Gels

17 pages, 1448 KiB

Open AccessReview

Hydrogel-Based Innovations in Carpal Tunnel Syndrome: Bridging Pathophysiological Complexities and Translational Therapeutic Gaps

by Venera Cristina Dinescu, Liviu Martin, Marius Bica, Ramona Constantina Vasile, Andrei Gresita, Marius Bunescu, Mihai Andrei Ruscu, Madalina Aldea and Alexandra Daniela Rotaru-Zavaleanu

Gels 2025, 11(1), 52; https://doi.org/10.3390/gels11010052 - 9 Jan 2025

Abstract

Carpal Tunnel Syndrome (CTS) is a prevalent neuropathic disorder caused by chronic compression of the median nerve, leading to sensory and motor impairments. Conventional treatments, such as corticosteroid injections, wrist splinting, and surgical decompression, often fail to provide adequate outcomes for chronic or [...] Read more.

Carpal Tunnel Syndrome (CTS) is a prevalent neuropathic disorder caused by chronic compression of the median nerve, leading to sensory and motor impairments. Conventional treatments, such as corticosteroid injections, wrist splinting, and surgical decompression, often fail to provide adequate outcomes for chronic or recurrent cases, emphasizing the need for innovative therapies. Hydrogels, highly biocompatible three-dimensional biomaterials with customizable properties, hold significant potential for CTS management. Their ability to mimic the extracellular matrix facilitates localized drug delivery, anti-adhesion barrier formation, and tissue regeneration. Advances in hydrogel engineering have introduced stimuli-responsive systems tailored to the biomechanical environment of the carpal tunnel, enabling sustained therapeutic release and improved tissue integration. Despite these promising developments, hydrogel applications for CTS remain underexplored. Key challenges include the absence of CTS-specific preclinical models and the need for rigorous clinical validation. Addressing these gaps could unlock the full potential of hydrogel-based interventions, which offer minimally invasive, customizable solutions that could improve long-term outcomes and reduce recurrence rates. This review highlights hydrogels as a transformative approach to CTS therapy, advocating for continued research to address translational barriers. These innovations have the potential to redefine the treatment landscape, significantly enhancing patient care and quality of life. Full article

(This article belongs to the Special Issue Advances in Hydrogels for Biomedical Applications)

► Show Figures

Figure 1

18 pages, 4984 KiB

Open AccessArticle

Development of Extrudable Hydrogels Based on Carboxymethyl Cellulose–Gelatin Complex Coacervates

by Hamid Gharanjig, Hossein Najaf Zadeh, Campbell Stevens, Pram Abhayawardhana, Tim Huber and Ali Reza Nazmi

Gels 2025, 11(1), 51; https://doi.org/10.3390/gels11010051 - 8 Jan 2025

Abstract

This study investigates the 3D extrusion printing of a carboxymethyl cellulose (CMC)–gelatin complex coacervate system. Various CMC–gelatin coacervate hydrogels were prepared and analyzed to achieve this goal. The impact of the CMC–gelatin ratio, pH, and total biopolymer concentration on coacervation formation and rheological [...] Read more.

This study investigates the 3D extrusion printing of a carboxymethyl cellulose (CMC)–gelatin complex coacervate system. Various CMC–gelatin coacervate hydrogels were prepared and analyzed to achieve this goal. The impact of the CMC–gelatin ratio, pH, and total biopolymer concentration on coacervation formation and rheological properties was evaluated to characterize the printability of the samples. Turbidity results indicated that the molecular interactions between gelatin and CMC biopolymers are significantly pH-dependent, occurring within the range of pH 3.7 to pH 5.6 for the tested compositions. Confocal Laser Scanning Microscopy (CLSM) confirmed the presence of coacervates as spherical particles within the optimal coacervation range. Scanning electron microscopy micrographs supported the CLSM findings, revealing greater porosity within this optimal pH range. Rheological characterization demonstrated that all CMC–gelatin hydrogels exhibited pseudoplastic behavior, with an inverse correlation between increased coacervation and decreased shear viscosity. Additionally, the coacervates displayed lower tackiness compared to gelatin hydrogels, with the maximum tackiness normal force for various CMC–gelatin ratios ranging from 1 to 15 N, notably lower than the 29 N observed for gelatin hydrogels. Mixtures with CMC–gelatin ratios of 1:15 and 1:20 exhibited the best shear recovery behavior, maintaining higher strength after shear load. The maximum strength of the CMC–gelatin coacervate system was found at a biopolymer concentration of 6%. However, lower biopolymer content allowed for consistent extrusion. Importantly, all tested samples were successfully extruded at 22 ± 2 °C, with the 1:15 biopolymer ratio yielding the most consistent printed quality. Our research highlights the promise of the CMC–gelatin coacervate system for 3D printing applications, particularly in areas that demand precise material deposition and adjustable properties. Full article

(This article belongs to the Special Issue Cellulose-Based Gels: Synthesis, Properties, and Applications)

► Show Figures

Graphical abstract

13 pages, 1308 KiB

Open AccessReview

Utilisation of High Molecular Weight and Ultra-High Molecular Weight Hyaluronan in Management of Glioblastoma

by Alex-Adrian Salagean, Cezara-Anca-Denisa Moldovan and Mark Slevin

Gels 2025, 11(1), 50; https://doi.org/10.3390/gels11010050 - 8 Jan 2025

Abstract

HA (hyaluronan) has been considered in recent years as a naturally occurring modifiable gel-like scaffold that has the capability to absorb and release drugs over an extended period of time making it suitable as a potential chemotherapeutic delivery agent. Considering the limited treatment [...] Read more.

