coefficient of the load-bearing strands, and the contribution of non-load-bearing strands. Independent synthetic trials reveal that nominally identical formulations and synthetic protocols may either reproduce the same topological scaling or generate distinctly different network structures. These results establish network forensics as a characterization method that connects nonlinear mechanical response to network topology and provides quantitative feedback for refining network synthesis.

Gels doi: 10.3390/gels12111003

Authors: Guojun Li Meilong Fu Tengfei Chen Yuhao Zhu

A crosslinked hydroxypropyl guar (HPG) aqueous gel was investigated as the continuous, structure-forming phase of a CO2-rich mixed-phase fracturing fluid for unconventional gas reservoirs. The CO2 fraction was first screened by fluid-loss tests, after which the 30%, 40%, and 50% formulations were compared through proppant-settling tests. Although the 30% formulation exhibited the lowest cumulative fluid loss, the 40% formulation showed the lowest proppant-settling velocity and was selected for subsequent evaluation of phase behavior, gel-phase rheology, flow resistance, interfacial stabilization, and true-triaxial fracturing performance. Stable mixed-phase structures were maintained at 20–80 °C and 10–20 MPa, while bubble characteristics, rheology, and pipe-flow resistance showed a distinct response near 40 °C. Comparison with previously reported AM/AA–CO2 visualization showed that different water-soluble polymers generated different structures after CO2 mixing. Newly measured surface-tension and viscoelastic data, together with molecular dynamics simulations, indicated that bulk gel rheology alone could not account for this difference. HPG exhibited pronounced enrichment near the CO2–water interfaces, whereas AM/AA remained predominantly within the aqueous phase. Combined with the component-removal and viscoelasticity results, these findings suggest that HPG-specific interfacial behavior contributes to the formation and organization of dispersed structures, while the crosslinked gel network provides additional bulk viscoelastic support.

Gels doi: 10.3390/gels12111002

Authors: Zhiyi Lyu Hao Yang Yanjin Tang Hoo-Jeong Lee

Cellulose-based gels are emerging as promising soft materials for tactile electronic skin (e-skin) because of their tunable network structures, mechanical compliance, sustainability, and compatibility with ionic and electronic conduction. This review examines recent progress from material and structural engineering to tactile sensing, machine learning (ML)-assisted signal interpretation, and robotic manipulation. Particular attention is given to regenerated cellulose, nanocellulose, bacterial cellulose (BC), and carboxymethyl cellulose (CMC) systems, together with hierarchical porosity, anisotropic architectures, conductive fillers, and interfacial design strategies that improve sensitivity, sensing range, response speed, and mechanical stability. Representative demonstrations of wearable sensing, spatial pressure mapping, multimodal tactile acquisition, and sensor array integration are summarized and compared. The review further discusses how ML methods can extract task-relevant information from nonlinear and multimodal gel sensor signals, including handwriting, motion, material, texture, and object recognition. Studies on non-cellulosic hydrogel e-skin systems are included where they provide transferable approaches for tactile reconstruction, robotic integration, slip detection, and feedback control. Current evidence supports cellulose-based gels for soft tactile sensing, whereas transferable ML interpretation and robust robot-mounted, closed-loop manipulation remain less extensively validated. Future progress will require closer integration of material design, independent data validation, multimodal sensing, environmental stability, and task-specific robotic evaluation.

Gels doi: 10.3390/gels12111001

Authors: Mohammad Hadi Norahan Polina Koteneva Frederico David Alencar de Sena Pereira Anastasia Shpichka Polina Bikmulina Peter Timashev

3D bioprinting has evolved from developing simple cellular constructs to fabricating intricate, physiologically relevant tissue models. However, translation is bottlenecked by high equipment costs and processing trade-offs. This narrative review evaluates cost-effective engineering strategies over the past five years designed to enhance printing fidelity independently of material-chemistry innovations. Our observation reveals that thermal stabilization (2–60 °C) and static mixing elements yield resolutions down to 15 µm from cell-friendly 1 mm nozzles, while automated nozzle arrays accelerate spheroid processing 10 times. In-flow microfluidic gelation and self-healing granular baths eliminate architectural collapse, successfully preserving blood-vessel lumens (~50 µm). Additionally, newly developed procedural strategies significantly optimize output: nozzle-free painting and delayed-mixing droplet collision bypass clogging limits to handle ultra-dense networks, while vat-free projection methods reduce bioink waste to under 1%. These affordable modifications consistently preserve high post-printing cell viability (>90%) across complex, heterogeneous configurations. Ultimately, we conclude that the future of biofabrication relies on a transition toward closed-loop, AI-driven parameter optimization and the systematic integration of bioprinting platforms with active bioreactors to guide early structural constructs into functional, mature tissues.

Gels doi: 10.3390/gels12111000

Authors: Yang Luo Yaru Chi Zixuan Wang

Flexible hydrogel sensors hold great promise in wearable electronics, smart healthcare, and human–machine interfaces, yet their practical applications are often hindered by poor mechanical robustness, insufficient low-temperature tolerance, lack of self-healing ability, and inferior biocompatibility. Herein, we present a multifunctional ionic hydrogel composed of poly (acrylic acid), L-lysine, and aluminum ions (PAA-Lys-Al3+) for high-performance flexible strain sensors. Benefiting from its supramolecular network structure, the hydrogel exhibits efficient self-healing behavior and favorable antibacterial activity, as well as good biocompatibility. Impressively, the gel maintains stable gel-like properties even at −10 °C, overcoming the typical freezing-induced embrittlement of conventional hydrogels. When assembled into a flexible ionic sensor, the PAA-Lys-Al3+ hydrogel delivers high sensitivity, fast response, and reliable signal output toward various mechanical deformations. This integrated combination of antifreeze-resistant, self-healing, tough, elastic, antibacterial, and biocompatible features makes the hydrogel highly competitive in flexible sensing devices operated under harsh environments and biomedical scenarios.

Gels doi: 10.3390/gels12110999

Authors: Qiuli Cheng Zhiying Li Mengyao Guo Jialin Chen Leitao Zhang Wenlan Wu Ravin Narain Junbo Li

Wound dressings capable of conforming to irregular wound surfaces, withstanding mechanical deformation, and visually monitoring local microenvironmental changes are highly desirable for infected wound management. Herein, a versatile composite hydrogel (PFPU/VCM/BTB) based on the selected PFPU3 formulation was developed for the visual monitoring and treatment of infected wounds. The hydrogel was constructed from aldehyde-functionalized Pluronic F-127 (PF127-(CHO)2) micelles and a multifunctional PMUA copolymer containing primary amine groups, phosphorylcholine units, and 2-ureido-4[1H]-pyrimidinone (UPy) motifs. Reversible imine bonds and UPy-mediated quadruple hydrogen bonds generated the dynamic network, whereas bromothymol blue (BTB) and vancomycin (VCM) supplied pH-responsive visual detection and antibacterial activity, respectively. The resulting hydrogel exhibited porous morphology, solid-like rheological behavior, self-healing capability, tissue adhesion, and injectability. It displayed visible color changes within the pH range of 5.8–7.4 and effectively reduced Staphylococcus aureus (S. aureus) viability. In addition, the hydrogel showed good cytocompatibility and hemocompatibility and promoted fibroblast migration. In a full-thickness infected skin wound model, the hydrogel treatment reduced residual wound area, enhanced epidermal regeneration, and promoted collagen deposition by day 12. This multifunctional hydrogel integrates visual monitoring and localizes antibacterial functions within a single dressing platform, providing a potential approach for infected wound management.

Gels doi: 10.3390/gels12110998

Authors: Jie Liu Yongjie Li Jiaqi Yan Zishuai Chen Yanan Dai Zhixian Shen Guojun Xu Zifan Wang Zhiqiang Li

Introducing reversible covalent linkages, such as Schiff base bonds and disulfide bonds, into natural polymer networks like chitosan and hyaluronic acid has become an important research direction in the hydrogel field. This strategy seeks to reconcile the limited strength of physically crosslinked gels with the poor adaptability of permanently crosslinked gels. Although dynamic covalent networks, self-healing natural-polymer hydrogels, and injectable oral or periodontal materials have each been reviewed, these topics are often treated separately. The unresolved question addressed here is how to select dynamic bonds and regulate their exchange kinetics under the coupled constraints of the oral cavity, including salivary washout, masticatory friction, local pH/ROS/glucose fluctuations, required retention and degradation periods, and manufacturability. This review therefore focuses on dynamic covalent-crosslinked hydrogels built from natural polymer backbones and evaluates three mainstream bond types: Schiff base bonds, disulfide bonds, and boronic ester bonds. Following an oral-specific design framework of “pathological signals—bond response—property trade-offs—scenario fit—translation bottlenecks”, it examines local drug delivery and tissue-repair applications in periodontitis and oral ulcers and discusses dentin hypersensitivity and pulp protection only as potential extension directions. Diagnostic sensing, molecular imaging, and receptor-mediated targeting are outside the evidence base of this review and are not claimed as established applications. The review summarizes trade-off rules between mechanical performance and dynamic functions and identifies bottlenecks in multi-network regulation, sterilization, and clinical translation. Its added value lies in linking bond chemistry to oral-specific design constraints, rather than cataloguing hydrogel examples alone.

Gels doi: 10.3390/gels12110997

Authors: Laura Di Muzio Giovanni De Bellis Stefania Cesa Maria Antonietta Casadei Stefania Petralito Patrizia Paolicelli

Gelatin methacryloyl (GelMA) is the most widely used biomaterial for extrusion-based bioprinting. However, its intrinsic rheological properties often require optimisation with rheological modifiers, such as the nanoclay Laponite (Lapo). Since the rheological behaviour of GelMA/Lapo hybrid bioinks depends on polymer–nanoclay interactions, the physicochemical and conformational properties of GelMA are expected to critically influence Lapo incorporation, the resulting rheological behaviour, and ultimately printability. Accordingly, this study combines formulation design with a systematic rheology-guided screening strategy. Two GelMA derivatives (GelMADP and GelMASP) obtained through different synthesis procedures, and characterised by distinct physicochemical and structural properties, were used to prepare GelMA/Lapo bioinks under physiologically relevant conditions. GelMASP enabled homogeneous incorporation of higher Lapo contents than GelMADP, expanding the formulation space and allowing the development of hybrid inks with improved rheological properties. A sequential rheological roadmap integrating oscillation temperature-ramp, flow-sweep, yield stress, and elastic recovery analyses was then used to progressively screen the formulations and guide the selection of suitable processing conditions. Among the investigated formulations, SP20-3 (20% w/v GelMASP and 3% w/v Lapo) exhibited the most suitable rheological profile, combining favourable temperature-dependent gelation, pronounced shear-thinning behaviour, and rapid structural recovery, ultimately leading to high printing fidelity. These properties were largely retained also after high-density cell inclusion. Overall, these results identify the physicochemical and conformational properties of the starting GelMA as critical design parameters governing polymer–clay network organisation, rheological behaviour, and bioink printability, while highlighting the value of a systematic rheology-guided approach for formulation screening and optimisation.

