Gels | November 2025 - Browse Articles

16 pages, 3789 KB

Open AccessArticle

Antibacterial and Biocompatible Penicillin–Streptomycin Loaded Bacterial Cellulose (BC) Hydrogels for Wound Healing

by Sanosh Kunjalukkal Padmanabhan, Maria Elena Giordano, Stefania Villani, Gayatri Udayan, Mariangela Stoppa, Pietro Alifano, Christian Demitri, Maria Giulia Lionetto and Antonio Licciulli

Gels 2025, 11(11), 851; https://doi.org/10.3390/gels11110851 (registering DOI) - 24 Oct 2025

Abstract

Bacterial cellulose (BC) hydrogel is a promising skin wound healing biomaterial due to its unique properties, including a moist environment that facilitates tissue healing. To enhance its antimicrobial efficacy, BC dressings were loaded with penicillin and streptomycin. FT-IR analysis confirmed successful drug binding, [...] Read more.

Bacterial cellulose (BC) hydrogel is a promising skin wound healing biomaterial due to its unique properties, including a moist environment that facilitates tissue healing. To enhance its antimicrobial efficacy, BC dressings were loaded with penicillin and streptomycin. FT-IR analysis confirmed successful drug binding, while SEM revealed a nanofibrous and porous hydrogel structure. In vitro studies using 3T3 mouse fibroblasts demonstrated biocompatibility, and scratch wound assays achieved complete closure across all tested concentrations. Antibacterial activity, assessed via agar diffusion against Pseudomonas aeruginosa and Staphylococcus aureus, showed a concentration-dependent increase in inhibition zones, highlighting the potential of BC-Pen/Strep hydrogels as effective antimicrobial wound dressings. Full article

(This article belongs to the Special Issue Cellulose-Based Hydrogels for Advanced Applications)

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18 pages, 3809 KB

Open AccessArticle

Dialdehyde Starch Cross-Linked Collagen with Heparin Conjugation: Characterization and Feasibility Study for Osteochondral Tissue Repair

by Jason K. Lee, Jihye Baek, Shawn P. Grogan, Tae-Hoon Koo and Darryl D. D’Lima

Gels 2025, 11(11), 850; https://doi.org/10.3390/gels11110850 (registering DOI) - 24 Oct 2025

Abstract

Collagen is widely used in tissue engineering due to its excellent biocompatibility; however, its limited intrinsic mechanical strength restricts its application in load-bearing environments. This study introduces dialdehyde starch (DAS) as a biocompatible macromolecular cross-linker to enhance the mechanical integrity of collagen hydrogels. [...] Read more.

Collagen is widely used in tissue engineering due to its excellent biocompatibility; however, its limited intrinsic mechanical strength restricts its application in load-bearing environments. This study introduces dialdehyde starch (DAS) as a biocompatible macromolecular cross-linker to enhance the mechanical integrity of collagen hydrogels. Collagen gels were cross-linked with DAS during neutralization under optimized conditions, resulting in a significant increase in compressive stiffness (up to ~125 kPa), thereby improving their suitability for mechanically demanding applications. Degradation studies of DAS-crosslinked collagen confirmed the long-term stability of the gel, while post-neutralization heparin incorporation improved bifunctionality, as evidenced by increased surface retention. FT-IR analysis confirmed the successful DAS cross-linking and heparin conjugation while preserving the native collagen structure. Bioactivity assays of DAS-crosslinked and heparin-conjugated collagen gel demonstrated enhanced chondrocyte migration in PDGF-BB-functionalized gels and improved cell viability, proliferation, and matrix deposition in TGF-β3-treated constructs. Preliminary ex vivo culture using a rabbit osteochondral defect model showed promising tissue integration and glycosaminoglycan accumulation. These results highlight the potential of DAS-crosslinked and heparin-conjugated collagen hydrogels as mechanically robust and biologically supportive scaffolds for osteochondral tissue engineering and regenerative medicine applications. Full article

(This article belongs to the Special Issue Hydrogels for Cartilage Tissue Engineering and Mechanobiology)

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18 pages, 11532 KB

Open AccessArticle

A Polyhydroxybutyrate-Supported Xerogel Biosensor for Rapid BOD Mapping and Integration with Satellite Data for Regional Water Quality Assessment

by George Gurkin, Alexey Efremov, Irina Koryakina, Roman Perchikov, Anna Kharkova, Anastasia Medvedeva, Bruno Fabiano, Andrea Pietro Reverberi and Vyacheslav Arlyapov

Gels 2025, 11(11), 849; https://doi.org/10.3390/gels11110849 (registering DOI) - 24 Oct 2025

Abstract

The growing threat of organic pollution to surface waters necessitates the development of rapid and scalable monitoring tools that transcend the limitations of the standard 5-day biochemical oxygen demand (BOD₅) test. This study presents a novel approach by developing a highly [...] Read more.