HA (hyaluronan) has been considered in recent years as a naturally occurring modifiable gel-like scaffold that has the capability to absorb and release drugs over an extended period of time making it suitable as a potential chemotherapeutic delivery agent. Considering the limited treatment options available in the treatment of glioblastoma, in this review, we discuss the novel utilisation of ultra-high molecular weight HA—originally identified as a mechanism for maintaining longevity in the naked mole-rat—as both a protective and extracellular matrix-optimizing colloidal scaffold, and a means to deliver therapy in resected brain tumours. The unique properties of this unique form of HA cross-linked gel indicate potential future use in the prevention and treatment of both proliferative-based and inflammation-driven disease. Full article

(This article belongs to the Special Issue Recent Advances in Biopolymer Gels)

► Show Figures

Figure 1

16 pages, 4236 KiB

Open AccessArticle

Development of Scalable Elastic Gelatin Hydrogel Films Crosslinked with Waterborne Polyurethane for Enhanced Mechanical Properties and Strain Recovery

by Soon Mo Choi, Eun Joo Shin, Sun Mi Zo, Madhusudana Rao Kummara, Chul Min Kim, Anuj Kumar, Han Jo Bae, Ankur Sood and Sung Soo Han

Gels 2025, 11(1), 49; https://doi.org/10.3390/gels11010049 - 8 Jan 2025

Abstract

Exploiting novel crosslinking chemistry, this study pioneers the use of waterborne polyurethane (WPU) to chemically crosslink porcine-derived gelatin, producing enhanced gelatin hydrogel films through a solvent-casting method. Our innovative approach harnesses the reactive isocyanate groups of WPU, coupling them effectively with gelatin’s hydroxyl [...] Read more.

Exploiting novel crosslinking chemistry, this study pioneers the use of waterborne polyurethane (WPU) to chemically crosslink porcine-derived gelatin, producing enhanced gelatin hydrogel films through a solvent-casting method. Our innovative approach harnesses the reactive isocyanate groups of WPU, coupling them effectively with gelatin’s hydroxyl and primary amino groups to form robust urea and urethane linkages within the hydrogel matrix. This method not only preserves the intrinsic elasticity of polyurethane but also significantly augments the films’ tensile strength and strain. Comprehensive characterizations of these hydrogel films and pre-formed hydrogel reaction mixtures were conducted using viscosity measurements, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and the universal testing machine (UTM) for tensile-recovery assessments, alongside evaluations of their biocompatibility. The results demonstrated a reduction in pore size with an increase in WPU concentration from 2 to 6% in the developed hydrogels with a decrease in the equilibrium swelling ratio from 15% to 9%, respectively. Further, hydrogels with 6% WPU exhibited the highest tensile stress in both a dry and wet state. The gelatin hydrogel formed with 6% WPU blend also demonstrated the growth and proliferation of CCD-986K (fibroblast) and CCD-1102 (keratinocyte) cells for up to 5 days of co-culturing. The results indicate a notable enhancement in the mechanical properties and biocompatibility of gelatin hydrogels upon the introduction of WPU, positioning these films as superior candidates for biomedical applications such as tissue engineering and wound dressing. Full article

(This article belongs to the Special Issue Properties and Applications of Biomaterials Related to Gels (2nd Edition))

► Show Figures

Figure 1

12 pages, 2118 KiB

Open AccessArticle

Natural Bletilla striata Polysaccharide-Based Hydrogels for Accelerating Hemostasis

by Hui-Fang Lin, Yue-Yue Wang, Feng-Zhen Liu, Zi-Wei Yang, Hao Cui, Si-Yu Hu, Feng-He Li and Pei Pan

Gels 2025, 11(1), 48; https://doi.org/10.3390/gels11010048 - 8 Jan 2025

Abstract

Most of the existing hydrogel dressings have inadequacies in mechanical performance, biological activities, compatibility, or versatility, which results in the development of rapid, green, and cost-effective approaches for hydrogels in biochemical and biomedical applications becoming a top-priority task. Herein, inspired by the inherent [...] Read more.

Most of the existing hydrogel dressings have inadequacies in mechanical performance, biological activities, compatibility, or versatility, which results in the development of rapid, green, and cost-effective approaches for hydrogels in biochemical and biomedical applications becoming a top-priority task. Herein, inspired by the inherent bioactivity, water retention properties, and biocompatibility of natural polysaccharide hydrogels, we have prepared self-healing gels. Using Bletilla striata polysaccharide (BSP), carboxymethyl chitosan (CMCS), and borax via borate ester linkages, we created hemostatic and self-healing Chinese herbal medicine hydrogels in varying concentrations (2.5%, 3.0%, and 4.0%). A rotational rheometer was used to describe the hydrogels’ shape and rheological characteristics. At all concentrations, it was found that the hydrogels’ elastic modulus (G′) consistently and significantly outperformed their viscous modulus (G″), suggesting a robust internal structure. All of the hydrogels had cell viability levels as high as 100% and hemolysis rates below 1%, indicating the hydrogels’ outstanding biocompatibility. Furthermore, the hydrogels demonstrated superior hemostatic qualities in an in vivo mouse tail amputation model, as well as in in vitro coagulation tests. The results show that the hydrogel possesses excellent self-healing properties, as well as a good biocompatibility and hemostatic performance, thus paving the way for the development of a potential hemostatic green hydrogel. Full article