Gels doi: 10.3390/gels12110996

Authors: Chongchong Wang Zhihua Li Weihong Min

This study evaluated how Polygonatum processing affected its functional components, steamed bread quality, and gluten protein structure. Four-cycle extruded Polygonatum (EP-4) significantly enhanced antioxidant activity compared with raw Polygonatum (RP) and improved polysaccharides, flavonoids, and water-soluble extractives retention by 7.56%, 356.62%, and 8.15%, respectively, compared with nine cycles of steaming and sun drying Polygonatum (NP). RP, EP-4, and NP increased steamed bread antioxidant activity in the order NP > EP-4 > RP > control. However, all treatments increased hardness and chewiness while decreasing springiness and cohesiveness. The results suggested that RP limited protein aggregation, potentially through water competition and steric hindrance, whereas EP-4 promoted protein cross-linking, increasing dough stability time by 13.61% at 12% addition. NP showed signs of enhanced protein aggregation, reducing dough stability time by 39.92% and increasing adhesiveness 3.08-fold. SDS-PAGE and SDS-extractable protein analyses showed stronger low-molecular-weight bands and higher SDS-extractable protein content in RP, and band intensity partial recovery under reducing conditions in EP-4. Reduced SDS extractability at higher NP levels was consistent with increased protein aggregation. Overall, Polygonatum affected steamed bread quality via gluten aggregation, and EP-4 generally caused less deterioration than RP and NP.

Gels doi: 10.3390/gels12110995

Authors: Maria Demeter Ion Cosmin Călina Anca Scărișoreanu Andreea Mariana Negrescu Anișoara Cimpean Florin Bîlea Marin Micutz Mădălina Albu Kaya

This study validates a multicomponent collagen/CMCNa/PVP/PEO hydrogel, synthesized via e-beam crosslinking at 25 kGy for localized doxorubicin (DOX) delivery. Fabrication reproducibility, drug stability, loading efficiency, and preliminary in vitro biological activity were investigated. Batch-to-batch reproducibility was demonstrated across three independent preparations. Three independent preparations showed reproducible gel fractions (90.4–94.0%), equilibrium swelling (1550–1950% at pH 6.4 and 1600–1850% at pH 7.4), and predominantly elastic behavior (tg δ = 0.014–0.03). Long-term degradation testing confirmed structural integrity, with only 8.24% mass loss after 84 days in physiological conditions. LC-MS analysis revealed considerable DOX degradation post-irradiation, supporting the adoption of a diffusion-based post-loading approach. The DOX-diffusion-loaded hydrogels exhibited high loading efficiency (>72%) and a loading capacity of ~3.88 µg/g. In vitro, the hydrogels provided biphasic yet sustained, diffusion-controlled DOX release (60–68% over 58 h pH-dependent). Biological assays showed concentration-dependent cytotoxicity of free DOX against A375 melanoma cells (IC50 = 0.038 µg/mL), while directly irradiated DOX-loaded hydrogels (H-DOX) at low exposure concentrations demonstrated cytocompatibility with VERO epithelial and CCD-1070Sk fibroblast cells, and a moderate, time-dependent antiproliferative effect on A375 cells. Collectively, these results establish crosslinked hydrogels with post-loading as a reproducible, stable, and cytocompatible platform for localized DOX delivery, highlighting their potential for adjuvant melanoma therapy.

Gels doi: 10.3390/gels12110993

Authors: Marzia Cirri Riccardo Mattagli Elena Pieri Silvia Fiani Natascia Mennini Francesca Maestrelli Letizia Gai Paola A. Mura

Severe oral mucositis requires local treatments that relieve pain, limit microbial proliferation, and support mucosal repair while minimizing exposure to potentially harmful excipients, particularly in pediatric patients. This study aimed to develop thermosensitive mucoadhesive gels co-loaded with lidocaine hydrochloride (2% w/v) and chlorhexidine digluconate (0.2% w/v) for localized buccal therapy. Poloxamer 407 was combined with hyaluronic acid sodium salt, xanthan gum, Carbopol 934, or hydroxypropylmethylcellulose (HPMC). Formulations containing lidocaine alone or both drugs were compared to assess the influence of chlorhexidine addition. Following preliminary screening based on pH and gelation properties, selected formulations were characterized for technological, mucoadhesive, biopharmaceutical, stability, and antibacterial properties. Poloxamer 407 concentration was the main factor governing gel performance, whereas the mucoadhesive polymer primarily affected specific technological attributes. Chlorhexidine incorporation did not compromise overall gel performance, preserving antibacterial activity. The gels exhibited suitable gelation, spreadability, mucoadhesion, residence time, and release properties with negligible membrane permeation. The dual-drug formulation containing 20% poloxamer 407 and 0.50% HPMC emerged as the most promising one, combining appropriate mechanical properties, drug release, antibacterial efficacy, and storage stability. Overall, these findings support dual-drug thermosensitive mucoadhesive gels as a feasible strategy for the local management of severe oral mucositis, especially in pediatrics.

Gels doi: 10.3390/gels12110994

Authors: Kamala Asgarova İrem Toprakçı Rabia Nur Bozkurt Ebru Kurtulbaş Barış Çağatay Selin Şahin

Alginate microparticles offer a simple approach for drug encapsulation. However, their performance depends on formulation conditions. Diclofenac sodium (DCF) was encapsulated in alginate microparticles by ionic gelation. Sodium alginate concentration, CaCl2 concentration and hardening time were optimized by Response Surface Method (RSM) using Box–Behnken design (RSM-BBD). Encapsulation efficiency (EE) varied considerably with the formulation conditions. The model showed a good fit (R2 = 0.9685), while CaCl2 concentration was the main factor affecting EE. The optimum conditions were 1.91% (w/v) sodium alginate, 4.99% (w/v) CaCl2 and 23.4 min hardening time. The experimental EE was 80.34%, close to the predicted value of 80.41%. Chitosan was added to the optimized formulation at concentrations of 0.10–0.20% (w/v). EE increased with chitosan concentration and reached 93.85% at 0.20%. Drug release was studied in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The release data were evaluated using zero-order, first-order, Higuchi and Korsmeyer–Peppas models. Characterization revealed a transition from a predominantly lamellar and fissured surface in the optimized alginate formulation to a more granular and highly textured architecture following chitosan incorporation, while the released fractions exhibited distinct hydrodynamic and electrokinetic characteristics. The addition of a low amount of chitosan therefore increased DCF encapsulation and changed its release behavior under gastrointestinal conditions.

Gels doi: 10.3390/gels12110992

Authors: Guodong Zhang Fangli Gang Xiao Meng Xiaoyao Yang Wenhui Chai Yanhua Xin He Zhang

Hydrogel films, as emerging bio-based packaging materials, hold considerable promise for preserving perishable fruits such as strawberries. However, their application is limited by poor water retention, insufficient mechanical strength, and lack of antibacterial activity. In this study, gelatin was mixed with NaCl and then soaked in a glycerol/water binary solvent system to fabricate gelatin/glycerol/NaCl (GGN) hydrogels. Results showed that glycerol incorporation endowed the hydrogels with excellent anti-drying performance, attaining a residual mass ratio of 55% and a transmittance of 75% after 9 days. At 7.5% (w/w) NaCl, the hydrogel achieved a tensile strength of 110 kPa and an elongation at break of 250%, along with antibacterial rates of 75.60% against Staphylococcus aureus and 86.11% against Escherichia coli, respectively. Strawberry preservation tests demonstrated that the GGN hydrogel effectively reduced weight loss and maintained fruit quality over 8 days, outperforming the control and commercial PE film groups. Overall, this study presents a facile strategy for fabricating multifunctional gelatin-based hydrogel films, offering a viable alternative to petroleum-based plastics for perishable fruit preservation.

Gels doi: 10.3390/gels12110991

Authors: Guanghui Wu Yuyao Fang Junyong Chen Defang Pan Ziqi Zhu

Traditional silica aerogels suffer from inherent brittleness and insufficient mechanical properties, which severely restrict their large-scale applications in high-end thermal insulation and flame retardancy. Aiming at low-cost industrialization, we employ cost-effective sodium silicate as the silicon source and hexamethyldisilazane (HMDZ) as the hydrophobic modifier and innovatively introduce polyimide (PI) nanofibers to construct SiO2/PI composite aerogels. A unique luffa-sponge “seed (dispersed phase)–vein (connecting phase)” topological structure is realized. The interwoven PI nanofibers form a continuous and tough 3D network, which immobilizes SiO2 particles, restrains slippage and agglomeration, and transfers stress through strong interfacial interactions, thereby fundamentally overcoming the brittleness of silica aerogels. The optimized composite aerogel shows a thermal conductivity as low as 26.20 mW/(m·K) and a compressive strength of 21.62 MPa at 70% strain. Meanwhile, it exhibits superhydrophobicity with a water contact angle of 151° and remarkable self-extinguishing behavior. This work provides a low-cost strategy to integrate topology design and multifunctionality, realizing the combination of ultra-low thermal conductivity, high mechanical robustness, superhydrophobicity, and excellent flame retardancy in one aerogel. The as-prepared composite shows great potential in thermal insulation, flame retardancy, aerospace, and new energy applications.

Gels doi: 10.3390/gels12110990

Authors: Wenhui Wu Xiaona Gao Ying Xu Yanshen Li Yanli You Rentai Song Wenqing Chen Haiying Cui Lin Lin Yulin Zhu

The cold adaptation of Listeria monocytogenes (LM) makes it a major contaminant of refrigerated foods. This study explored the growth ability and adaptive mechanism of LM to low temperatures, focusing on histidine kinase LisK as a target and selecting carvacrol to interact with LisK to disrupt the cold adaptation of LM. Changes in gene expression and membrane phospholipids enabled LM to grow robustly under cold conditions. The knockout of the LisK gene verified its essential role in LM cold adaptation, supporting LisK as a plausible site of action. Carvacrol can form a stable structure with histidine kinase LisK through multiple interacting forces. Transcriptomic analysis identified 747 differentially expressed genes in LM after carvacrol treatment at low temperatures, with the two-component system pathway being significantly enriched. Carvacrol affected the growth ability of LM at low temperatures. In addition, the morphology, membrane permeability and intracellular macromolecules of LM at low temperatures were all impaired after carvacrol treatment. Finally, carvacrol inhibited the growth of LM and preserved the texture of pork meat gels stored at 4 °C. In conclusion, the above results confirmed the inhibitory effect of carvacrol on the growth of LM at low temperatures.

Gels doi: 10.3390/gels12110989

Authors: Yangnan Shangguan Lei Liu Junhong Jia Jinghua Wang Han Peng Tengfei Wang

Long-term water flooding in heterogeneous Changqing Oilfield reservoirs leaves substantial residual oil trapped in low- and ultra-low-permeability pores, where small pore throats, strong capillarity, and high seepage resistance restrict waterflood sweep efficiency and residual oil mobilization. To address the wide carbon-number distribution, strong low-permeability heterogeneity, and fracture-induced channeling in Block X of the Changqing Oilfield, we proposed a synergistic strategy combining interfacial modification and preferential-pathway regulation. We constructed a C14(PO)4SO3Na (TDS)-synergized microsphere–microgel system comprising the interfacial modifier TDS, microspheres, and microgel particles. Core flooding showed that TDS alone outperformed conventional surfactants (Cocamidopropyl betaine, CAB-35). In heterogeneous models, the microsphere/TDS system achieved 54.45% recovery; in fractured models, microgel showed better plugging and flow-diversion performance than microspheres. Using a 0.3 PV microgel pre-slug followed by a 0.7 PV microgel/TDS mixture, Model II reached 45.58% recovery, indicating that plugging preferential pathways before synergistic flooding is an optimal injection strategy. Microvisualization revealed that water flooding readily channeled through large pores, high-permeability pathways, and fractures. In micromodel experiments, the composite system increased areal sweep efficiency to 60.4%, 49.8%, and 66.4% for low-, high-, and ultra-low-permeability models, respectively. In comparison, core flooding gave recovery factors of 54.45% (heterogeneous matrix) and 45.58% (fractured Model II). Produced-fluid and core SEM results indicated that regulating particles migrated, were retained, bridged, and possibly re-migrated in pore throats, increasing flow resistance in preferential pathways and diverting subsequent fluids to unswept zones.