The growing threat of organic pollution to surface waters necessitates the development of rapid and scalable monitoring tools that transcend the limitations of the standard 5-day biochemical oxygen demand (BOD₅) test. This study presents a novel approach by developing a highly stable and rapid BOD biosensor based on the microorganism Paracoccus yeei, immobilized within a sol–gel-derived xerogel matrix synthesized on a polyhydroxybutyrate (PHB) substrate. The PHB-supported xerogel significantly enhanced microbial viability and sensor stability. This biosensor demonstrated a correlation (R² = 0.93) with the standard BOD₅ method across 53 diverse water samples from the Tula region, Russia, providing precise results in just 5 min. The second pillar of our methodology involved analyzing multi-year Landsat satellite imagery via the Global Surface Water Explorer to map hydrological changes and identify zones of potential anthropogenic impact. The synergy of rapid ground-truth biosensor measurements and remote sensing analysis enabled a comprehensive spatial assessment of water quality, successfully identifying and ranking pollution sources, with wastewater discharges and agro-industrial facilities constituting the most significant factors. This work underscores the high potential of PHB–xerogel composites as efficient immobilization matrices and establishes a powerful, scalable framework for regional environmental monitoring by integrating advanced biosensor technology with satellite observation. Full article

(This article belongs to the Special Issue Gel-Based Materials for Sensing and Monitoring)

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11 pages, 489 KB

Open AccessArticle

Effect of Reaction Time of TGase on the Water-Holding Capacity and Gel Properties of Reduced-Fat and Reduced-Sodium Chicken Meat Batters

by Dongyang Zhu, Ke Xu, Zhuangli Kang, Bo Luo and Kun Fang

Gels 2025, 11(11), 848; https://doi.org/10.3390/gels11110848 - 23 Oct 2025

Abstract

In this paper, the effects of TGase reaction times (0, 6, 12, 18, and 24 h) at 4 °C on the solubility, emulsion stability, cooking yield, gel properties and water distribution of reduced-fat and reduced-sodium chicken meat batter were studied. The results showed [...] Read more.

In this paper, the effects of TGase reaction times (0, 6, 12, 18, and 24 h) at 4 °C on the solubility, emulsion stability, cooking yield, gel properties and water distribution of reduced-fat and reduced-sodium chicken meat batter were studied. The results showed that the reaction time had a significant effect on the water fluidity and quality characteristics of reduced-fat and reduced-sodium chicken meat batter. The solubility, cooking yield and water-holding capacity of salt-soluble proteins initially increased then decreased with extended reaction time, reaching maximum values of 65.50%, 96.13% and 96.00%, respectively, at 12 h. The emulsifying stability and textural properties initially increased, then decreased with extended reaction time (p < 0.05), achieving optimal levels at 12 h. In contrast, the initial relaxation time of T21 and T22 initially decreased (p < 0.05) and then increased (p < 0.05) with longer reaction times; the minimum values were 12 h, especially the free water decreased from 17.97% to 6.69%, consistent with the finding on water-holding capacity and gel properties. In conclusion, the reaction time of the TGase affected its effect on improving the gel effect of reduced-fat and reduced-sodium chicken meat batter, and the best effect was achieved at 12 h. Full article

(This article belongs to the Special Issue Advanced Gels in the Food System)

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19 pages, 3706 KB

Open AccessArticle

Synergy of Low Injection Resistance and High Plugging in a High-Strength Nanobentonite/Amphoteric Polymer Gel

by Huaizhu Liu, Guiqiang Fei, Kaiping Tian, Zhao Zhu, Donghang Ji and Houyong Luo

Gels 2025, 11(11), 847; https://doi.org/10.3390/gels11110847 - 23 Oct 2025

Abstract

Long-term water flooding development has exacerbated reservoir heterogeneity, and traditional polymer gels are unable to simultaneously meet the requirements of high injectability and strong plugging strength. If the viscosity of the polymer is high, its injectability will be poor; on the contrary the [...] Read more.

Long-term water flooding development has exacerbated reservoir heterogeneity, and traditional polymer gels are unable to simultaneously meet the requirements of high injectability and strong plugging strength. If the viscosity of the polymer is high, its injectability will be poor; on the contrary the viscosity is low, the plugging strength will be poor, which severely restricts the oil recovery effect. This study synthesized an NBAP through free radical polymerization followed by a substitution reaction, and a plugging system (NBAP-B1) was subsequently formed by combining the polymer with a Cr³⁺ crosslinking agent. Rheological experiments demonstrated that the system exhibited significant shear thinning behavior, as well as excellent temperature and salt resistance. Gelation experiments indicated that the NBAP-B1 system featured controllable gelation time (20~150 h) and high gelation strength (J grade), along with excellent resistance to both high temperature and high salinity. Microscopic analysis revealed that the gel formed by NBAP-B1 possessed a dense and uniform three-dimensional network structure. Injection and plugging experiments demonstrated that NBAP-B1 exhibited optimal injectability and outstanding plugging performance. Additionally, profile control and displacement tests revealed a 18.37% enhancement in oil recovery efficiency by water flooding after the application of NBAP-B1 for conformance control. Collectively, these results demonstrate that the NBAP exhibits significantly superior performance compared to single component systems. It combines excellent injectability with high strength plugging capability, offering an effective approach for enhancing oil recovery in low permeability reservoirs. Full article