(This article belongs to the Special Issue Advancing Green Chemistry in Hydrogel Development: Design, Synthesis, and Characterization)

► Show Figures

Graphical abstract

29 pages, 4274 KiB

Open AccessReview

Role of Ionizing Radiation Techniques in Polymeric Hydrogel Synthesis for Tissue Engineering Applications

by Ion Călina, Maria Demeter, Anca Scărișoreanu, Awn Abbas and Muhammad Asim Raza

Gels 2025, 11(1), 47; https://doi.org/10.3390/gels11010047 - 8 Jan 2025

Abstract

Hydrogels are widely utilized in industrial and scientific applications owing to their ability to immobilize active molecules, cells, and nanoparticles. This capability has led to their growing use in various biomedical fields, including cell culture and transplantation, drug delivery, and tissue engineering. Among [...] Read more.

Hydrogels are widely utilized in industrial and scientific applications owing to their ability to immobilize active molecules, cells, and nanoparticles. This capability has led to their growing use in various biomedical fields, including cell culture and transplantation, drug delivery, and tissue engineering. Among the available synthesis techniques, ionizing-radiation-induced fabrication stands out as an environmentally friendly method for hydrogel preparation. In alignment with the current requirements for cleaner technologies, developing hydrogels using gamma and electron beam irradiation technologies represents a promising and innovative approach for their biomedical applications. A key advantage of these methods is their ability to synthesize homogeneous three-dimensional networks in a single step, without the need for chemical initiators or catalysts. Additionally, the fabrication process is controllable by adjusting the radiation dose and dose rate. Full article

(This article belongs to the Special Issue Novel Gels for Topical Applications)

► Show Figures

Graphical abstract

14 pages, 2066 KiB

Open AccessArticle

Textural, Color, and Sensory Analysis of Cookies Prepared with Hemp Oil-Based Oleogels

by Ana Leahu, Cristina Ghinea, Sorina Ropciuc and Cristina Damian

Gels 2025, 11(1), 46; https://doi.org/10.3390/gels11010046 - 7 Jan 2025

Abstract

The amount of saturated fat in cookies can be reduced by replacing margarine with oleogel, resulting in healthier products. In this study, the rheological and textural profile of cookies formulated with oleogel as the main margarine substitute was evaluated. Hemp seed vegetable oil [...] Read more.

The amount of saturated fat in cookies can be reduced by replacing margarine with oleogel, resulting in healthier products. In this study, the rheological and textural profile of cookies formulated with oleogel as the main margarine substitute was evaluated. Hemp seed vegetable oil was oleogelized with four types of waxes: beeswax (BW), carnauba wax (CW), candelilla wax (DW), rice bran wax (RW), and three oleogeling agents, sitosterol (S), pea protein (PP), and xanthan gum (XG), respectively. The textural and rheological properties of the oleogel dough samples were analyzed using the PertenTVT-6700 texturometer (Perten Instruments, Sweden) and the Haake rheometer. The results showed an increase in the hardness of cookie doughs with oleogels. The values of the elastic component (G′) and the viscous component (G″) increased, which means that the oleogels used affected the rheological behavior at 25 °C, causing an increase in the dough consistency. Sensory attributes, texture, and color parameters of cookies with oleogels were determined. The cookies’ hardness increased significantly from 4409.83 ± 0.13 g (control sample) to 7085.33 ± 0.15 g in the cookie sample prepared with hemp oil sitosterol oleogel, whereas the sample with candelilla wax had the lowest hardness value of 4048.09 ± 0.14 g. The color of the oleogel cookies was darker than that of the control cookies. The cookie sample with hemp oil and beeswax oleogel was the most appreciated by the evaluators among the oleogel cookie samples. The findings suggest that hemp seed oil oleogel is an effective fat substitute in cookies, promoting the application of this vegetable oil in food products. Full article

(This article belongs to the Special Issue Oleogels, Bigels, and Emulgels: Fabrication, Application and Research Trends)

► Show Figures

Figure 1

26 pages, 5365 KiB

Open AccessArticle

Characterization and Machine Learning-Driven Property Prediction of a Novel Hybrid Hydrogel Bioink Considering Extrusion-Based 3D Bioprinting

by Rokeya Sarah, Kory Schimmelpfennig, Riley Rohauer, Christopher L. Lewis, Shah M. Limon and Ahasan Habib

Gels 2025, 11(1), 45; https://doi.org/10.3390/gels11010045 - 7 Jan 2025

Abstract

The field of tissue engineering has made significant advancements with extrusion-based bioprinting, which uses shear forces to create intricate tissue structures. However, the success of this method heavily relies on the rheological properties of bioinks. Most bioinks use shear-thinning. While a few component-based [...] Read more.