Gels doi: 10.3390/gels12110988

Authors: Nan Zhao Chao Liu Chao Zhu

Sulfate-bearing cyclic environments induce coupled degradation of hydration gels and pore structure, but the differences between freeze–thaw and wet–dry deterioration remain unclear. Nine fly ash–bentonite cementitious composites with fly ash-to-cement ratios of 1.2, 1.8, and 2.4 and bentonite contents of 0%, 3%, and 6% were exposed to water, 10% Na2SO4, and 10% MgSO4 for up to 150 cycles. Macroscopic durability was evaluated using the squared ultrasonic pulse-velocity index (plotted as apparent RDEM), compressive-strength retention, and peak-stress retention; hydration products and pore evolution were characterized by X-ray diffraction, scanning electron microscopy, and low-field nuclear magnetic resonance. Freeze–thaw cycling was mainly associated with physical cracking and a redistribution toward longer-T2 water-accessible relaxation components, whereas wet–dry cycling intensified salt crystallization and sulfate-product accumulation. Sodium sulfate exposure was associated with stronger ettringite and gypsum diffraction peaks, whereas magnesium sulfate exposure showed a stronger gypsum peak and a weaker portlandite peak. Among the tested complete formulations, moderate fly ash contents and low bentonite dosages (with corresponding water-reducer adjustments) provided the most balanced resistance, whereas FA/C = 2.4 with 6% bentonite generally deteriorated more rapidly. Based on pooled out-of-fold predictions, support vector regression performed best for the apparent RDEM indicator (R2 = 0.929), while random forest gave the highest accuracy for compressive-strength retention (R2 = 0.937) and peak-stress retention (R2 = 0.994); the first two targets had 378 condition records each and peak stress had 216 author-confirmed numerical values. In leave-one-mixture-out sensitivity analysis, the corresponding pooled R2 values were 0.897, 0.942, and 0.992, respectively; this analysis assesses interpolation to an unobserved combination within the tested 3 × 3 composition grid, not extrapolation beyond its factor levels. Recomputed grouped SHAP attribution identified cycle count as the leading input for apparent RDEM (44.94% of relative mean absolute attribution), while the exposure-regime input dominated strength retention (53.36%) and peak-stress retention (56.65%); cycle count × regime was the strongest pairwise interaction in both mechanical targets. At limit states of 60% RDEM and 75% compressive-strength retention, the predicted durability thresholds ranged from 17 to more than 150 cycles, with RDEM governing most cases. The proposed framework pairs crystalline-phase and pore-structure observations with interpretable durability prediction within the tested cyclic sulfate environments. These are exploratory laboratory-cycle thresholds. A 300-resample trajectory bootstrap quantified model-refit variation; neither the thresholds nor their intervals are calibrated to field service time.

Gels doi: 10.3390/gels12110987

Authors: Francisco Flores-Céspedes Luis García-Fuentes

Hybrid alginate hydrogels offer a versatile platform for integrating the structural properties of biopolymeric networks with the functionality of inorganic and biomass-derived fillers. In this study, calcium-alginate hydrogels incorporating thermally treated bentonite, olive pomace, or kraft lignin were prepared by ionotropic gelation to investigate how filler identity influences hydrogel properties and Rhodamine B (RhB) adsorption. The hybrid materials were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area analysis, and determination of the point of zero charge (pHpzc). Their adsorption behavior was evaluated through kinetic, equilibrium, pH, ionic-strength, and regeneration studies. Despite the very low N2-accessible surface areas measured in the dry state, the hydrogels exhibited markedly different adsorption performances, indicating that dry-state BET surface area alone does not account for RhB uptake and highlighting the importance of filler chemistry, surface-charge characteristics, and the accessibility of adsorption domains within the hydrated network. Adsorption kinetics were better described by the pseudo-second-order model, while intraparticle diffusion analysis indicated a multistep mass-transfer process. Equilibrium data were empirically well described by the Langmuir model, with fitted maximum adsorption capacities ranging from 12.4 to 212.7 mg·g−1. Bentonite-containing hydrogels exhibited the highest capacities, following the order AB110 > AB200 > AB400. Increasing the bentonite thermal-treatment temperature decreased the fitted maximum adsorption capacity while increasing the Langmuir affinity parameter, revealing a capacity–affinity trade-off. The lignocellulosic fillers produced lower-capacity adsorption systems with distinct apparent affinities and responses to solution conditions. After five adsorption–desorption cycles, the bentonite- and lignin-containing hydrogels retained more than 80% of their initial adsorption performance, whereas the olive-pomace-containing formulations retained approximately 70%. Overall, the results demonstrate that incorporating chemically distinct mineral and lignocellulosic fillers into a common calcium-alginate network provides an effective strategy for tuning the structure–property–adsorption relationships and reusability of hybrid hydrogels, supporting their further development as sustainable adsorbent materials for water-remediation applications.

Gels doi: 10.3390/gels12110986

Authors: Marcos Flores-García Vilma Quitral Verónica Olate-Olave Carolina Barros Roberto Quiroz Cristian Valdés Yaneris Mirabal Jaime Ortiz-Viedma

Oleogelation represents a promising strategy for enhancing the functional and thermal properties of edible oils. This study evaluated the structural protection mechanism of an extra virgin olive oil (EVOO) oleogel, structured with 6% (w/w) beeswax, subjected to prolonged discontinuous deep-frying cycles compared to unstructured EVOO. Degradation kinetics were monitored through total polar compounds (TPCs), acid value, UV absorption, p-anisidine value, and FTIR-ATR spectroscopy. Structural integrity was evaluated via Texture Profile Analysis (TPA), and the thermal trajectory was modeled using Principal Component Analysis (PCA). The results explicitly demonstrate a two-stage kinetic behavior. During the initial phase (Days 1–3), the three-dimensional crystalline network acted as a steric confinement barrier, restricting molecular mobility and oxygen diffusion. This significantly delayed the formation of primary and secondary oxidation products, maintaining TPC and acidity markedly lower than the EVOO control. However, continuous thermal stress induced acute thermomechanical fatigue. By Day 4, the oleogel underwent severe structural collapse—evidenced by a 67% loss in hardness—which abolished the physical barrier and caused the degradation kinetics to accelerate, ultimately converging with those of the unstructured oil. These findings reveal that while beeswax oleogelation substantially boosts initial thermo-oxidative stability, its finite mechanical resistance limits its operational lifespan. Understanding this structural collapse is crucial for engineering more resilient, functionally tailored lipid matrices for high-temperature food applications.

Gels doi: 10.3390/gels12110985

Authors: Qing Lin Limin He Kaimin Su Jianbiao Zhang Liuyi Dong Yun He Huiren Xu

Olivine-type LiFePO4 is a promising cathode candidate for lithium-ion batteries. In this study, undoped and a series of Co-substituted LixCoᵧFePO4 (x = 0.85–1.00, y = 0–0.15) nanocomposites were synthesised by sol–gel auto-combustion using organic–inorganic hybrid xerogel precursors. The effects of sol pH, calcination temperature, calcination holding time and Co2+-doping content on crystal structure, phase composition, crystallinity, particle morphology, magnetic-hysteresis performance and Fe valence-state distribution were systematically explored using TG-DTA, XRD, FT-IR, SEM, VSM and Mössbauer spectroscopy. XRD analyses reveal that intermediate-pH conditions (pH 6.5–7.5) readily produce crystalline impurities including LiFeO2 and Fe2O3, whereas high-pH environments (pH 8.5–9.5) facilitate the formation of pure-phase olivine-structured products. Diffraction-peak sharpness increases with rising calcination temperature, indicating improved crystallinity, and the samples treated at 800 °C exhibit the sharpest diffraction signals. As the doping level increases, the (311) diffraction peak first shifts toward lower and then higher angles; correspondingly, the unit-cell volume first increases to a maximum and then declines, whereas the crystallite size varies non-monotonically, confirming that Co doping predominantly modifies the lattice geometry. For the heavily doped Li0.85Co0.15FePO4, carbothermal reduction induced by excessive thermal treatment (T > 700 °C or extended holding) yields a secondary phosphide phase that is tentatively indexed as Co2P from two weak reflections. Within the Co-substituted series, the 700 °C—10 h condition gives a single-phase product with the highest saturation magnetisation (Ms = 3.45 emu·g−1), which decreases to 2.07 emu·g−1 at 800 °C. VSM results demonstrate a decoupling between the saturation magnetisation (Ms) and the coercivity (Hc); the weak ferromagnetic hysteresis observed in all samples signals trace ferromagnetic secondary phases—most plausibly amorphous or nanoscale products of xerogel thermal decomposition that lie below the XRD detection limit—rather than indicating phase purity; this attribution is indirect and is critically assessed below. Mössbauer spectroscopy validates the coexistence of dominant high-spin Fe2+ and minor Fe3+ species within the samples. High-level Co substitution (y = 0.15) lowers the relative proportion of the Fe3+ impurity species to 7.2% and alters the local Fe coordination environments without generating magnetically ordered sextet components. This work demonstrates that the sol–gel-derived hybrid xerogel is a tunable platform for fabricating phosphate-based battery nanocomposites and provides insights for the gel-precursor-directed design of energy-storage functional materials.

Gels doi: 10.3390/gels12110984

Authors: Taehee Kim Haryeong Choi

Electrochemical nitrate reduction can combine nitrogen removal with ammonia recovery, but the contribution of an aerogel network is difficult to separate from changes in catalyst chemistry and electrode preparation. This review examines when the architecture created by gelation and drying remains relevant after electrode fabrication and during nitrate conversion. Metallic, carbon-based, and hybrid aerogels are compared through their preparation, working-state structure, reaction evidence, and operating conditions. Particular attention is given to nitrate activation, downstream hydrogenation, soluble-intermediate retention, and competition with hydrogen evolution and nitrogen formation. Related non-aerogel studies provide mechanistic and reactor comparisons while retaining their distinct material identities. The analysis separates measured responses from proposed pathways and distinguishes peak Faradaic efficiency from sustained conversion and product recovery. Dry surface area, isolated spectroscopic signals, and performance measured under different conditions do not independently establish an aerogel-specific advantage. Priorities emerging from the literature are comparisons of retained and fragmented networks, coupled measurements of intermediate transport and catalyst reconstruction, and nitrogen balances under defined feed and recovery conditions. These comparisons provide a basis for evaluating which aerogel design features remain useful in a working nitrate-conversion device.