(This article belongs to the Special Issue Applications of Gels for Enhanced Oil Recovery)

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33 pages, 2311 KB

Open AccessReview

Cell Membrane- and Vesicle-Based Bionic Nanodrugs: Applications in Central Nervous System Diseases and Exploration of Nasal–Cerebral Delivery

by Fan Ding, Runzhe Hou, Bing Han and Xuexun Fang

Gels 2025, 11(11), 846; https://doi.org/10.3390/gels11110846 - 22 Oct 2025

Abstract

Central nervous system (CNS) diseases exhibit high incidence rates, and the blood–brain barrier (BBB) poses a major obstacle to drug delivery. Conventional drug delivery methods not only show limited therapeutic efficacy but also cause significant side effects. Intranasal administration offers a new strategy [...] Read more.

Central nervous system (CNS) diseases exhibit high incidence rates, and the blood–brain barrier (BBB) poses a major obstacle to drug delivery. Conventional drug delivery methods not only show limited therapeutic efficacy but also cause significant side effects. Intranasal administration offers a new strategy for CNS therapy by bypassing the BBB through the unique nasal-brain pathway, while nanodrug delivery systems (NDDSs) can improve drug delivery efficiency. On this basis, biomimetic drug delivery systems (BDDSs) based on cell membrane structure have been developed. The combination of nanoparticles modified by cell membranes or cell membrane-derived vesicles with carriers such as hydrogels creates a drug delivery system that utilizes a unique transnasal-to-brain pathway, opening new avenues for treating CNS disorders. This paper systematically reviews the classification, characteristics, and preparation strategies of BDDSs, while analyzing the anatomical pathways and physiological mechanisms of nasal–cerebral delivery. Furthermore, it delves into the biogenesis mechanisms of extracellular vesicles (EVs) and bacterial extracellular vesicles (BEVs). For CNS disorders, including glioblastoma multiforme (GBM), ischemic stroke (IS), Alzheimer’s disease (AD), and Parkinson’s disease (PD), this paper presents diverse applications and challenges of BDDSs in nasal–cerebral delivery. Full article

(This article belongs to the Section Gel Applications)

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19 pages, 5810 KB

Open AccessArticle

Bilayer Biomimetic Scaffolds Loaded with Mesenchymal Stem Cell Secretomes Promote Diabetic Wound Healing

by Fangling Shen, Yiting Chen, Hongwen Li, Qi Zhang, Qixiong Ji, Linyuan Zou, Zhe Wang, Zhengyao Wu, Shengkai Yu, Hua Zhang and Qin Song

Gels 2025, 11(11), 845; https://doi.org/10.3390/gels11110845 - 22 Oct 2025

Abstract

Diabetic ulcers are among the most common and challenging complications of diabetes mellitus, and effective therapeutic strategies remain elusive. While stem cell secretome (SCS)-based therapy has attracted considerable attention due to its regenerative potential, its direct application is hindered by low bioavailability and [...] Read more.

Diabetic ulcers are among the most common and challenging complications of diabetes mellitus, and effective therapeutic strategies remain elusive. While stem cell secretome (SCS)-based therapy has attracted considerable attention due to its regenerative potential, its direct application is hindered by low bioavailability and rapid diffusion at the wound site. To address these limitations, we designed a bilayer bacterial cellulose–gelatin (Bi-BCG) scaffold inspired by the hierarchical structure of native skin. This scaffold features a compact bacterial cellulose (BC) upper layer with nanoscale porosity and a porous BCG lower layer with pore sizes of ~52 μm, optimized for SCS delivery. The Bi-BCG scaffold demonstrated a water vapor transmission rate of 2384 g/(m²·24 h) and exhibited significantly improved SCS retention capacity while maintaining high fluid absorption, outperforming monolayer BCG scaffolds. Functionally, human umbilical cord-derived mesenchymal stem cell (hUCMSCs)-derived secretomes significantly enhanced the proliferation (by up to 70.7%) and migration of skin fibroblasts under high-glucose conditions, promoted vascular endothelial cell proliferation (increasing Ki-67+ cells from 25.87% to 46.89%) and angiogenic network formation, and effectively suppressed macrophage-mediated inflammatory responses and oxidative stress. In vivo, the combination of SCSs with the Bi-BCG scaffold exhibited a clear synergistic effect, achieving a wound closure rate of 78.8% by day 10 and promoting superior structural restoration with well-organized collagen deposition, outperforming either treatment alone. These findings underscore the potential of the Bi-BCG scaffold combined with SCSs as an effective strategy for enhancing diabetic wound healing. Full article

(This article belongs to the Special Issue Advanced Hydrogels for Regenerative Medicine and Tissue Engineering (3rd Edition))

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33 pages, 3511 KB

Open AccessReview

Recent Advances in Dielectric Elastomer Actuator-Based Soft Robots: Classification, Applications, and Future Perspectives

by Shuo Li, Zhizheng Gao, Wenguang Yang, Ruiqian Wang and Lei Zhang

Gels 2025, 11(11), 844; https://doi.org/10.3390/gels11110844 - 22 Oct 2025

Abstract

With the growing application of soft robot technology in complex, dynamic environments, the limitations of traditional rigid robots have become increasingly prominent, urgently demanding novel soft actuation technologies. Dielectric elastomer actuators (DEAs) have gradually emerged as a research focus in soft robotics due [...] Read more.

With the growing application of soft robot technology in complex, dynamic environments, the limitations of traditional rigid robots have become increasingly prominent, urgently demanding novel soft actuation technologies. Dielectric elastomer actuators (DEAs) have gradually emerged as a research focus in soft robotics due to their high energy density, rapid response, low noise, and excellent compliance. This paper systematically reviews the research progress of DEA-based soft robots over the past decade. Using classification and comparative analysis, DEAs are categorized into four basic types according to their initial shape—planar, saddle-shaped, cylindrical, and conical—with detailed elaboration on their working principles, structural features, and typical applications. Furthermore, from two major application scenarios (underwater and terrestrial), this paper analyzes the adaptability of various DEAs in robot design and corresponding optimization strategies and summarizes their performance and research challenges in bionic propulsion, multi-modal motion, and environmental adaptability. Finally, it provides the prospective future research directions of DEAs in material development, structural design, intelligent control, and system integration, providing theoretical support and technical references for their wide application in fields such as medical treatment, detection, and human–robot interaction. Full article

(This article belongs to the Special Issue Gel-Based Materials for Intelligent Sensors and Self-Powered Nanogenerators)

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18 pages, 1125 KB

Open AccessArticle

Nutritional and Techno-Functional Properties of Ultrasound-Assisted Moringa oleifera Leaf Protein Concentrate with Potential Applications in Food Gels

by Eunice Tranquilino-Rodríguez, Estefanía Bautista-Durán, José Juan Virgen-Ortiz, Ma. Guadalupe Garnica-Romo, Osvaldo Alvarez-Cortés, Gabriela Monserrat Ochoa-Manzo and Héctor Eduardo Martínez-Flores

Gels 2025, 11(11), 843; https://doi.org/10.3390/gels11110843 - 22 Oct 2025

Abstract

Moringa oleifera leaves are a protein-rich source containing all essential amino acids and offering high nutritional value. Ultrasound-assisted extraction (UAE) has emerged as an efficient method to improve protein recovery while enhancing the structural and functional properties of plant proteins. This study aimed [...] Read more.

Moringa oleifera leaves are a protein-rich source containing all essential amino acids and offering high nutritional value. Ultrasound-assisted extraction (UAE) has emerged as an efficient method to improve protein recovery while enhancing the structural and functional properties of plant proteins. This study aimed to improve protein extraction from M. oleifera leaves using UAE and to characterize the nutritional composition and gel-related properties of the resulting protein concentrate. Chosen conditions were a solubilization pH of 11.68, 20 min of ultrasound treatment, and precipitation at pH 4.5, resulting in an extraction yield of 79.90% and protein content of 53.97%. Moringa oleifera leaf flour (MOF) contained 29.38% protein, 37.98% dietary fiber, and high mineral levels (1751.85 mg/100 g of calcium; 512.55 mg/100 g of magnesium). Compared with MOF, the M. oleifera protein concentrate (MOPC) showed a 21.4% increase in essential amino acids, with leucine and lysine being the most abundant. Functionally, MOPC exhibited 24.26% solubility at pH 2, complete gelation at pH 8, 58.66% emulsifying capacity with 79.52% stability at pH 10, and 21.11% foaming capacity with 94.44% stability at pH 2. The gel-forming ability was the most promising characteristic, highlighting the potential of MOPC as a natural structuring agent in gel-based food systems and functional formulations. Full article

(This article belongs to the Special Issue Gels in Food Systems: Ingredients for Health, Sustainability and Industrial Innovation)

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Gels, Volume 11, Issue 11 (November 2025) – 9 articles

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