The field of tissue engineering has made significant advancements with extrusion-based bioprinting, which uses shear forces to create intricate tissue structures. However, the success of this method heavily relies on the rheological properties of bioinks. Most bioinks use shear-thinning. While a few component-based efforts have been reported to predict the viscosity of bioinks, the impact of shear rate has been vastly ignored. To address this gap, our research presents predictive models using machine learning (ML) algorithms, including polynomial fit (PF), decision tree (DT), and random forest (RF), to estimate bioink viscosity based on component weights and shear rate. We utilized novel bioinks composed of varying percentages of alginate (2–5.25%), gelatin (2–5.25%), and TEMPO-Nano fibrillated cellulose (0.5–1%) at shear rates from 0.1 to 100 s⁻¹. Our study analyzed 169 rheological measurements using 80% training and 20% validation data. The results, based on the coefficient of determination (R2) and mean absolute error (MAE), showed that the RF algorithm-based model performed best: [(R2, MAE) RF = (0.99, 0.09), (R2, MAE) PF = (0.95, 0.28), (R2, MAE) DT = (0.98, 0.13)]. These predictive models serve as valuable tools for bioink formulation optimization, allowing researchers to determine effective viscosities without extensive experimental trials to accelerate tissue engineering. Full article

(This article belongs to the Special Issue State-of-the Art Gel Research in USA)

► Show Figures

Graphical abstract

21 pages, 7145 KiB

Open AccessArticle

Studying the Size-Dependence of Graphene Nanoplatelets (GNPs) in the Final Properties of Polyurethane Aerogels: Thermal Insulation and Mechanical Strength

by Jaime Lledó, Judith Martín-de León, Tomás E. Gómez Álvarez-Arenas, Miguel Ángel Rodríguez-Pérez and Beatriz Merillas

Gels 2025, 11(1), 44; https://doi.org/10.3390/gels11010044 - 7 Jan 2025

Abstract

In the present work, the influence of the addition of graphene nanoplatelets presenting different dimensions on polyurethane–polyisocyanurate aerogel structure and properties has been studied. The obtained aerogels synthesized through a sol–gel method have been fully characterized in terms of density, porosity, specific surface [...] Read more.

In the present work, the influence of the addition of graphene nanoplatelets presenting different dimensions on polyurethane–polyisocyanurate aerogel structure and properties has been studied. The obtained aerogels synthesized through a sol–gel method have been fully characterized in terms of density, porosity, specific surface area, mechanical stiffness, thermal conductivity, and speed of sound. Opacified aerogels showing high porosity (>92%) and low densities (78–98 kg/m³) have been produced, and the effect of the size and content of graphene nanoplatelets has been studied. It has been observed that formulations with less than 5 wt.% of graphene nanoplatelets larger than 2 microns can effectively reduce the total thermal conductivity by absorption and scattering of the infrared radiation, reducing the heat transfer by this mechanism. The resulting opacified samples are highly insulating materials, with thermal conductivities less than 18 mW/m·K. Moreover, it has been observed that smaller particles with ca. 200 nm of average length can promote an increase in the elastic modulus, therefore obtaining stiffer aerogels, combined with thermal conductivities lower than 20 mW/m·K. Results have been studied in detail, providing a further understanding of the mechanisms for improving the final properties of these materials, making them more suitable for industrial applications. Full article

(This article belongs to the Special Issue Advances in Synthetic and Bio-Based Aerogels: Mechanical Properties, Thermal Insulation, and Environmental Remediation (2nd Edition))

► Show Figures

Graphical abstract

17 pages, 3948 KiB

Open AccessArticle

Enhancing the Oxidative Stability of Beeswax–Canola Oleogels: Effects of Ascorbic Acid and Alpha-Tocopherol on Their Physical and Chemical Properties

by Sonia Millao, Marcela Quilaqueo, Ingrid Contardo and Mónica Rubilar

Gels 2025, 11(1), 43; https://doi.org/10.3390/gels11010043 - 7 Jan 2025

Abstract

The choice of antioxidant to be used in the formulation of an oleogel is crucial to determine its oxidative stability and functionality, as these factors can also affect the physical, chemical, and rheological properties of the oleogel. In this study, the effect of [...] Read more.

The choice of antioxidant to be used in the formulation of an oleogel is crucial to determine its oxidative stability and functionality, as these factors can also affect the physical, chemical, and rheological properties of the oleogel. In this study, the effect of two antioxidants (ascorbic acid, AA, and alpha-tocopherol, AT) and their concentration (0.01, 0.02, and 0.03%) on the physical and chemical properties of beeswax and canola oil oleogels were evaluated. The results show that the type and concentration of antioxidants did not affect the thermal properties of the samples, and in FTIR analyses, no noticeable changes in spectra patterns are observed. Rheological analyses showed that the oleogels containing AA exhibited higher elasticity and resistance to deformation. Accelerated oxidative stability tests (storage at 50 °C and the Rancimat test) showed that AA effectively delayed oxidation. The induction time increased by 2.61-fold at higher concentrations, while AT did not significantly affect oxidation resistance. Overall, it was observed that AA improved oleogel firmness and OBC (up to 1.75-fold and 2.8%, respectively), whereas AT resulted in a softer and less stable gel structure. These results show the importance of antioxidant selection, indicating that hydrophilic antioxidants have promising applications in the formulation of beeswax oleogels. Full article

(This article belongs to the Special Issue Functionality of Oleogels and Bigels in Foods)

► Show Figures

Figure 1

20 pages, 6417 KiB

Open AccessArticle

Polydeoxynucleotide-Loaded Visible Light Photo-Crosslinked Gelatin Methacrylate Hydrogel: Approach to Accelerating Cartilage Regeneration

by Sunjae Park, Youngjun Son, Jonggyu Park, Soyoon Lee, Na-Hyeon Kim, Se-Na Jang, Tae-Woong Kang, Jeong-Eun Song and Gilson Khang

Gels 2025, 11(1), 42; https://doi.org/10.3390/gels11010042 - 7 Jan 2025

Abstract

Articular cartilage faces challenges in self-repair due to the lack of blood vessels and limited chondrocyte concentration. Polydeoxyribonucleotide (PDRN) shows promise for promoting chondrocyte growth and cartilage regeneration, but its delivery has been limited to injections. Continuous PDRN delivery is crucial for effective [...] Read more.