Gels doi: 10.3390/gels12110983

Authors: Silvia Panzavolta Maria Cristina Cassani Isacco Gualandi Barbara Ballarin

Conductive hydrogels have emerged as promising materials for wearable electronics owing to their combination of mechanical flexibility, high water content, and electrical responsiveness. However, achieving a suitable balance among conductivity, mechanical robustness, and electromechanical sensitivity remains challenging. Herein, we report a physically crosslinked poly(vinyl alcohol) (PVA) hydrogel incorporating zirconium fumarate metal–organic framework (Zr-MOF-801) particles functionalized through in situ polymerization of polyaniline (PANI), yielding a MOF-PANI hybrid filler. Incorporation of MOF-PANI increased the apparent bulk conductivity of the hydrogel while preserving its flexibility and structural integrity. Mechanical characterization revealed a marked change in the response of the materials above approximately 60% strain. Simultaneous tensile and chronoamperometric measurements showed clearly different strain-dependent electrical responses for the pristine Hydro, Hydro/MOF, and Hydro/MOF-PANI formulations. The pristine hydrogel exhibited negative ΔR/R0 values during stretching, whereas both MOF-containing systems showed positive resistance variations. PANI functionalization further increased the response magnitude and improved short-term cyclic reproducibility. The Hydro/MOF-PANI hydrogel exhibited an apparent bulk conductivity of approximately 7.0 × 10−3 S cm−1 and an approximately linear electromechanical response over the investigated 20–110% strain range, with an apparent strain sensitivity of about 2.2. The observed differences among the three formulations are consistent with filler-induced changes in the overall transport network; however, the specific microscopic contributions of ionic transport, polymer–particle interfaces, and PANI-containing conductive regions cannot be directly resolved from the present measurements. Finally, integration of Hydro/MOF-PANI into an elastic knee brace enabled proof-of-concept detection of repeated knee flexion–extension movements. These results identify MOF-PANI/PVA hydrogels as a promising platform for strain-responsive soft materials and wearable motion sensing, while further studies are required to establish long-term durability, rate dependence, hydration stability, and quantitative wearable calibration.

Gels doi: 10.3390/gels12110982

Authors: Jianxun Meng Xiangbin Liu Qingsong Li Zhixuan Zhu Guoliang Mao Qingguo Wang Qi Zhou Baize Zhu Biao Zhang Xuesong Lin Lichao Wang

Conventional polymer gels for deep fluid diversion in moderate-temperature (40–60 °C) reservoirs are constrained by the chromatographic separation of crosslinkers and poor gelation controllability. In this work, a side-chain pendant decoupling molecular design strategy is proposed. Using cardanol glycidyl ether, diethylenetriamine (DETA), and polyethylene glycol diglycidyl ether (PEGO), a stepwise route exploits the differential reactivity of mono- versus di-epoxide groups to graft cardanol C15 alkyl chains as freely pendant side groups onto a PEGO/DETA covalent network. The covalent network provides a mechanical skeleton, while the pendant C15 chains act as independent thermoresponsive switches, liberating the C15 chains from topological constraints. This endows the hydrogel with a clear thermoresponsive transition around 40 °C, with G′ increasing to 980 Pa and the transmittance dropping from 28.9% to below 4%. Kinetic analysis indicated a transition from diffusion-controlled to chemically controlled network growth. The Avrami exponent n ranged from 0.85 to 1.28 across the tested temperatures. The poor linearity of the Arrhenius fits (R2 = 0.62 and 0.35) indicates non-Arrhenius behavior, consistent with the proposed synergistic dual mechanism. Given the unavoidable salinity of formation water in actual reservoirs, the effect of salinity on gelation kinetics was further examined. At 45 °C, varying the NaCl concentration from 0 to 5000 mg/L affected gelation kinetics, while the measured plateau storage moduli remained similar under the investigated conditions. Physical simulation experiments showed a plugging rate of 96.1% at 60 °C in deionized water, and in situ gelation in the core under simulated reservoir brine led to a 99.98% permeability reduction within 60 min. This cardanol-derived hydrogel with engineered side chains establishes a molecular engineering principle in which pendant grafting liberates hydrophobic chains from topological constraints, offering a new paradigm for cardanol-derived intelligent oilfield chemicals in deep reservoir conformance control.

Gels doi: 10.3390/gels12110981

Authors: Lifen Liang Yuekun Mi Xiaolu Zhang Chaoyuan Chai Xinyu Feng Yuhang Liu Wei Liu Jun Guo Feng Cui

Hydrophobic essential oils are difficult to incorporate uniformly into hydrophilic polymer matrices. This study compared a citrus essential oil (CEO) microemulsion-based formulation series (CEO-M) with a coarse-emulsion series (CEO-C) at nominal CEO concentrations of 20–100 mg mL−1 in poly(vinyl alcohol)/sodium alginate (PVA/SA) composite films. Because the two emulsion series differed in emulsifying-phase composition and preparation procedure, their effects were interpreted at the formulation level. Mechanical, optical, barrier, microstructural, and radical-scavenging properties were evaluated, and PVA-SA-60M was selected for further evaluation based on its overall property profile. After standardized 100-fold dilution with distilled water, CEO-60M exhibited a smaller hydrodynamic diameter, lower polydispersity index, and more negative ζ-potential than CEO-60C at a nominal CEO concentration of 60 mg mL−1. Targeted GC-FID analysis gave estimated limonene retentions of 57.0 ± 4.6% and 41.0 ± 3.4% in PVA-SA-60M and PVA-SA-60C, respectively. In a release-based film-disk assay, both CEO-containing films produced growth-inhibition zones against Penicillium expansum and Botrytis cinerea. During 8 days of storage at 4 °C, pork wrapped with PVA-SA-60M showed lower TBARS than both the unwrapped and neat PVA-SA film control treatments and lower TVC and TVB-N than the unwrapped control at later storage stages. Color measurements did not show an additional endpoint advantage over the neat PVA-SA film. These results support further evaluation of PVA-SA-60M as an active film formulation for chilled pork.

Gels doi: 10.3390/gels12110980

Authors: Joana Santos Fernando Mata Meirielly Jesus Joaquim Cerqueira José Araújo Gustavo Paixão

Gelatine is an established animal-derived gel-forming protein, but the European industrial context supporting its availability remains poorly quantified. Eurostat production, trade and Structural Business Statistics were integrated to characterise the EU-27 gelatine supply system during 2014–2024, with a separate 2025 trade update. Nominal sold-production value increased from EUR 1.021 to EUR 1.285 billion, whereas sold-production quantity showed no statistically significant linear trend. Apparent physical availability was approximately 167 kt in 2024 (rounding-base bounds: 137–197 kt), compared with 125.60 kt in 2014. Its positive trend over 2014–2024 (+1.79%/year, p = 0.029) was not statistically significant when restricted to 2017–2024 (+2.30%/year, p = 0.070), following the PRODCOM product-definition change. Extra-EU imports value more than doubled in nominal terms, accompanied by a 69.7% increase in imported quantity, while the normalised external trade balance declined from +0.471 to +0.221. In 2024, the five largest disclosed producers accounted for at least 75.4% of official EU-27 production value. In 2023, gelatine import value co-scaled with food-manufacturing turnover across Member States (Spearman ρ = 0.828; log–log β = 0.976, 95% CI 0.807–1.144), although this adjusted association may reflect overall country size. Within-country fixed-effects models showed no significant short-term association. A targeted 2020–2026 evidence map identified 35 experimental studies addressing packaging/coatings/preservation (n = 11), 3D printing/digital food (n = 9), emulsion/lipid structuring (n = 8), confectionery/gummies (n = 3), ingredient/source functionality (n = 2), dairy/yoghurt (n = 1) and meat/low-fat products (n = 1). These findings illustrate the diversity of contemporary experimental applications rather than their commercial prevalence or industrial gelatine consumption. After excluding two source-functionality studies, a research-weighted scenario allocated 2024 apparent availability across packaging/preservation (38.1%; 63.5 kt), emulsion/lipid structuring and 3D printing (19.0%; 31.7 kt each), confectionery (14.3%; 23.8 kt) and dairy and meat applications (4.8%; 7.9 kt each). These quantities are illustrative research-weighted equivalents, not observed market shares or consumption.

Gels doi: 10.3390/gels12110979

Authors: Paula Kristiāna Harpere Renāte Teterovska

Tanacetum vulgare L. (Common tansy) contains a high concentration of biologically active compounds, such as phenols, terpenes, and flavonoids, that act as anti-inflammatory, antimicrobial, and antioxidant agents. Hydrogel beads can be used to encapsulate these biologically active components to ensure their stability and targeted intestinal delivery. The aim of this preliminary study was to develop sodium alginate hydrogel beads incorporating lyophilized T. vulgare leaf extract in different concentrations and perform physicochemical and structural analyses to determine the possibility of further developing T. vulgare-containing hydrogels for targeted intestinal delivery of polyphenols. The development of 2% sodium alginate hydrogel beads using extrusion and ionic crosslinking with a 1.5% calcium chloride solution was successful. Beads presented amorphous, viscoelastic, non-thixotropic behaviour and hydrogen bonding with polyphenols from T. vulgare extract. Alginate crosslinking exceeded 78%. Encapsulation of chlorogenic acid equivalents (CGAEs) was on average 28.4% to 39.3%. Beads degraded in pH 6.8 and 7.4 within 24 h, releasing up to 80.1% of encapsulated CGAEs. The highest antiradical activity was 5.5% per gram of beads, with the half-maximal inhibitory concentration (IC50) of the T. vulgare extract being 250 μg/mL. This information can be used to further develop alginate hydrogel beads containing T. vulgare leaf extract.

Gels doi: 10.3390/gels12110978

Authors: Xinyue Yang Seongju Lee Sungwon Jung Sohyeon Park

Cultured meat has emerged as a promising alternative to conventional meat due to its potential to improve sustainability, animal welfare, and food supply stability. However, successful commercialization requires not only the efficient generation of muscle tissue but also the reproduction of the texture, sensory attributes, and nutritional value of conventional meat. To date, most studies have primarily focused on promoting cell adhesion, proliferation, and differentiation on scaffolds, while scaffold design strategies specifically aimed at achieving meat-like texture remain comparatively underexplored. This review provides a broad overview of scaffolds used in cultured meat production and summarizes recent advances in scaffold design strategies to enhance textural properties, with an emphasis on achieving texture and eating quality comparable to those of conventional meat.

Gels doi: 10.3390/gels12110977

Authors: Anca Daniela Raiciu Fawzia Sha’at Amalia Ștefaniu Mihaela-Carmen Eremia Ramona-Daniela Pavaloiu

This study investigated dermatocosmetic hydrogel formulations containing inulin and a quality-controlled organic Calendula officinalis L. flower extract in 20% propylene glycol, with emphasis on physicochemical and textural characterization. Seven formulations were prepared and evaluated for organoleptic characteristics, pH, firmness, cohesiveness, springiness, and resilience. All formulations were macroscopically homogeneous, while pH values ranged from 6.28 ± 0.01 to 6.66 ± 0.04. Texture Profile Analysis revealed formulation-dependent mechanical behaviour. Firmness ranged from 0.430 ± 0.002 to 0.698 ± 0.042 N, cohesiveness from 0.660 ± 0.009 to 0.874 ± 0.013, springiness from 0.778 ± 0.001 to 0.941 ± 0.037, and resilience from 0.277 ± 0.005 to 0.494 ± 0.016. One-way ANOVA indicated an overall formulation effect for all four texture parameters (p < 0.0001), followed by Tukey HSD pairwise comparisons. Gel 2, containing 2% inulin without Calendula officinalis extract, exhibited the highest numerical firmness and springiness, whereas Gel 5, containing 4% inulin and 3% Calendula officinalis extract, showed the highest cohesiveness and resilience. The extract-only Gel 6 displayed the lowest numerical values for all four texture parameters. The results support a formulation-dependent, non-linear effect of inulin on gel mechanical behaviour and provide a physicochemical basis for subsequent rheological, stability, phytochemical, release, safety, and biological investigations.

Gels doi: 10.3390/gels12110975

Authors: Shiting Shen Lin Du Wei Deng Wei Liu Yongjie Chen Liu He Xin Liu Pinghua Shu Songcai Han Lanxiao Hu

Hydrogels have been widely applied as plugging agents for profile control in oilfields due to their favorable swelling behavior, deformability, and pore-throat plugging ability. However, many hydrogels suffer from poor plugging performance due to hydrolysis and hardening under high-temperature and high-salinity conditions. In this study, a novel hydrogel designated as ADSI (A: acrylamide; D: divinylbenzene; S: vinyltrimethoxysilane; I: 1-vinylimidazole) is developed for high-temperature and high-salinity conditions. In this gel, polyacrylamide (PAAm) acts as the backbone, incorporating divinylbenzene (DVB), vinyltrimethoxysilane (VTMS), and 1-vinylimidazole (VIM). Characterization results indicate that this hydrogel shows good high-temperature and high-salinity stability, mechanical properties, and plugging ability in high-permeability layers. After aging in 20 × 104 ppm brine at 120 °C for 14 days, this gel still maintains good structural stability, with a swelling ratio of 706.98% and a relatively uniform particle size distribution. Thermal Gravimetric Analysis (TGA) shows that the onset decomposition temperature is 236.8 °C, higher than that of pure PAAm gel. Mechanical tests show that the fracture stress is 24 kPa with a maximum strain of 315%, enabling migration and plugging in porous media. Core flooding experiments demonstrate that the AD6S7I10 formulation (60 μL DVB, 70 μL VTMS, and 100 μL VIM) achieves a plugging efficiency of 92.41%. This hydrogel may serve as a candidate for profile control in complex reservoirs.

Gels doi: 10.3390/gels12110976

Authors: Razvan Gradinariu Dragos Ioan Virvescu Dana Gabriela Budala Monica Hancianu Monica Silvia Tatarciuc Teona Anamaria Tudorici Gabriel Rotundu Florinel Cosmin Bida Oana Maria Butnaru Ionut Luchian

Oral tissue regeneration is challenged by the diversity of dental tissues and by constant exposure to saliva, microbial biofilms, enzymatic activity, and mechanical loading. This review evaluated recent advances in regenerative and reparative hydrogels for periodontal and peri-implant tissues, the pulp–dentin complex, alveolar bone, extraction sockets, and oral mucosal wounds. PubMed/MEDLINE, Scopus, Web of Science, and ClinicalTrials.gov were searched for studies published between January 2000 and September 2026, with earlier landmark studies included when relevant. Eligible in vitro, animal, and clinical studies were synthesized narratively because of substantial methodological heterogeneity. Hydrogels provided adaptable carriers and matrices with injectable, adhesive, degradable, antimicrobial, immunomodulatory, angiogenic, and controlled-release functions. Advanced multifunctional systems produced promising regenerative effects, particularly in preclinical models. However, clinical evidence mainly concerned simpler topical or locally delivered gels and showed variable outcomes. Translation remains limited by inconsistent testing, insufficient simulation of oral conditions, sterilization-related changes, storage instability, manufacturing variability, and regulatory complexity. Future development should prioritize indication-specific design, standardized characterization, clinically relevant models, reproducible production, and long-term comparative trials. Hydrogels have considerable potential for oral tissue repair, but clinical value will depend on demonstrating safe, stable, practical, and reproducible benefits over existing treatments.

Gels doi: 10.3390/gels12110974

Authors: Petar Borisov Diana Cholakova Slavka Tcholakova

Commercial nonionic sucrose ester surfactants (SEs) contain varying ratios of monoesters and polyesters. In our previous study, we found that when the mono-to-polyester (MP) ratio is close to 1, SE dispersions can form hydrogels at very low surfactant and electrolyte concentrations. In the current study, we systematically investigate how the MP ratio and particle size affect the salt-induced gelation process. We reveal that SE dispersions form hydrogels only within a certain MP range. At low MP ratios (<0.4), micrometer-sized particles form and sediment, preventing gel formation, whereas at high MP ratios (≳3), particle concentration decreases, confining gelation to a very narrow electrolyte region. Sonication significantly reduces particle size across all dispersions, expanding the gelation domain down to MP ≈ 0.3. The critical salt concentration required for hydrogel formation exhibits a maximum as a function of MP ratio at MP ≈ 0.43, which is explained with the highest measured zeta potential for these particles. The obtained results support the hypothesis that increasing the monoester content enhances surface mobility, suppresses hydroxide ion adsorption, and reduces particle charge, thereby lowering the threshold electrolyte concentration. Finally, particle size reduction enhances overall gel strength and lowers the minimum surfactant concentration required for gelation. These findings enable the rational design of simple, biodegradable hydrogels with tunable properties for future applications in food, pharmaceutical, and cosmetic formulations.

Gels doi: 10.3390/gels12110973

Authors: Manuel Ros-Sirvent Pamela Chillagana María Isabel Lucío Ángel Maquieira Luis Antonio Tortajada-Genaro María-José Bañuls

Wearable sweat sensors are promising tools for non-invasive biomarker monitoring, but their development is hindered by the lack of standardized testing platforms and human sweat variability. Although hydrogels with high swelling capacity are attractive for sweat collection, poor post-swelling mechanical resistance often limits their application. To overcome this limitation, this study presents a mechanically robust, highly swellable hydrogel featuring surface microneedles (MN) that enhance sweat absorption kinetics through capillary fluid dispersion without microstructural collapse. The microneedle patch incorporates a PDMS-molded hydrophilic copolymer network with PEG-β-cyclodextrin-based pseudopolyrotaxanes as mobile crosslinking junctions to promote stress dissipation and structural integrity. Additionally, a benchtop sweat simulator was developed to deliver synthetic sweat with tunable, reproducible flow rates, compositions, and temporal profiles through a programmable interface. Using colorimetric pH monitoring as a proof-of-concept, the hydrogel demonstrated excellent performance across simulated biological variability, highlighting the vital role of material design in accelerating wearable biosensor translation.

Gels doi: 10.3390/gels12110972

Authors: Yuantao Xie Xiaoxin Feng Yuan Jia Xiufang Sun Chenguang Hu Gang Liu Ruiying Bai Yukun An

Ca leaching from steel-making slag (SS) has been widely used to obtain Ca-rich solutions for CO2 mineralization and calcium carbonate production, but the reutilization of the resulting solid residues remains insufficiently addressed. In this study, the effects of partially replacing cement with acetic acid-dissolved residue (HDR) or NH4Cl-dissolved residue (NDR) on mortar performance were evaluated. XRD analysis showed that Ca leaching altered the mineral assemblages of both residues, with the depletion of several Ca-bearing phases and the relative retention of Ca2(Al,Fe)2O5 and the RO phase. The mechanical performance of the residue-containing mortars depended on the residue source and replacement ratio. Low-to-moderate replacement levels retained useful compressive and flexural strengths, whereas excessive replacement reduced strength development. Appropriate incorporation of HDR or NDR maintained favorable sulfate-resistance coefficients, while 10–20% NDR improved freeze–thaw resistance. Calorimetry and microstructural observations showed that Ca-leached residues affected hydration heat evolution and the morphology of gel-like hydration products, while cement dilution and limited residue hydration contributed to the early-age strength loss at high replacement levels. These findings demonstrate the feasibility of reutilizing Ca-leached SS residues as partial cement replacements, provided that the replacement level is selected according to the required mechanical and durability performance of the mortar.

Gels doi: 10.3390/gels12110971

Authors: Salvatore Gallo Martina Lenzuni

Hydrogels are an important class of biomaterials due to their high water content, structural versatility, and ability to interact with biological environments [...]

Gels doi: 10.3390/gels12110970

Authors: Shi Duan Xia Zhong Bo Wei Yinfeng Xu Yilin Li Tao Wan Hua Dong

Conventional polyacrylamide-based plugging hydrogels suffer from severe performance deterioration caused by dehydration-induced shrinkage and subsequent gel migration under high-temperature reservoir conditions. Most existing modification strategies mainly improve the bulk mechanical properties of hydrogels, while few attempts focus on immobilizing hydrogels from the rock–hydrogel interface. Herein, we report a surface-anchored polyacrylamide hydrogel constructed via covalent grafting of polyacrylamide chains onto sandstone rock surfaces, aiming to suppress gel migration and sustain long-term plugging performance in heterogeneous reservoirs. Dual-parallel core-flooding, visual-model observation, and rock–hydrogel adhesion measurements were jointly performed to evaluate plugging durability and enhanced-oil-recovery potential. Immediately after gel formation, free hydrogels and anchored hydrogels exhibited comparable initial absolute plugging efficiency. Nevertheless, obvious performance gaps emerged during high-temperature aging. After aging for 10, 20, 30, and 40 days, the free hydrogel achieved plugging efficiencies of 91.5%, 68.4%, 28.7%, and 0.9%, while the anchored hydrogel yielded plugging efficiencies of 96.2%, 86.4%, 70.9%, and 35.5%, corresponding to relative improvements of 4.7%, 18.0%, 42.2%, and 34.6%, respectively. Such improvement originates from the largely enhanced rock–hydrogel interfacial adhesion (from 284 N/m2 for free hydrogel to 827 N/m2 for anchored hydrogel), which restricts gel detachment and migration upon dehydration and shrinkage. Correspondingly, in heterogeneous core-flooding tests, after aging for 10, 20, 30, and 40 days, the systems with free hydrogel obtained absolute total oil recoveries of 15.66%, 11.35%, 9.81%, and 9.21%, while the anchored-hydrogel systems reached 16.63%, 13.22%, 11.44%, and 9.98%, giving incremental oil recoveries of 0.97%, 1.87%, 1.63%, and 0.77%, respectively. This surface-grafting anchoring strategy shows promise for future field evaluation as a conformance-control agent for high-temperature heterogeneous reservoirs.

Gels doi: 10.3390/gels12110969

Authors: Mengmeng Liu Guoliang Zhao Suzhen Liu

The continuous monitoring of polymer gelation kinetics is important in engineering. As traditional characterization techniques inevitably disturb the fragile architectures of evolving matrices, high-frequency ultrasonic spectroscopy as a non-destructive alternative is increasing exploited to conduct perfect monitoring. This review establishes a comprehensive mathematical and physical framework that maps raw, experimental acoustic parameters directly onto dynamic macromolecular network topologies. (1) It evaluates the theoretical foundations bridging wave propagation mechanics and polymer rheology, analyzing how longitudinal moduli (M*) diverge from low-frequency shear parameters (G*) due to solvent compressibility and frequency-dependent observation windows. (2) It decodes how structural relaxation timescales and interfacial boundary dynamics dictate acoustic velocity curves and asymmetric attenuation anomalies by analyzing the acoustic signatures across covalent, physical and organic–inorganic hybrid networks. (3) It evaluates the state of multiscale computational modeling, from the principle of molecular dynamics theorems and finite volume element bonds to a method for extracting real-time mesh dimensions. (4) It discusses the technical barriers including the high-attenuation barrier as well as the emerging engineering breakthroughs like coded signal excitation. Finally, it outlines a predictive pipeline intended to change ultrasonic monitoring from a laboratory characterization method to an automated monitoring framework for gel manufacturing.

Gels doi: 10.3390/gels12110968

Authors: Jin Guo Xiaodong Dai Hu Meng

In unconventional reservoirs, the flowback efficiency of fracturing fluid is relatively low, resulting in the lower recovery rate of hydrocarbons. This work proposes a new method to improve the flowback of fracturing fluid by using cross-linked polymer nano-emulsion. Using the semi-continuous emulsion polymerization process, a core–shell polymer nano-emulsion was prepared with cross-linked core layer, namely FRACFLOW-WA. Through dynamic light scattering and transmission electron microscopy analysis, it was found that the average particle size of the nano-emulsion was 91.7 nanometers, with a narrow particle size distribution and excellent dispersion. The product can quickly adsorb on the pore surface and spontaneously form a uniform and stable hydrophobic film. The results showed that the contact angle of the core sample treated by the nano-emulsion at 1% concentration can increase to 108°. The hydrophobic film structure was confirmed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). The core gas flooding experiment showed that introducing 1% FRACFLOW-WA into the fracturing fluid increases the flowback efficiency to 72.3%, and the permeability recovery rate reaches 70.2%, which is better than the commonly used commercial surfactants. The Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) analysis results showed that the thickness of formed hydrophobic film is approximately only 2.34 nm, suggesting that this is a “lower damage” method to the pore structure. Based on the analysis of the mechanism, it is believed that the hydrophobic modification changes the surface of the pores from strong hydrophilicity to hydrophobicity, thereby converting the capillary pressure from resistance to a driving force that promotes fluid discharge.