Articular cartilage faces challenges in self-repair due to the lack of blood vessels and limited chondrocyte concentration. Polydeoxyribonucleotide (PDRN) shows promise for promoting chondrocyte growth and cartilage regeneration, but its delivery has been limited to injections. Continuous PDRN delivery is crucial for effective cartilage regeneration. This study explores using gelatin methacrylate (gelMA) hydrogel, crosslinked with visible light and riboflavin 5′-phosphate sodium (RF) as a photoinitiator, for sustained PDRN release. GelMA hydrogel’s synthesis was confirmed through spectrophotometric techniques, demonstrating successful methacrylate group incorporation. PDRN-loaded gelMA hydrogels displayed varying pore sizes, swelling ratios, degradation rates, and mechanical properties based on gelMA concentration. They showed sustained PDRN release and biocompatibility, with the 14% gelMA-PDRN composition performing best. Glycosaminoglycan (GAG) activity was higher in PDRN-loaded hydrogels, indicating a positive effect on cartilage formation. RT-PCR analysis revealed increased expression of cartilage-specific genes (COL2, SOX9, AGG) in gelMA-PDRN. Histological assessments in a rabbit cartilage defect model demonstrated superior regenerative effects of gelMA-PDRN hydrogels. This study highlights the potential of gelMA-PDRN hydrogels in cartilage tissue engineering, providing a promising approach for effective cartilage regeneration. Full article

(This article belongs to the Special Issue Hydrogel for Tissue Engineering and Biomedical Therapeutics)

► Show Figures

Figure 1

13 pages, 1437 KiB

Open AccessArticle

Permeation Enhancer in Microemulsions and Microemulsion-Based Gels: A Comparison of Diethylene Glycol Monoethyl Ether and Oleyl Alcohol

by Sujata Pandey and Gabriella Baki

Gels 2025, 11(1), 41; https://doi.org/10.3390/gels11010041 - 5 Jan 2025

Abstract

Microemulsions have been commonly used with various permeation enhancers to improve permeability through the skin. The purpose of this study was to compare the release and permeation ability of two commonly used permeation enhancers—diethylene glycol monoethyl ether (DGME) and oleyl alcohol—by the changes [...] Read more.

Microemulsions have been commonly used with various permeation enhancers to improve permeability through the skin. The purpose of this study was to compare the release and permeation ability of two commonly used permeation enhancers—diethylene glycol monoethyl ether (DGME) and oleyl alcohol—by the changes in oil composition, the addition of a gelling agent, and water content using ibuprofen as a model drug. Four microemulsions were formulated, selection was based on ternary phase diagrams, and physicochemical properties were evaluated. The release and permeation of the microemulsion formulations were performed in vitro by Franz cell studies on a regenerated cellulose membrane and a Strat-M^® membrane, respectively, and the amount of ibuprofen permeated and released was analyzed by high-performance liquid chromatography (HPLC). All four microemulsions were compatible with the skin pH, and the average pH ranged from 4.9 to 5.6. The average droplet size of the microemulsions ranged from 119.8 to 153.3 nm. Drug release was significantly the highest from the gel-based microemulsions (59% and 64%, p < 0.05). However, there was a fourfold difference in drug permeation from these gels—a significantly higher permeation from the microemulsion-gel containing oleic acid and oleyl alcohol compared to the DGME formulation. These results indicated that the microemulsion-gel with oleyl alcohol as the permeation enhancer could be a preferable formulation approach for the topical administration of ibuprofen. These results highlight the need for optimization of the microemulsion formulation to confirm the permeation-enhancing effects of chosen permeation enhancers despite being a well-known permeation enhancer. Full article

(This article belongs to the Special Issue Recent Research on Medical Hydrogels)

► Show Figures

Figure 1

21 pages, 3947 KiB

Open AccessArticle

Exploring Methacrylated Gellan Gum 3D Bioprinted Patches Loaded with Tannic Acid or L-Ascorbic Acid as Potential Platform for Wound Dressing Application

by Federica Scalia, Alessandra Maria Vitale, Domiziana Picone, Noemi De Cesare, Maria Swiontek Brzezinska, Beata Kaczmarek-Szczepanska, Alfredo Ronca, Barbara Zavan, Fabio Bucchieri, Marta Anna Szychlinska and Ugo D’Amora

Gels 2025, 11(1), 40; https://doi.org/10.3390/gels11010040 - 5 Jan 2025

Abstract

To improve wound healing, advanced biofabrication techniques are proposed here to develop customized wound patches to release bioactive agents targeting cell function in a controlled manner. Three-dimensional (3D) bioprinted “smart” patches, based on methacrylated gellan gum (GGMA), loaded with tannic acid (TA) or [...] Read more.