Gels doi: 10.3390/gels12110967

Authors: Rita Fidalgo-Pereira Sara Lopes Orlanda Torres Nélio Veiga Pedro C. Lopes

White spot lesions (WSLs) are non-cavitated enamel lesions for which treatment success depends not only on initial lesion arrest or aesthetic improvement but also on long-term stability. This systematic review aimed to evaluate the long-term clinical, aesthetic, and remineralization outcomes of WSL treatments, with particular emphasis on treatment longevity and biomaterial-based approaches. A systematic search was conducted in PubMed, Scopus, and the Cochrane Library. Randomized controlled trials involving permanent teeth with ICDAS-assessed WSLs and a minimum follow-up of 12 months were eligible. Interventions included resin infiltration, fluoride-based therapies, remineralizing gels, casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) formulations, hydroxyapatite, self-assembling peptides, microabrasion, bleaching, and combined approaches. Risk of bias was assessed using the Cochrane Risk-of-Bias 2 tool. Due to substantial clinical and methodological heterogeneity, a conventional pooled meta-analysis was not considered appropriate. Nine publications representing eight independent randomized controlled trials, with follow-up periods of 12–36 months, were included. Resin infiltration demonstrated the most consistent long-term aesthetic benefits and sustained reductions in visible WSL area. Non-invasive approaches, including fluoride-based therapies and remineralizing gels, generally improved outcomes from baseline; however, the additional benefits of specific formulations, including CPP-ACP/CPP-ACPF and fluoride-containing gels or varnishes, were inconsistent compared with conventional fluoride toothpaste. Limited quantitative comparisons favored resin infiltration over fluoride varnish, CPP-ACP, and fluoride toothpaste for lesion-area reduction. The certainty of evidence was low for aesthetic outcomes and very low to low for remineralization and lesion progression outcomes. Resin infiltration showed the most consistent long-term clinical and aesthetic benefits, maintained for up to 24 months. Non-invasive strategies may support lesion regression and remineralization, but their additional long-term benefits remain uncertain and appear dependent on formulation and treatment protocol. However, direct evidence of treatment durability was limited, as several trials assessed long-term effectiveness during continuous or repeated treatment rather than the maintenance of an initially achieved response. Recurrence and retreatment were inconsistently reported, and prevention of new WSLs represented a distinct clinical outcome. Further well-designed trials with standardized outcomes and longer follow-up are needed to establish the comparative effectiveness and longevity of biomaterial-based treatments for WSLs.

Gels doi: 10.3390/gels12110966

Authors: Lala Li Jiawei Xue Suaiying Shang Yongpeng Yin Hongju Zhang Denglin Luo Lihua Zhang Bakht Ramin Shah Wei Xu

To develop palm oil-reduced functional ice cream, this study investigated the effects of replacing palm oil with konjac glucomannan (KGM)-based double emulsions (PDEs) at varying substitution rates (0–100%) on the physicochemical properties, structural performance, and sensory quality of ice cream. A conventional full-fat formulation containing the original palm oil level was used as the control. The results showed that, compared with the full-fat control, increasing the palm oil replacement ratio increased the viscosity and shear-thinning behavior of the aged ice cream mix. Microstructural analysis revealed reduced fat globule size and an altered bubble structure. Overrun and gas-hold-up decreased, whereas melt resistance and hardness increased. The apparent DPPH radical scavenging activity increased with the replacement ratio and reached 94.16% at a 100% replacement ratio, which was mainly attributed to the encapsulated epigallocatechin gallate (EGCG) and β-carotene. Sensory evaluation indicated that 50% replacement formulation had the closest overall acceptability to the full-fat control, whereas higher replacement ratios reduced acceptability, likely because of the bitter taste of EGCG. Correlation analysis confirmed significant relationships between overrun and melting rate and between hardness and sensory acceptability. In summary, KGM-based PDEs can be used to replace palm oil in functional ice cream, and a 50%replacement ratio maintained sensory acceptability while enhancing antioxidant activity.

Gels doi: 10.3390/gels12110965

Authors: Faouzia Tayari Kais Iben Nassar João Pedro Carvalho Sílvia Soreto Teixeira Imen Hammami Sílvia Rodrigues Gavinho Manuel P. F. Graça Manuel Almeida Valente

In the original publication [...]

Gels doi: 10.3390/gels12110964

Authors: Vlad Mihai Chiriac Andrei-Alexandru Ivu Alina Gabriela Rusu Alina Ghilan Alexandru Mihail Serban Alexandra Vieru Loredana Elena Nita Aurica P. Chiriac

The escalating global threat of antimicrobial resistance (AMR) necessitates innovative therapeutic platforms beyond conventional antibiotics. Antimicrobial peptides (AMPs) coordinated with rhenium(I) tricarbonyl complexes ([fac-Re(CO)3]+) represent a promising class of metallodrugs, merging the rapid membrane-disrupting action of AMPs with the oxidative stress, intracellular targeting, or theranostic potential of Re(I) centers. Encapsulation of these conjugates into (nano)microgel matrices further improves proteolytic stability, enables controlled or stimuli-responsive release, and supports localized delivery while minimizing systemic toxicity. Artificial intelligence (AI), including deep learning, generative models, and multi-objective optimization, dramatically accelerates every stage—from de novo AMP sequence design and metal-binding motif engineering to Re coordination prediction and rational nanogel formulation. This review outlines a proposed framework in AI-driven AMP discovery, Re-metallopeptide synthesis, nanogel/microgel delivery systems, and their integrated application. It highlights machine-learning (ML) and generative approaches for rapid optimization while addressing key challenges such as data scarcity, scalability, biocompatibility, and in vivo validation. Future directions emphasize closed-loop, multi-objective AI frameworks for personalized, smart antimicrobial platforms.

Gels doi: 10.3390/gels12110963

Authors: Yuchen Wen Jincai Wang Yinuo Pan Yincheng Liu Nu Lu Ruicheng Ma Jirui Hou

Gel plugging in wellbores and near-wellbore regions caused by polymer adsorption and retention severely hinders fluid injection and production efficiency in post-polymer flooding reservoirs. To address this issue, a highly efficient chemical plug removal agent was formulated and selected. Under reservoir conditions of 65 °C and a salinity of 6864 mg/L, the system exhibited excellent dispersion stability, with a Zeta potential of −36.7 mV. It achieved a viscosity-reduction rate exceeding 95% for polymers across various molecular weights. The microscopic degradation mechanism was elucidated based on the published literature and experimental results. Fe2+ activation triggered the generation of highly reactive SO4•− and HO• radicals. Under acidic conditions (pH ≤ 6), the reaction was dominated by controlled SO4•− radicals, breaking down dense three-dimensional gel networks, which dramatically reduced the aggregate size from 500~2000 nm to 10~30 nm. Dynamic coreflooding tests demonstrated that injecting the system lowered the residual resistance factor from 6.5 to 1.0~1.5, achieving a permeability recovery rate exceeding 80%. Field trial results further verified that application of the composite plug removal agent and subsequent acid stimulation decreased injection pressure from 12.5 MPa to 5.5 MPa, increasing the apparent water-injectivity index to 2.4 times its initial value. This study provides crucial theoretical insights and technical support for efficient near-wellbore unplugging and residual oil mobilization in post-polymer flooding reservoirs.

Gels doi: 10.3390/gels12110962

Authors: Huixia Wu Zhiming Ma Chaofeng Liang

Partial replacement of cement by concrete waste micropowder in ultra-low-w/b cementitious composites is an effective strategy to reduce carbon emissions and promote the high-value utilization of concrete waste. While existing studies have predominantly focused on the effect of concrete waste micropowder on high-w/b cementitious composites systems, investigations on ultra-low-w/b cementitious composites remained limited. Therefore, this study examined the influence of concrete waste micropowder type and replacement ratio on the performance of ultra-low-w/b cementitious composites. The results indicated that moderate cement substitution by concrete waste exerted a minor impact on hydration and hydration products and enhanced multi-scale mechanical properties. In contrast, high-volume replacement (above 30%) weakened the hydration process, reduced both the quantity and quality of hydration products, and degraded the micro-to-macro performance. Nevertheless, even at 70% replacement, the ultra-low-w/b cementitious composites retained exceptional mechanical performance and a high strength retention rate, with a 28-day compressive strength still exceeding 120 MPa. Based on the hydration data of ultra-low-w/b cementitious composites incorporating concrete waste micropowder, a kinetic model was established and the corresponding kinetic parameters were determined. In addition, the ultra-low-w/b cementitious composites with ground concrete micropowders and those with ground mortar micropowders exhibited comparable microstructure and mechanical performance, both of which were superior to those with ground paste micropowder. Co-incorporation of granulated blast furnace slag or fly ash with concrete waste micropowder further improved the microstructure and multi-scale mechanical performance.

Gels doi: 10.3390/gels12110961

Authors: Domnica-Elena Bîrgăuan Liliana Anchidin-Norocel Oana C. Iatcu Sergiu Pădureţ Mihai Covasa

Functional jellies represent attractive matrices for delivering bioactive compounds. This preliminary pilot study aimed to develop and characterize an agar-based jelly formulated with trans-resveratrol (RSV) and explore cognitive outcomes following its consumption in healthy adults. An agar-based jelly was formulated with a nominal amount of 200 mg of trans-resveratrol incorporated per approximately 5 g serving. RSV-containing and placebo formulations were evaluated for color, water activity, textural and viscoelastic properties, and sensory acceptance. Compared with the milk powder-containing placebo formulation, the RSV-containing jelly exhibited significantly lower firmness, hardness, springiness, gumminess, and chewiness than the placebo (p < 0.05), while adhesiveness, cohesiveness, and resilience did not differ significantly. Stress relaxation analysis revealed viscoelastic behavior in both formulations, with significantly higher equilibrium stress, relaxation time, equilibrium modulus, and viscosity in the placebo formulation (p < 0.05). In a randomized, placebo-controlled, single-blind pilot study, 20 healthy adults consumed one jelly daily for 21 days. There were no significant differences in working-memory performance over the intervention period and shorter TMT completion time in the RSV group at day 21 compared with placebo. No between-group differences were observed in Stroop interference. Given the study limitations including small sample size, potential practice effects, single-blind design, and compositional differences between formulations, the cognitive findings should be regarded as preliminary and hypothesis-generating.

Gels doi: 10.3390/gels12110960

Authors: Yongshun Feng Zhuan Chen Shuqi Guo Xin Pan Hui Qiao Guoqiang Zhu Xiaowei Zhuang

Ion-conductive polyacrylamide (PAM) hydrogels hold great potential in flexible sensing applications. The pure PAM hydrogels exhibit low mechanical strength and cyclic performance. Hierarchical multi-scale bamboo macro-cellulose fiber and nano-cellulose fiber are developed to modify PAM ion-conductive hydrogels, using a ZnCl2/AlCl3 binary solvent. SEM results show that the addition of bamboo cellulose to the PAM hydrogel reduces the pore structure, but no agglomeration is observed. FTIR results show that hydrogen bonding interactions occur among bamboo fibers, water, and the PAM matrix. The hydrogels modified by bamboo fibers retain flexibility, transparency, and adhesivity. The ionic conductivity of modified hydrogels is in the range of 32–46 mS/cm. The tensile strength of hydrogels improves moderately from 0.1 MPa to 0.15 MPa with elongation over 1600%. The bamboo nano-cellulose fiber shows a higher enhancement effect on mechanical strength. The hydrogels possess good cyclic tensile and compressive performance in 20 consecutive cyclic tests. This bamboo multi-scale fiber modification strategy provides a simple and sustainable method for property improvement of flexible conductive hydrogels.

Gels doi: 10.3390/gels12110959

Authors: Seyed Mohammad Taghi Gharibzahedi David Julian McClements

Bigels are biphasic gel systems formed by combining oleogels and hydrogels. Bigels can encapsulate both hydrophilic and hydrophobic substances and have attracted interest as edible inks in the 3D printing of functional foods and sensors. This review evaluates bigel-based food systems, with emphasis on their applications as edible inks for 3D food printing, from a formulation–process–product perspective. The potential applications of bigel-based systems for bioactive delivery, fat substitution, lipid structuring, and color-responsive freshness indicators are reviewed. Bigels are being used as edible inks in 3D food printing applications, including single-nozzle, multi-material, and coaxial extrusion techniques. The types and ratios of hydrogels and oleogels influence printability by modifying phase organization, interfacial interactions, shear-thinning behavior, and structural recovery. The polysaccharide and/or protein networks in the hydrogel phase can be designed to provide shear-thinning and structural recovery properties, while the wax-, ethylcellulose-, and/or monoglyceride networks in the oleogel phases can be designed to provide mechanical strength. Conventional bigel systems have been investigated for the encapsulation and release of hydrophilic and lipophilic bioactive compounds under simulated gastrointestinal conditions, providing relevant information for the development of 3D-printable delivery systems. Bigel-based formulations have also been investigated for texture-modified foods, personalized nutrition, and plant-based products, with varying levels of evidence for their application in 3D-printed foods. Bigel-based fat replacers can offer improved nutritional profiles while still providing desirable textural and functional attributes of traditional fats. Color-responsive bigels have been investigated as freshness indicators for food quality monitoring, with potential applications in 3D-printed food systems and packaging materials. The limitations of 3D-printed bigels, including scale-up, cost, time, and print performance, are finally reviewed. By distinguishing well-documented applications of conventional bigels from emerging uses in 3D food printing, this review identifies critical research gaps that must be addressed to advance their practical use.

Gels doi: 10.3390/gels12110958

Authors: Husam Qanash Naif K. Binsaleh Abdulrahman S. Bazaid Hour A. Altamimi Ghaida Alsaif Talal Alharazi Bandar Alharbi

Laurus nobilis L. essential oil displays a broad range of biological activities, yet its poor aqueous dispersibility, high volatility and susceptibility to oxidative degradation restrict its use in aqueous biological systems. In this study, an ultrasound-assisted L. nobilis oil nanoemulsion (LNNO) was formulated, characterized and, within a single experimental framework, compared directly with the unformulated oil for its antimicrobial, antibiofilm, cytotoxic and wound-closure responses. GC-MS profiling identified eucalyptol (1,8-cineole; 35.12%) as the predominant constituent. LNNO showed an intensity-weighted Z-average hydrodynamic diameter of 77.10 nm (number-weighted mean 72.30 ± 0.5 nm; TEM 65.4 nm), a PDI of 0.231, and an apparent zeta potential of −31.10 mV, and it remained nanoscale without visible phase separation over 60 days of storage. LNNO inhibited all six tested microorganisms (MIC 7.8–31.25 µg/mL), with MIC values four- to eightfold lower than those of pure oil, and reduced biofilm biomass by up to 96.80% (Bacillus subtilis) and 96.63% (Candida albicans) at 75% of the MBC/MFC; at this level concentrations equal or exceed the MIC, and the least confounded antibiofilm comparison (25% MBC/MFC, below MIC) still showed 45.28–72.45% inhibition versus 18.45–32.61% for pure oil. In Caco-2 colorectal adenocarcinoma cells, the MTT IC50 of LNNO was approximately half that of pure oil (107.4 versus 215 µg/mL), whereas the IC50 in normal HFB4 fibroblasts was 368.81 µg/mL (selectivity index 3.43). At a non-cytotoxic concentration, LNNO increased scratch closure in HFB4 monolayers from 28.4 ± 2.1% (untreated) and 30.1 ± 2.4% (oil-free vehicle) to 58.7 ± 3.2% at 48 h (p < 0.001; n = 3 independent experiments). The oil-free vehicle was inactive in all assays. In a single preliminary compatibility experiment, LNNO retained nanoscale dispersion and antimicrobial activity after incorporation into a carbomer gel, while the blank gel was inactive. Together, these data show that nanoemulsification improves the measured in vitro responses to L. nobilis oil and provides a characterized platform for mechanistic studies and subsequent in vivo evaluation.

Gels doi: 10.3390/gels12110957

Authors: Lixin Ma Zhou Qin Wenya Zhang Pengpeng Yu

Food gels are soft materials in which three-dimensional (3D) networks of proteins, polysaccharides, lipids, or their composites immobilize water, oil, or gas and provide tunable rheological, mechanical, and functional properties. Performance assessment remains inconsistent across studies, as researchers often report gel strength or water-holding capacity alone and rarely compare different gel systems using common criteria. The assumption that denser networks perform better also remains largely untested. This review organizes the field around a cross-scale pathway from external triggers and intermolecular interactions to mesoscale networks and macroscopic functions. It applies this framework to hydrogels, oleogels, and bigels and links their preparation methods to multiscale characterization. Network densification does not necessarily improve performance: it may enhance water-holding capacity and barrier properties but also restrict flavor release, reduce enzyme accessibility, and compromise swallowing safety. Therefore, the optimal network structure should be defined for each application rather than maximized. These trade-offs are relevant to delivery systems, fat replacement, 3D printing, edible coatings, and intelligent indicators. Future research should establish unified structure–digestion–sensory metrics, validate data-driven models externally, and test gel performance under realistic storage and use conditions.

Gels doi: 10.3390/gels12110956

Authors: Juan D. Rivera-Giraldo Yaned M. Correa-Navarro Nancy R. Sanabria-González

Diclofenac (DCF) is a widespread pharmaceutical pollutant in aquatic environments requiring efficient treatment strategies. This study evaluated alginate/graphite oxide (Alg/GrO) hydrogel beads as a sustainable solution for removing DCF from aqueous systems. Graphite oxide, synthesized via a modified Hummers method, was incorporated into an alginate matrix. One-Factor-at-a-Time (OFAT) experiments were conducted to screen operational parameters, establishing that DCF adsorption was favored at pH 6.0, 200 rpm stirring speed, and 180 min contact time. Holding these parameters constant, the effects of the initial DCF concentration and Alg/GrO dosage were modeled and optimized using a Central Composite Design (CCD) combined with Response Surface Methodology (RSM). Under optimal conditions (34.2 mg L−1 DCF and 2.55 g L−1 Alg/GrO containing 2 wt.% GrO), removal efficiencies exceeded 90%. Adsorption kinetics followed a pseudo-first-order model (R2 = 0.973), typical of physical adsorption, indicating that the adsorption rate depends on the number of available adsorption sites on the material surface. Equilibrium data best fit the Sips isotherm (R2 = 0.999), yielding a maximum capacity of 91.50 mg g−1 at 20 °C. Thermodynamic parameters confirmed a spontaneous (ΔG0 < 0) and exothermic adsorption process (ΔH0 = −17.05 kJ mol−1). Reusability tests demonstrated consistent performance across consecutive cycles. Overall, Alg/GrO hydrogel beads constitute an effective, sustainable, and reusable alternative for DCF removal.

Gels doi: 10.3390/gels12110955

Authors: Hailong Zhang Yangdong He Jun Liao Shanhong Guo Weicai Wan Bing Lin Shiyu Li Junlei Tang

Ethyl cellulose (EC)-based supramolecular gel coatings are melt-coated and conformable to complex geometries, but their durability under coupled environmental exposures remains unclear. Here, C-EC, C-EC/TPU, and C-EC/Fe3O4 coatings were subjected to 600 h UV aging, 150 days of immersion in 3.5 wt.% NaCl, 150 days neutral salt spray, and ten exposure–remelting–reapplication cycles. Natural exposure was conducted for up to 360 days in Wanning and Qingdao, whereas only C-EC was applied to pipes, angle sections, bolts, and flanges. Single-factor tests revealed exposure-dependent changes in surface morphology, optical properties, tensile strength, and ester-related FTIR features. Natural exposure additionally involved atmospheric deposition, localized fouling, seasonal variation, and fungal presence. After 360 days in Qingdao, all three coatings exhibited gloss values below 1 GU. In Wanning, an Aureobasidium-dominated fungal community was detected in material from discolored areas of a C-EC-coated flange and pipe. After C-EC coating removal from structural components, no obvious macroscopic rust was observed in the examined covered regions. SEM showed increased surface heterogeneity, while FTIR revealed changes in ester-related absorption features. Oil redistribution or loss, hydrolysis, and oxidation were not directly measured and remain possible degradation processes. Laboratory and natural exposure should therefore be correlated through shared observable aging features rather than direct time equivalence.

Gels doi: 10.3390/gels12110954

Authors: Ákos Tamás Nagy Sándor Bogdán Árpád Joób-Fancsaly György Szabó Dániel Végh Zsolt Németh Gábor Kammerhofer

Blue®M is an oral biomaterial product line based on active oxygen-generating formulations containing sodium perborate, honey-derived glucose oxidase, and lactoferrin, available as an oral gel, mouthwash, and toothpaste. This narrative review summarizes the human clinical evidence by product type and clinical indication, with a study-level risk of bias assessment. A structured search of PubMed/MEDLINE, Embase, CENTRAL, and Google Scholar, completed on 27 September 2026, identified 35 eligible human clinical studies. Risk of bias was formally assessed with the revised Cochrane risk of bias tool for 32 randomized trials, including split-mouth designs, and with ROBINS-I for three non-randomized comparative studies. The oral gel was mainly investigated as an adjunct to scaling and root planing and as a topical treatment for postoperative wounds. Periodontal findings were heterogeneous: probing pocket depth and attachment-level gains were reported in several small split-mouth trials with some concerns or serious risk, whereas no statistically significant between-group benefit was detected in the only trial that was at low risk of bias. Several small studies reported more favorable short-term pain and re-epithelialization outcomes than a conventional periodontal dressing, predominantly at high risk of bias. Mouthwash studies showed no statistically significant between-group differences compared with chlorhexidine, while toothpaste studies showed no consistent superiority over reference products. Overall, the available evidence, weighted by risk of bias, does not demonstrate superiority of Blue®M over established treatments; it may be regarded as a potentially useful adjunct whose comparative clinical value remains uncertain. Adequately powered randomized trials with a blinded outcome assessment, registered protocols, and active comparators are needed.