To improve wound healing, advanced biofabrication techniques are proposed here to develop customized wound patches to release bioactive agents targeting cell function in a controlled manner. Three-dimensional (3D) bioprinted “smart” patches, based on methacrylated gellan gum (GGMA), loaded with tannic acid (TA) or L-ascorbic acid (AA) have been manufactured. To improve stability and degradation time, gellan gum (GG) was chemically modified by grafting methacrylic moieties on the polysaccharide backbone. GGMA patches were characterized through physicochemical, morphological and mechanical evaluation. Kinetics release and antioxidant potential of TA and AA as well as antimicrobial activity against common pathogens Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli in accordance with ISO 22196:2011 are reported. The cytocompatibility of the patches was demonstrated by direct and indirect tests on human dermal fibroblasts (HDF) as per ISO 10993. The positive effect of GGMA patches on cell migration was assessed through a wound healing assay. The results highlighted that the patches are cytocompatible, speed up wound healing and can swell upon contact with the hydration medium and release TA and AA in a controlled way. Overall, the TA- and AA-loaded GGMA patches demonstrated suitable mechanical features; no cytotoxicity; and antioxidant, antimicrobial and wound healing properties, showing satisfactory potential for wound dressing applications. Full article

(This article belongs to the Special Issue Gels in Medicine and Pharmacological Therapies (2nd Edition))

► Show Figures

Graphical abstract

14 pages, 4863 KiB

Open AccessArticle

Investigation of Chitosan-Based Hydrogels and Polycaprolactone-Based Electrospun Fibers as Wound Dressing Materials Based on Mechanical, Physical, and Chemical Characterization

by Barkin Aydin, Nihat Arol, Nimet Burak, Aybala Usta and Muhammet Ceylan

Gels 2025, 11(1), 39; https://doi.org/10.3390/gels11010039 - 4 Jan 2025

Abstract

The aim of this project is to fabricate fiber mats and hydrogel materials that constitute the two main components of a wound dressing material. The contributions of boric acid (BA) and zinc oxide (ZnO) to the physical and mechanical properties of polycaprolactone (PCL) [...] Read more.

The aim of this project is to fabricate fiber mats and hydrogel materials that constitute the two main components of a wound dressing material. The contributions of boric acid (BA) and zinc oxide (ZnO) to the physical and mechanical properties of polycaprolactone (PCL) is investigated. These materials are chosen for their antimicrobial and antifungal effects. Additionally, since chitosan forms brittle hydrogels, it is reinforced with polyvinyl alcohol (PVA) to improve ductility and water uptake properties. For these purposes, PCL, BA, ZnO, PVA, and chitosan are used in different ratios to fabricate nanofiber mats and hydrogels. Mechanical, physical, and chemical characteristics are examined. The highest elastic modulus and tensile strength are obtained from samples with 6% BA and 10% ZnO concentrations. ZnO-decorated fibers exhibit a higher elastic modulus than those with BA, though BA-containing fibers exhibit greater elongation before breakage. All fibers exhibit hydrophobic properties, which help to prevent biofilm formation. In compression tests, CS12 demonstrates the highest strength. Increasing the PVA content enhances ductility, while a higher concentration of chitosan results in a denser structure. This outcome is confirmed by FTIR and swelling tests. These findings highlight the optimal combinations of nanofibrous mats and hydrogels, offering guidance for future wound dressing designs that balance mechanical strength, water absorption, and antimicrobial properties. By stacking these nanofibrous mats and hydrogels in different orders, it is expected to achieve a wound care material that is suitable for various applications. The authors encourage experimentation with different configurations of these nanofiber and hydrogel stackings to observe their mechanical behavior under real-life conditions in future studies. Full article

(This article belongs to the Section Gel Analysis and Characterization)

► Show Figures

Figure 1

17 pages, 4521 KiB

Open AccessArticle

Evaluation of Carboxymethyl Cellulose/Gelatin Hydrogel-Based Dressing Containing Cefdinir for Wound Healing Promotion in Animal Model

by Zahra Soleimani, Hadi Baharifar, Najmeh Najmoddin and Kamyar Khoshnevisan

Gels 2025, 11(1), 38; https://doi.org/10.3390/gels11010038 - 4 Jan 2025

Abstract

The skin serves as a critical barrier against external pathogens, and its wound healing is a complex biological process that requires careful management to ensure optimal tissue regeneration. Hydrogels, a class of hydrophilic polymers, have emerged as promising materials for wound dressings due [...] Read more.