Gels doi: 10.3390/gels12110953

Authors: Yutong Mei Yuhan Fu Sisi Yan Weinan Li Yanhong Wang

Diabetic wounds are sustained by a complex and dynamic pathological network involving hyperglycemia, persistent inflammation, oxidative stress, impaired angiogenesis, extracellular matrix degradation, and microbial biofilms, which collectively limit the effectiveness of conventional passive dressings. This review summarizes recent advances in hydrogel delivery systems for diabetic wound healing and classifies them according to the principal strategy by which therapeutic performance is integrated into the hydrogel platform, focusing on stimuli-responsive hydrogels, nanocomposite hydrogels, and natural bioactive self-assembled hydrogels. Stimuli-responsive hydrogels exploit wound-associated cues, including reactive oxygen species, pH, glucose, matrix metalloproteinases (MMPs), and temperature, to enable on-demand and spatiotemporally controlled therapeutic delivery. Building on this precise release control, nanocomposite hydrogels integrate lipid-based nanocarriers, bio-derived vesicles, or inorganic nanomaterials into macroscopic hydrogel networks to improve cargo stability, local retention, and sustained delivery. Natural bioactive self-assembled hydrogels further broaden hydrogel design by extending it from therapeutic cargo regulation and delivery to the direct participation of bioactive molecules in material construction. Through non-covalent interactions, these molecules function as both therapeutic agents and structural units, integrating bioactivity with hydrogel formation. Collectively, these strategies progressively integrate controlled release, enhanced therapeutic delivery, and bioactive material construction to address the multifaceted pathological barriers of diabetic wounds, including inflammation, oxidative stress, infection, impaired angiogenesis, and defective tissue regeneration. This review also discusses the current challenges and future perspectives of these hydrogel delivery systems and aims to provide valuable reference for the rational design and clinical translation of advanced hydrogel delivery systems for diabetic wound healing.

Gels doi: 10.3390/gels12110951

Authors: Nina Danchova Dimitar Shandurkov Tony Spassov Stoyan Gutzov

Silica–chitosan hybrid gel composites containing up to 3.3 wt% chitosan are prepared by a simple and reproducible sol–gel route based on the acid-catalyzed hydrolysis and condensation of tetraethoxysilane. The resulting materials are characterized by UV–Vis and FTIR spectroscopy, thermogravimetric and differential thermal analysis, scanning electron microscopy, X-ray diffraction, and thermal conductivity measurements. Increasing the chitosan content resulted in densification of the silica network from 1.56 to 1.70 g·cm−3. Even at low chitosan concentrations, its incorporation produces measurable changes in the structural, optical, and thermal properties of the sol–gel-derived silica, thus preserving its amorphous nature. The thermal conductivity of the gels decreases from 0.1 W/m·KW/m·K to 0.09 W/m·K with chitosan doping, combined with an increase in optical absorption at 300 nm. A simple empirical method based on UV–Vis reflectance spectroscopy is proposed for determining the chitosan content in silica powders. Optical properties of low-doped silica gels and chitosan solutions are described. Hydrothermal treatment of the chitosan solution improves optical absorption at 285 nm. Overall, the preparation–structure–property relationships of the hybrid gels demonstrate their potential as optical matrices with tunable properties.

Gels doi: 10.3390/gels12110952

Authors: Changming Li Hekai Zhang Yaozhong Wang Dongyang Jia Mingyan Lv Yun Chai Shuxian Lu Jingyuan Zhao

The water-induced swelling and disintegration of pisha sandstone (PS) are modified through gel-mediated cementation, thereby providing a technical pathway for the resource utilization of PS. This study investigated the durability of PS geopolymer cementitious materials (PSCM) incorporating four industrial solid wastes, including blast furnace slag (BFS), fly ash (FA), silica fume (SF), and steel slag (SS), under dry–wet cycles, freeze–thaw cycles, and water immersion. X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy were employed to characterize the evolution of the mineral phase composition and gel structure of PSCM. The results show that BFS can effectively improve the durability of PSCM. With 40% BFS, the strength of PSCM reaches 25.82 MPa after 10 dry–wet cycles; the strength loss rate drops to 27% after 10 freeze–thaw cycles; and the softening coefficient reaches 0.89 after 28 d immersion. With 20% BFS, the strength loss of PSCM specimens is only 10.3% and 9.3% after 10 dry–wet and freeze–thaw cycles followed by 7 d immersion. BFS promotes the formation of calcium-rich C-A-S-H gels, enhancing interparticle bonding and matrix integrity, thus enhancing the durability of PSCM. This study provides a theoretical basis for understanding the microstructure evolution and durability differences in PSCM modified by different solid wastes.

Gels doi: 10.3390/gels12110950

Authors: Shu Li Jia Li Wenyu Meng Cai Wang

Traumatic hemorrhage is a leading cause of death worldwide, especially in pre-hospital emergency care, battlefield scenarios, and complex surgeries. Irregular wounds (lacerations, blast injuries, penetrating wounds, visceral incisions) with uneven depth and jagged edges pose challenges to hemostasis. Traditional methods such as mechanical compression, surgical suturing, gelatin sponges, and gauze show low efficiency, single functionality, and lack antibacterial activity for deep or irregular wounds. Therefore, developing a material combining rapid hemostasis, antibacterial efficiency, and antioxidant capacity is urgently needed. Phenylboronic acid was grafted onto sodium hyaluronate (HA) to form a boronate ester network (HA-PBA). The HA-PBA solution was combined with polydopamine-grafted hyaluronic acid nanoparticles (PDA-HA) and quercetin (Que) to prepare a photothermal-responsive HP@PDA/Que3 hydrogel dressing. The hydrogel was evaluated for photothermal performance, antioxidant capacity, biocompatibility, hemostasis, and antibacterial activity. The HP@PDA/Que3 hydrogel possessed a porous network. Optimal concentrations were 0.8 mg/mL PDA-HA and 0.3 mg/mL Que. The hydrogel exhibited > 65% DPPH/ABTS radical scavenging and cleared intracellular ROS. It showed injectability, tissue adhesion, swelling, and controllable degradation. Under NIR irradiation, the antibacterial rates against S. aureus and E. coli exceeded 99%. Biocompatibility tests showed favorable in vitro biocompatibility, with no obvious cytotoxicity (cell viability > 85%) and a hemolysis rate < 5%. These in vitro results cannot fully guarantee in vivo biosafety, and further histological evaluation of local inflammatory responses is required prior to clinical translation. In vitro coagulation tests confirmed procoagulant properties. In a rat liver incision model, hemostatic time and blood loss were better than those of chitosan and blank control groups. The HP@PDA/Que3 hydrogel integrates rapid hemostasis, photothermal antibacterial activity, antioxidant function, and biocompatibility, providing a multifunctional dressing with clinical potential for trauma emergency treatment.

Gels doi: 10.3390/gels12110949

Authors: Halil İbrahim Yavuz Umut Kaan Özbaş

Two hydrogels made to the same recipe in two laboratories need not be the same material, and the descriptor sets in routine use do not explain why. We argue that machine learning for hydrogels is limited by representation, not architecture. Of the thirteen variables that set a gel’s stiffness, four reach the data table; and with composition fixed completely, 1728 measurement protocols remain, each returning a number published under one heading. Neither the inputs nor the targets are what their names suggest. We diagnose four compounding failure modes and propose a minimum reporting set and benchmark tasks defined by their splits.

Gels doi: 10.3390/gels12110948

Authors: Dongyang Zhu Kexin Zheng Yimeng Ren Haoyue Chang Zhe Xu Zhuangli Kang

This study evaluated the efficacy of yeast protein (YP) supplementation at 0%, 2%, 4%, and 6% (w/w, relative to meat weight) in mitigating quality defects commonly observed in low-salt (1% NaCl) chicken meat batters, including reduced water-holding capacity, textural deterioration, and insufficient gel strength. The results demonstrated that YP incorporation substantially alleviated these defects. Notably, compared with the conventional 2% NaCl control (T1), the 4% YP formulation (T4) exhibited significantly higher cooking yield, hardness, and gel strength (p < 0.05), whereas water-holding capacity, L* value, and springiness were not significantly different (p > 0.05). Rheological analysis showed that the storage modulus (G′) at 80 °C increased with increasing YP content. Fourier transform infrared spectroscopy indicated that YP promoted a secondary structural transition from α-helices to β-sheets. Cryo-SEM revealed that YP addition resulted in a denser and more ordered gel network. However, increasing YP to 6% caused undesirable gel darkening and a significant decrease in appearance score, although overall acceptability did not differ significantly from T1, T3, or T4. Among the tested concentrations, 4% YP was identified as the optimal supplementation level, significantly enhancing the gel quality of low-salt chicken meat batters while maintaining desirable product characteristics. These findings highlight the promising potential of YP in the development of low-salt meat batter products.

Gels doi: 10.3390/gels12110947

Authors: Zhongyi Qiu Wenbo Xu Ruiqian Wang Wenguang Yang Long Zhang

Soft crawling robots offer high compliance, large deformation, and adaptability to complex, unstructured environments. These properties make them promising for miniature inspection systems, biomedical applications, intelligent manufacturing, and operation in extreme environments. Conventional rigid robots rely on complex mechanical structures and articulated joints with multiple degrees of freedom, whereas soft robots achieve actuation and locomotion primarily through the controlled deformation of smart materials. Thin films and gel-based materials (such as hydrogels and ionic gels) are particularly attractive because of their low mass, high flexibility, large strain capacity, and ease of integration. Functionalization, including the incorporation of specific functional groups, enables responses to electrical, thermal, optical, magnetic, and humidity stimuli. These materials are therefore becoming key functional components of next-generation soft crawling robots. This review examines recent advances in soft crawling robots actuated by thin-film and gel materials. The principal smart materials are classified by actuation mechanism into dielectric elastomer actuators (DEAs), liquid crystal elastomers (LCEs), magnetoactive elastomers (MAEs), ionic polymer–metal composites (IPMCs), hydrogels, and shape-memory polymers (SMPs). Their actuation mechanisms, mechanical properties, and application scenarios are analyzed. The material systems are compared in terms of deformation capability, force output, response time, energy requirements, durability, fabrication complexity, robot integration and miniaturization, motion control, environmental adaptability, and functional versatility. The review also identifies major challenges related to material stability, cyclic durability, electrical and thermal requirements, dehydration, external-field dependence, interfacial reliability, fabrication reproducibility, and scalable manufacturing. Advances in multimaterial integration, hybrid actuation, intelligent manufacturing, self-sensing, and closed-loop control are expected to improve system integration, adaptability, autonomy, and multifunctionality.

Gels doi: 10.3390/gels12110946

Authors: Yingan Li Zimiao Zang Zhiyang Zhao Gaofeng Shao

The inherent brittleness of conventional nanoparticle-based silicon carbide (SiC) aerogels severely limits their practical application in extreme environments requiring thermal insulation. Herein, we report a hierarchically configured zero- and one-dimensional (0D-1D) SiC nanowire–granule (SiC-NG) aerogel synthesized via a precursor infiltration–gelation and pyrolysis strategy. By infiltrating bridged polysilsesquioxane (BPSi) precursor solutions into pre-synthesized BPSi aerogel scaffolds, in situ growth of 1D SiC nanowires is achieved within the 0D granular skeleton, constructing an interpenetrating “point–line” network architecture. The resulting SiC-NG aerogel exhibits a low density of 0.121 g cm−3 and a high porosity of 87.02%. This hierarchical configuration substantially enhances mechanical robustness, delivering a compressive strength of 0.251 MPa and elastic modulus of 1.619 MPa, outperforming conventional granular SiC aerogels. Moreover, the aerogel demonstrates good thermal insulation performance, maintaining a cold-side temperature of only 300 °C after 5 min of direct exposure to a 1300 °C butane flame. This work establishes a versatile strategy for designing mechanically reinforced, hierarchically structured ceramic aerogels for advanced thermal protection under extreme environments.