The skin serves as a critical barrier against external pathogens, and its wound healing is a complex biological process that requires careful management to ensure optimal tissue regeneration. Hydrogels, a class of hydrophilic polymers, have emerged as promising materials for wound dressings due to their biocompatibility, biodegradability, and ability to create a moist wound environment conducive to cell proliferation and migration. In this research, a hydrogel dressing containing cefdinir (Cef) was made from a combination of carboxymethyl cellulose (CMC) and gelatin (Gel) by a physical crosslinking method, and their physicochemical, mechanical, and biological properties were investigated. Results show that the addition of Cef does not cause a significant change in the morphology or the tensile strength of the wound dressing. The swelling and degradation rate of the hydrogel slightly increased in the presence of Cef. The presence of Cef enhanced antibacterial effects up to 2.5-fold against P. aeruginosa (35 mm), S. aureus (36 mm), and S. pyogenes (35 mm). The results of the cytotoxicity test showed the absence of cytotoxicity in both drug-containing and drug-free wound dressings, as well as a survival rate of over 75% in cells after 48 h. The drug-containing wound dressing accelerates the formation of the epidermis layer and the production of fibroblast cells, and as a result, accelerates the wound healing process. The percentage of wound healing on the ninth day of treatment for an untreated wound was 30%, while this percentage was 40% with a wound dressing without medicine and 60% with a wound dressing containing medicine, and on the fifteenth day of treatment, the wound treated with both wound dressings had more than 85% healing. As a result, it is possible to use CMC/Gel hydrogel polymeric wound dressing containing Cef as a wound dressing for wound healing, according to the desired physicochemical properties and biocompatibility. Full article

(This article belongs to the Special Issue Wound Healing and Other Biomedical Applications of Novel Gel Formulations)

► Show Figures

Graphical abstract

31 pages, 13954 KiB

Open AccessArticle

Kombucha Versus Vegetal Cellulose for Affordable Mucoadhesive (nano)Formulations

by Ioana Popa-Tudor, Naomi Tritean, Ștefan-Ovidiu Dima, Bogdan Trică, Marius Ghiurea, Anisoara Cimpean, Florin Oancea and Diana Constantinescu-Aruxandei

Gels 2025, 11(1), 37; https://doi.org/10.3390/gels11010037 - 4 Jan 2025

Abstract

Cellulose nanofibers gained increasing interest in the production of medical devices such as mucoadhesive nanohydrogels due to their ability to retain moisture (high hydrophilicity), flexibility, superior porosity and durability, biodegradability, non-toxicity, and biocompatibility. In this work, we aimed to compare the suitability of [...] Read more.

Cellulose nanofibers gained increasing interest in the production of medical devices such as mucoadhesive nanohydrogels due to their ability to retain moisture (high hydrophilicity), flexibility, superior porosity and durability, biodegradability, non-toxicity, and biocompatibility. In this work, we aimed to compare the suitability of selected bacterial and vegetal nanocellulose to form hydrogels for biomedical applications. The vegetal and bacterial cellulose nanofibers were synthesized from brewer’s spent grains (BSG) and kombucha membranes, respectively. Two hydrogels were prepared, one based on the vegetal and the other based on the bacterial cellulose nanofibers (VNC and BNC, respectively). VNC was less opaque and more fluid than BNC. The cytocompatibility and in vitro antioxidant activity of the nanocellulose-based hydrogels were investigated using human gingival fibroblasts (HGF-1, ATCC CRL-2014). The investigation of the hydrogel–mucin interaction revealed that the BNC hydrogel had an approx. 2× higher mucin binding efficiency than the VNC hydrogel at a hydrogel/mucin ratio (mg/mg) = 4. The BNC hydrogel exhibited the highest potential to increase the number of metabolically active viable cells (107.60 ± 0.98% of cytotoxicity negative control) among all culture conditions. VNC reduced the amount of reactive oxygen species (ROS) by about 23% (105.5 ± 2.2% of C−) in comparison with the positive control, whereas the ROS level was slightly higher (120.2 ± 3.9% of C−) following the BNC hydrogel treatment. Neither of the two hydrogels showed antibacterial activity when assessed by the diffusion method. The data suggest that the BNC hydrogel based on nanocellulose from kombucha fermentation could be a better candidate for cytocompatible and mucoadhesive nanoformulations than the VNC hydrogel based on nanocellulose from brewer’s spent grains. The antioxidant and antibacterial activity of BNC and both BNC and VNC, respectively, should be improved. Full article

(This article belongs to the Special Issue Advances in Cellulose-Based Hydrogels (3rd Edition))

► Show Figures

Figure 1

18 pages, 6392 KiB

Open AccessArticle

Polymer Gels Based on PAMAM Dendrimers Functionalized with Caffeic Acid for Wound-Healing Applications

by Ricardo I. Castro, Wendy Donoso, Franko Restovic, Oscar Forero-Doria and Luis Guzman

Gels 2025, 11(1), 36; https://doi.org/10.3390/gels11010036 - 4 Jan 2025

Abstract

The wound-healing process has usually been related to therapeutic agents with antioxidant properties. Among them, caffeic acid, a cinnamic acid derivative, stands out. However, the use of this natural product is affected by its bioavailability and half-life. Nowadays, different approaches are being taken [...] Read more.

The wound-healing process has usually been related to therapeutic agents with antioxidant properties. Among them, caffeic acid, a cinnamic acid derivative, stands out. However, the use of this natural product is affected by its bioavailability and half-life. Nowadays, different approaches are being taken to improve the above-mentioned characteristics, as many active surface groups are present in polyamidoamine (PAMAM) dendrimers; without the need for extra cross-linking agents, physical gels are created by interactions such as hydrogen bonds, van der Waals forces, or π–π interactions based on the modification of the surface. One of these is functionalization with dendrimers, such as the poly(amidoamine) (PAMAM) family. To evaluate the effectiveness of functionalizing caffeic acid with PAMAM dendrimers, the in vitro and in vivo wound-healing properties of gel-PAMAM G3 conjugated with caffeic acid (GPG3Ca) and its precursor, cinnamic acid (GPG3Cin), were studied. The results showed no cytotoxicity and wound-healing activity at a concentration of 20 μg/mL in HaCaT cells with the GPG3Ca. Additionally, the ability to activate molecular mediators of the healing process was evidenced. Furthermore, GPG3Ca potentiated the in vivo wound-healing process. The positive effects and lack of cytotoxicity at the used concentration of the synthesized GPG3Ca on the wound-healing process could position it as an effective agent for wound-healing treatment. Full article

(This article belongs to the Special Issue Recent Advances in Biopolymer Gels)

► Show Figures

Graphical abstract

16 pages, 4927 KiB

Open AccessArticle

Synergistic Antibacterial Action of Norfloxacin-Encapsulated G4 Hydrogels: The Role of Boronic Acid and Cyclodextrin

by Monica-Cornelia Sardaru, Irina Rosca, Simona Morariu, Elena-Laura Ursu and Alexandru Rotaru

Gels 2025, 11(1), 35; https://doi.org/10.3390/gels11010035 - 4 Jan 2025

Abstract

In this present study, we developed and characterized a series of supramolecular G4 hydrogels by integrating β-cyclodextrin (β-CD) and boronic acid linkers into a supramolecular matrix to enhance antibacterial activity against Staphylococcus aureus (S. aureus). We systematically investigated [...] Read more.

In this present study, we developed and characterized a series of supramolecular G4 hydrogels by integrating β-cyclodextrin (β-CD) and boronic acid linkers into a supramolecular matrix to enhance antibacterial activity against Staphylococcus aureus (S. aureus). We systematically investigated how varying the number of free boronic acid moieties (ranging from two to six), along with guanosine and β-CD content, influences both the structural integrity and antimicrobial efficacy of these materials. Comprehensive characterization using FTIR, circular dichroism, X-ray diffraction, SEM, AFM, and rheological measurements confirmed successful synthesis and revealed that higher boronic acid content correlated with a stronger, more organized network. The most effective hydrogel displayed an inhibition zone of 25 mm in disk diffusion assays, and was further explored as a drug delivery platform, with the aim to exploit the capacity of the free β-CD cavity of the hydrogels to incorporate hydrophobic drugs. Norfloxacin (Nfx), a poorly water-soluble antibiotic, was successfully encapsulated within the hydrogel matrix through the inclusion of complex formation with β-CD, improving its solubility and enabling sustained, targeted release. The Nfx-loaded hydrogel expanded the inhibition zone to 49 mm and completely eradicated S. aureus cells within 24 h, outperforming both the unloaded hydrogel and free Nfx. These results highlight the synergistic effect of boronic acid moieties and controlled drug release, underlining the potential of these hydrogels as versatile platforms for localized antimicrobial therapy, such as in wound dressings or implant coatings. Nevertheless, further in vivo studies and long-term stability assessments are needed to fully establish clinical relevance, safety, and scalability before these systems can be translated into routine healthcare applications. Full article

(This article belongs to the Special Issue Customizing Hydrogels: A Journey from Concept to End-Use Properties)

► Show Figures

Graphical abstract

15 pages, 4301 KiB

Open AccessArticle

Simultaneous Encapsulation of Probiotic Bacteria (Lactococcus lactis, and Lactiplantibacillus plantarum) in Calcium Alginate Hydrogels

by Marko Vinceković, Luna Maslov Bandić, Fabijan Oštarić, Marta Kiš, Nevijo Zdolec, Ivan Marić, Suzana Šegota, Hana Zelić and Nataša Mikulec

Gels 2025, 11(1), 34; https://doi.org/10.3390/gels11010034 - 3 Jan 2025

Abstract

Encapsulation in alginate hydrogel microspheres is an effective method for protecting and improving the survival of lactic acid bacteria in different environments. This research aims to expand the knowledge about the structure/property relationship of calcium alginate microspheres loaded with a mixture of autochthonous [...] Read more.

Encapsulation in alginate hydrogel microspheres is an effective method for protecting and improving the survival of lactic acid bacteria in different environments. This research aims to expand the knowledge about the structure/property relationship of calcium alginate microspheres loaded with a mixture of autochthonous probiotic bacteria (Lactococcus lactis and Lactiplantibacillus plantarum). A novel hydrogel formulation (FORMLAB) was prepared by ionic gelation and the molecular interactions between the FORMLAB constituents, surface morphology, structure, swelling degree, and release profile were characterized. The simultaneous encapsulation of two bacterial cultures in the same compartment does not diminish their viability. The binding of calcium ions to bacterial cells creates favorable conditions for the propagation of the encapsulated bacteria. The molecular interactions between the FORMLAB constituents are complex, involving mainly hydrogen bonds and electrostatic interactions. With a very high degree of swelling followed by low crosslinking, the surface of the microspheres covered with bacterial cells and diffusion through the hydrogel matrix allow for the delivery of probiotics at the right time. The findings suggest that bacterial cells are efficiently delivered from calcium alginate microspheres, offering promising applications in the development of functional foods, especially in cheese production. Full article

(This article belongs to the Special Issue Thixotropic Gels: Mechanisms, Functions and Applications)

► Show Figures

Graphical abstract

Journal Description

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI