Gels | November 2025 - Browse Articles

20 pages, 7037 KB

Open AccessArticle

Silica- and Titanium-poly(ethylene glycol) Hydrogels—Novel Matrices for Bacterial Cell Immobilization

by Ekaterina Filippova, Anton Zvonarev, Vasily Terentyev, Vasilina Farofonova, Valeriya Frolova, Tat’yana Khonina, Sergey Alferov and Daria Lavrova

Gels 2025, 11(11), 934; https://doi.org/10.3390/gels11110934 - 20 Nov 2025

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Abstract

For the first time, hydrogels based on silica- and titanium-poly(ethylene glycol) have been used for immobilization of Gram-negative bacteria (Escherichia coli MG1655) and Gram-positive bacteria (Rhodococcus qingshengii X5) in a one-step sol–gel synthesis. Vibrational spectroscopy and thermogravimetric analysis have [...] Read more.

For the first time, hydrogels based on silica- and titanium-poly(ethylene glycol) have been used for immobilization of Gram-negative bacteria (Escherichia coli MG1655) and Gram-positive bacteria (Rhodococcus qingshengii X5) in a one-step sol–gel synthesis. Vibrational spectroscopy and thermogravimetric analysis have confirmed the formation of amorphous hybrid structures with a predominance of organic components and metal-oxide grids. Encapsulation efficiencies were 72–77% for Si-PEG-based hydrogel and 50–54% for Ti-PEG. Antimicrobial activity tests revealed that Si-PEG was non-toxic, while Ti-PEG reduced cell viability by 50%. For the first time, an analysis of the morphological properties of immobilized bacterial cells revealed the formation of a thin Si-PEG-based hydrogel shell around each cell and a thick polymer layer on the bacterial surface when encapsulated within Ti-PEG-based hydrogels. The catalytic activity of the biocatalysts, as measured by the ATP content, remained at 84–93% for Si-PEG-based hydrogel, and decreased to 5% for Ti-PEG-based hydrogel. Biocatalysts based on encapsulated bacteria in a Si-PEG-based hydrogel demonstrate high sensitivity and stability. Si-PEG-based hydrogel exhibits high biocompatibility, making it suitable for the effective encapsulation of various bacterial types with a “cell-in-shell” structure. Full article

(This article belongs to the Special Issue Biobased Gels for Drugs and Cells)

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15 pages, 5404 KB

Open AccessArticle

The Effect of Home Bleaching Gel with Chitosan on Tooth Color and Mineral Alteration

by Görkem Kervancıoğlu and Derya Gürsel Sürmelioğlu

Gels 2025, 11(11), 933; https://doi.org/10.3390/gels11110933 - 20 Nov 2025

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Abstract

This study aimed to compare tooth mineralization and color changes achieved with two experimental bleaching gels containing chitosan and theobromine (16% CP or 6% HP, Group 1, 2) with the FGM Whiteness Perfect (16% CP) (Group 3) and BioWhitenProHome (6% HP) (Group 4). [...] Read more.

This study aimed to compare tooth mineralization and color changes achieved with two experimental bleaching gels containing chitosan and theobromine (16% CP or 6% HP, Group 1, 2) with the FGM Whiteness Perfect (16% CP) (Group 3) and BioWhitenProHome (6% HP) (Group 4). Ninety-six maxillary central teeth were divided into two groups for color and mineral evaluations. These groups were then further divided into four subgroups according to the bleaching agent (n = 12). Mineral analysis was performed with SEM-EDX before the bleaching, at the end of the treatment, and two weeks after treatment ended to assess changes. Color measurement was performed with a spectrophotometer before bleaching, on the 7th day of treatment, 24 h after final treatment, and two weeks after treatment ended. No significant difference among the groups was found in color change (p > 0.05), while mineralization differed significantly (p < 0.05). The ΔE₀₀₃ values of Group 4 and Group 2 were found to be close to each other. The highest calcium loss was detected in Group 3, whereas the most pronounced decrease in phosphorus values was observed in Group 4. Using theobromine and chitosan can provide clinicians with positive results for bleaching treatments, such as using lower HP concentrations and avoiding side effects. Full article

(This article belongs to the Special Issue Advances in Chitin- and Chitosan-Based Hydrogels (2nd Edition))

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29 pages, 1302 KB

Open AccessReview

Functional and Bioactive Performance of Premixed Bioceramic Sealers with Warm Obturation: A Scoping Review

by Patryk Wiśniewski, Stanisław Krokosz, Małgorzata Pietruska and Anna Zalewska

Gels 2025, 11(11), 932; https://doi.org/10.3390/gels11110932 - 20 Nov 2025

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Abstract

Premixed bioceramic sealers represent a recent advancement in endodontic obturation, combining bioactivity, moisture-induced mineralization and favorable handling properties. When used with warm gutta-percha techniques, these calcium silicate-based sealers are exposed to elevated temperatures that may influence their physicochemical behavior and interfacial performance. This [...] Read more.

Premixed bioceramic sealers represent a recent advancement in endodontic obturation, combining bioactivity, moisture-induced mineralization and favorable handling properties. When used with warm gutta-percha techniques, these calcium silicate-based sealers are exposed to elevated temperatures that may influence their physicochemical behavior and interfacial performance. This review aimed to summarize current evidence on premixed bioceramic sealers used in conjunction with thermoplastic obturation techniques. A comprehensive literature search was conducted in PubMed, Scopus, and Web of Science for studies published between January 2020 and July 2025 evaluating the physicochemical properties, bioactivity, sealing ability, fracture resistance, clinical outcomes and retreatability of premixed bioceramic sealers under warm obturation conditions. No meta-analysis was performed—this review provides a narrative synthesis of the available evidence within this scope. Twenty-five studies met the inclusion criteria. In vitro and ex vivo data indicate that premixed bioceramic sealers generally maintain chemical stability and bioactivity when exposed to clinically relevant heating protocols, with favorable dentinal tubule penetration, interfacial adaptation and the formation of calcium silicate hydrate, and hydroxyapatite at the sealer–dentin interface. These characteristics are associated with improved filling homogeneity, potential reinforcement of root dentin and high rates of periapical healing reported in limited short-term clinical studies. However, the evidence also highlights important challenges, including technique-sensitive retreatability, material remnants after re-instrumentation and concerns regarding overextension, and long-term dimensional stability. Within the limitations of predominantly in vitro and short-term clinical evidence, premixed bioceramic sealers used with warm gutta-percha techniques appear to be promising functional materials that combine mechanical sealing with bioactive and mineralizing potential. Standardized protocols and robust long-term clinical studies are needed to confirm their durability, retreatability and prognostic impact in routine endodontic practice. Full article

(This article belongs to the Special Issue Functional Gels for Dental Applications)

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22 pages, 4690 KB

Open AccessArticle

Copper Sulfide Nanoparticles Anchored in Cotton Linter Carbon Aerogel Promote the Adsorption/Photocatalytic Degradation of Organic Pollutants

by Yueyuan Xu, Yuxuan Guo, Canming Hu, Yueqi Zhou and Chengli Ding

Gels 2025, 11(11), 931; https://doi.org/10.3390/gels11110931 - 20 Nov 2025

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Abstract

The development of cheap and efficient photocatalysts for the degradation of organic pollutants in textile printing and dyeing wastewater is of great importance for addressing environmental issues, although it remains challenging. In this study, nano-CuS particles were doped on cotton linter aerogels using [...] Read more.

The development of cheap and efficient photocatalysts for the degradation of organic pollutants in textile printing and dyeing wastewater is of great importance for addressing environmental issues, although it remains challenging. In this study, nano-CuS particles were doped on cotton linter aerogels using a straightforward method for the degradation of methylene blue (MB) and organic pollutants in textile wastewater. Material morphology and structure were analyzed using XRD, SEM/EDS mapping, XPS, BET surface area measurements, and UV-Vis spectroscopy, while their performance was evaluated through various tests. The results demonstrated that a 10 mg catalyst material achieved complete degradation of a 20 mL methylene blue solution (15 mg/L) within 120 min. Moreover, the degradation rates of two types of textile wastewater, reactive red wastewater and reactive yellow wastewater, were both above 90% within 120 min and reached complete degradation within 150 min using the 10 mg catalyst material. The experimental results demonstrate that copper sulfide nanoparticles anchored in cotton linter carbon aerogel can increase the contact area of the photocatalytic reaction system, improve the photoelectron transfer, and thus enhance the photocatalytic reaction efficiency, providing a useful foundation for developing economical photocatalysts and effective dye degradation technologies. Full article

(This article belongs to the Section Gel Chemistry and Physics)

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17 pages, 21274 KB

Open AccessArticle

In Situ Steam-Assisted Synthesis of CTAB-Modified Geopolymer-Based Hectorite for Enhanced Adsorption of Congo Red

by Derui Chen, Chao Sun, Keying Sun, Mingyu Yan, Yang Yang, Hang Jin, Junda Guo, Jingna Jia, Longbin Xu and Xinyu Li

Gels 2025, 11(11), 930; https://doi.org/10.3390/gels11110930 - 19 Nov 2025

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Abstract

For deep purification of wastewater containing anionic dyes. In this study, cetyltrimethylammonium bromide (CTAB)-modified geopolymer-based hectorite was synthesized via a steam-assisted method using depolymerized illite-based geopolymer as the silicon source and CTAB as the modifier, enhancing its adsorption performance for anionic dyes. The [...] Read more.

For deep purification of wastewater containing anionic dyes. In this study, cetyltrimethylammonium bromide (CTAB)-modified geopolymer-based hectorite was synthesized via a steam-assisted method using depolymerized illite-based geopolymer as the silicon source and CTAB as the modifier, enhancing its adsorption performance for anionic dyes. The product was characterized by methods such as X-ray diffraction, and the effects of parameters such as adsorbent dosage and pH on the adsorption process were investigated. Adsorption experiments revealed that when the CTAB addition was 20%, the adsorption performance for Congo red was optimal (99.79%, 997.92 mg·g⁻¹), far superior to that of hectorite without CTAB (66.64%, 666.40 mg·g⁻¹). The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm model. Further comparison of changes before and after adsorption indicated that the adsorption mechanism primarily involved the combined effects of electrostatic interaction and hydrophobic effects. Additionally, after five adsorption–desorption cycles, the material maintained over 92% removal efficiency. By using different geopolymers as silicon sources to prepare CTAB-modified geopolymer-based hectorite, the high universality of this synthesis strategy was confirmed. This study provides a universal, green, and sustainable route for preparing efficient anionic dye adsorption materials and expands the high-value utilization of clay resources. Full article

(This article belongs to the Special Issue Development and Applications of Advanced Geopolymer Gel Materials)

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19 pages, 5717 KB

Open AccessArticle

Thermally Insulating Polyimide Aerogel Skeletons Constructed by Hybridizing the Al–O Network Phase

by Mingkang Wang, Shuai Yu, Jing Wang, Xin Zhao, Changpeng Yang, Ran Wei, Chun Liu and Sizhao Zhang

Gels 2025, 11(11), 929; https://doi.org/10.3390/gels11110929 - 19 Nov 2025

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Abstract

Polyimide aerogels have garnered considerable attention due to their high-performance combination of a lightweight nature, low thermal conductivity, and high mechanical strength, which renders them ideal candidates for thermal insulators in aerospace. However, the inherent conflict in achieving multifunctional (dimensional stability and mechanical [...] Read more.

Polyimide aerogels have garnered considerable attention due to their high-performance combination of a lightweight nature, low thermal conductivity, and high mechanical strength, which renders them ideal candidates for thermal insulators in aerospace. However, the inherent conflict in achieving multifunctional (dimensional stability and mechanical stiffness at high temperatures, and highly efficient thermal insulation) integration presents a great challenge. Here, we present an aerogel skeleton construction strategy based on hybridizing an Al–O network phase to create multifunctional polyimide aerogels. The resulting aerogels partially constructed by Al–O network phase exhibit an outstanding resistance to high temperatures (shrinkage of 0.56% after experiencing 200 °C for 2400 s), which is markedly superior to that of conventional polyimide aerogels. The excellent insulation capability of the aerogel is reflected in its low thermal conductivity (0.0214 W m⁻¹ K⁻¹) and its ability to maintain a cold-side temperature of just 59.7 °C under a 150 °C heat source. Furthermore, remarkable enhancements in mechanical properties are found at high-temperature conditions, providing evidence for the compressive stresses of 0.329 and 0.394 MPa under 3% strain at the respective temperatures of 200 and 250 °C, showing a clear trend of enhanced compressive stress with rising temperature. These advancements in high-temperature stability and mechanical properties substantially broaden the scope for their potential applications in aerospace thermal protection systems. Full article

(This article belongs to the Special Issue Preparation and Characteristics of Aerogel-Based Materials (2nd Edition))

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15 pages, 2097 KB

Open AccessArticle

Response Surface Methodology Optimization of Electron-Beam-Irradiated Carboxymethyl Cellulose/Citric Acid-Based Hydrogels

by Sa Rang Choi and Jung Myoung Lee

Gels 2025, 11(11), 928; https://doi.org/10.3390/gels11110928 - 19 Nov 2025

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Abstract

Electron beam irradiation (EBI) is an environmentally friendly cross-linking technique that can form covalent bonds between natural polymers without the use of chemical cross-linkers. In this study, carboxymethyl cellulose (CMC; 3000 cPs) and citric acid (CA) were used to prepare hydrogels under low-dose [...] Read more.

Electron beam irradiation (EBI) is an environmentally friendly cross-linking technique that can form covalent bonds between natural polymers without the use of chemical cross-linkers. In this study, carboxymethyl cellulose (CMC; 3000 cPs) and citric acid (CA) were used to prepare hydrogels under low-dose EBI conditions (7 kGy). The effects of composition variables were statistically analyzed using response surface methodology based on central composite design. The concentrations of CMC (4–14 wt%) and CA (1–4 wt%) were selected as independent variables, while the gel fraction, water absorption, and elastic modulus were employed as responses. Analysis of variance confirmed that the quadratic models were statistically significant (p < 0.05) with a high predictive reliability (R² = 0.91–0.98). Statistical validation demonstrated that the residuals were normally distributed and that all data fell within the 95% prediction interval, verifying the robustness of the model. Multi-response optimization identified an optimal composition of 8.88 wt% CMC and 0.03 wt% CA, yielding a predicted gel fraction of 88.7%, water absorption of 256 g/g, and modulus of 2273 Pa. The extended condition (CMC 9.12 wt%, CA 2.17 × 10⁻⁷ wt%) achieved similar absorbency with a ~9% higher modulus. This study established a reliable predictive model correlating the composition and properties of EBI-induced CMC–CA hydrogels, providing a foundation for optimizing eco-friendly hydrogel processes and scaling them up in the future. Full article

(This article belongs to the Special Issue Advanced Synthesis, Functionalization, and Applications of Biomass Hydrogels)

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19 pages, 6604 KB

Open AccessArticle

Adsorption Characteristics of Sodium Ions by Bentonite–Humic Acid Hydrogel: A Promising Water-Retaining Agent for Saline–Alkali Soil Improvement

by Weiye Liu, Mingjie Sun, Binghua Liu, Lin Peng, Xinghong Liu, Yanping Wang, Fangchun Liu and Hailin Ma

Gels 2025, 11(11), 927; https://doi.org/10.3390/gels11110927 - 19 Nov 2025

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Abstract

Sodium ions are the main harmful ions in coastal saline–alkali soils, and they seriously affect crop growth and soil structure. A bentonite/humic acid composite hydrogel, synthesized via graft copolymerization as a new type of water-retaining agent, can adsorb excessive Na⁺ in soil, [...] Read more.

Sodium ions are the main harmful ions in coastal saline–alkali soils, and they seriously affect crop growth and soil structure. A bentonite/humic acid composite hydrogel, synthesized via graft copolymerization as a new type of water-retaining agent, can adsorb excessive Na⁺ in soil, thereby slowing down its adverse effects. This study used batch adsorption experiments to systematically investigate the effects of contact time, initial concentration, pH, temperature, and repeated cyclic adsorption on Na⁺ adsorption performance of the hydrogel material. The results indicated that Na⁺ equilibrium was achieved in 25 min, and the maximum adsorption capacity was 91.29 mg/g. Optimal adsorption occurred at pH 6–8.5, particularly in neutral to weakly alkaline conditions. At 30–50 °C, the bentonite substrate maintained excellent adsorption performance despite structural damage to the grafted copolymer. Mechanistic analysis revealed that adsorption followed pseudo-second-order kinetics and the Langmuir isotherm model, indicating chemisorption-dominated monolayer adsorption controlled by both intra-particle and liquid film diffusion. These findings demonstrate the potential of bentonite-based hydrogels for remediating coastal saline–alkali soils by mitigating Na⁺ toxicity. Full article

(This article belongs to the Special Issue Preparation and Application of New Gel Adsorption Materials)

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19 pages, 1877 KB

Open AccessArticle

Cellulose Nanofibrils vs Nanocrystals: Rheology of Suspensions and Hydrogels

by Alexander S. Ospennikov, Alexander L. Kwiatkowski and Olga E. Philippova

Gels 2025, 11(11), 926; https://doi.org/10.3390/gels11110926 - 19 Nov 2025

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Abstract

Plant-derived nanocellulose particles, such as cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs), are becoming increasingly popular for a wide range of applications. In particular, when they are employed as rheology modifiers and/or fillers, a choice between CNFs and CNCs is often not obvious. [...] Read more.

Plant-derived nanocellulose particles, such as cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs), are becoming increasingly popular for a wide range of applications. In particular, when they are employed as rheology modifiers and/or fillers, a choice between CNFs and CNCs is often not obvious. Here, we present the results of a comparative study on the rheological properties of suspensions and gels of carboxymethylated CNFs and CNCs with the same surface chemistry, surface density of charged groups, and thickness. We demonstrate that, at the same weight concentration, CNF suspensions have much higher viscosity and storage modulus, which is due to their longer length providing many entanglements. However, when comparing at the same nanoparticle concentration relative to C*, the situation is reversed: viscosity and storage modulus of CNCs appear to be much higher. This may be due in particular to the higher rigidity and intrinsic strength of highly crystalline CNCs. The gel points for CNF and CNC suspensions (without crosslinker) were compared for the first time. It was found that in the case of CNFs, the gel point occurs at a 3.5-fold lower concentration compared to that of CNCs. Hydrogels were also obtained by crosslinking negatively charged nanocellulose particles of both types by divalent calcium cations. For the first time, the thermodynamic parameters of the crosslinking of carboxymethylated CNFs by calcium ions were determined. Isothermal titration calorimetry data revealed that, for both CNFs and CNCs, crosslinking is endothermic and driven by increasing entropy, which is most likely due to the release of water molecules surrounding the interacting nanoparticles and Ca²⁺ ions. The addition of CaCl₂ to suspensions of nanocellulose particles leads to an increase in the storage modulus; the increase being much more significant for CNCs. Physically crosslinked hydrogels of both CNFs and CNCs can be reversibly destroyed by increasing the shear rate and then quickly recover up to 85% of their original viscosity when the shear rate decreases. The recovery time for CFC networks is only 6 s, which is much shorter than that of CNC networks. This property is promising for various applications, where nanocellulose suspensions are subjected to high shear forces (e.g., mixing, stirring, extrusion, injection, coating) and then need to regain their original properties when at rest. Full article

(This article belongs to the Special Issue Advances in Cellulose-Based Hydrogels (4th Edition))

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22 pages, 1892 KB

Open AccessReview

Gel Delivery Systems in Dental Medicine: From Controlled Release to Regenerative Applications

by Dragos Ioan Virvescu, Ionut Luchian, Oana Cioanca, Gabriel Rotundu, Florinel Cosmin Bida, Dana Gabriela Budala, Mihaela Scurtu, Zinovia Surlari, Oana-Maria Butnaru and Monica Hancianu

Gels 2025, 11(11), 925; https://doi.org/10.3390/gels11110925 - 19 Nov 2025

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Abstract

Gel-based delivery systems have emerged as versatile platforms in dentistry due to their biocompatibility, injectability, tunable rheology, and ability to localize therapeutic agents at the site of application. This review synthesizes current evidence on hydrogels, thermosensitive gels, mucoadhesive gels, nanoparticle-loaded gels, and stimuli-responsive [...] Read more.

Gel-based delivery systems have emerged as versatile platforms in dentistry due to their biocompatibility, injectability, tunable rheology, and ability to localize therapeutic agents at the site of application. This review synthesizes current evidence on hydrogels, thermosensitive gels, mucoadhesive gels, nanoparticle-loaded gels, and stimuli-responsive systems, highlighting their structural characteristics, mechanisms of drug release, and clinical relevance. Mucoadhesive formulations demonstrate prolonged retention in periodontal pockets and oral mucosa, improving the efficacy of antimicrobials and anti-inflammatory agents. Thermosensitive gels enable minimally invasive administration and in situ gelation, supporting controlled release at body temperature. Nanoparticle-loaded gels exhibit enhanced drug stability and deeper tissue penetration, while “smart” gels respond to environmental stimuli such as pH or temperature to modulate release profiles. Clinical findings indicate reductions in probing depth, improved wound healing, decreased bacterial load, and better patient comfort when gel systems are used as adjuncts to mechanical therapy or regenerative procedures. However, despite these advances, challenges such as variability in gel stability, manufacturing reproducibility, regulatory approval pathways, and limited long-term clinical evidence still constrain widespread adoption of these systems in routine practice. Full article

(This article belongs to the Special Issue Gels for Oral, Maxillofacial, Dental Medicine or Cosmetic Use)

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44 pages, 3588 KB

Open AccessReview

Hydrogels for Climate Change Mitigation: Applications in Water Harvesting, Passive Cooling, and Environmental Solutions

by Julia Gałęziewska, Weronika Kruczkowska, Katarzyna Helena Grabowska, Żaneta Kałuzińska-Kołat and Elżbieta Płuciennik

Gels 2025, 11(11), 924; https://doi.org/10.3390/gels11110924 - 19 Nov 2025

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Abstract

Climate change presents significant global challenges, with rising temperatures, extreme weather events, and degrading ecosystems threatening both human societies and the environment. The increasing intensity of these climatic effects demands innovative approaches to adaptation and mitigation. Hydrogels, three-dimensional networks of crosslinked polymers with [...] Read more.

Climate change presents significant global challenges, with rising temperatures, extreme weather events, and degrading ecosystems threatening both human societies and the environment. The increasing intensity of these climatic effects demands innovative approaches to adaptation and mitigation. Hydrogels, three-dimensional networks of crosslinked polymers with water absorption and retention properties, have become viable multipurpose materials for climate solutions in response to these pressing issues. This review examines four primary applications of hydrogels as climate technologies: atmospheric water harvesting, passive cooling, soil health enhancement, and energy conservation. These materials address climate challenges through their unique properties including high water absorption capacity, stimuli-responsive behavior, and biocompatibility. By effectively capturing moisture, hydrogel-based devices provide sustainable freshwater production in areas with limited water resources. For thermal management, they offer passive cooling through evaporative processes, reducing energy consumption compared to conventional air conditioning systems. Superabsorbent hydrogels in agriculture help drought-resistant crop development in arid areas and improve soil water retention. Smart windows with thermochromic hydrogels allow for passive energy savings by dynamically modulating the sun’s light without the need for additional electricity. Through integrated deployment techniques, biodegradable formulations from sustainable sources handle various climate issues while ensuring environmental compatibility. Full article

(This article belongs to the Special Issue Gels for Adsorption and Separation)

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28 pages, 7487 KB

Open AccessReview

Aerogel-Based Phase Change Materials Meet Flame Retardancy: From Materials to Properties

by Panpan Zhao, Shudi Ying, Riming Hu, Jiachen Ma and Xuchuan Jiang

Gels 2025, 11(11), 923; https://doi.org/10.3390/gels11110923 - 19 Nov 2025

Viewed by 626

Abstract

Energy storage materials play a crucial role in enhancing system efficiency by bridging the mismatch between energy supply and demand. Among them, organic phase change materials (PCMs) are particularly attractive due to their high energy storage density, no phase segregation and ability to [...] Read more.

Energy storage materials play a crucial role in enhancing system efficiency by bridging the mismatch between energy supply and demand. Among them, organic phase change materials (PCMs) are particularly attractive due to their high energy storage density, no phase segregation and ability to maintain nearly constant temperatures during phase transitions. However, their practical application is hindered by drawbacks such as leakage and flammability. Aerogels, characterized by high porosity, low density, and tunable structures, provide effective support matrices for encapsulating PCMs, thereby improving shape stability and enabling fire safety improvements when combined with flame-retardant strategies. Despite significant progress in PCM and aerogel research over the past decade, comprehensive studies dedicated to flame-retardant aerogel-based PCMs remain limited. This review systematically summarizes current flame-retardant approaches for aerogel-based PCMs, highlights recent advances in aerogel-supported systems, and outlines the key challenges and future opportunities for developing next-generation energy storage composites with improved thermal reliability, safety, and sustainability. Full article

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

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25 pages, 4730 KB

Open AccessArticle

β-Cyclodextrin Inclusion Complexes of Curcumin and Synthetic Analogues in PVA/Carrageenan Hydrogels: A Platform for Sustained Release and Microbial Control

by Patricia Daiane Zank, Matheus da Silva Gularte, André Ricardo Fajardo, Matheus Pereira de Albuquerque, Vithor Parada Garcia, Rafaely Piccioni Rosado, Letícia Zibetti, Clarissa Piccinin Frizzo, Bruno Nunes da Rosa, Cláudio Martin Pereira de Pereira, Janice Luehring Giongo and Rodrigo de Almeida Vaucher

Gels 2025, 11(11), 922; https://doi.org/10.3390/gels11110922 - 18 Nov 2025

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Abstract

This study describes the development of β-cyclodextrin (β-CD) inclusion complexes of curcumin (CUR) and a synthetic curcuminoid analogue (CN56), which were incorporated into poly(vinyl alcohol)/κ-carrageenan hydrogel films to create a multifunctional system capable of sustained drug release and effective antimicrobial action. Carrageenan was [...] Read more.

This study describes the development of β-cyclodextrin (β-CD) inclusion complexes of curcumin (CUR) and a synthetic curcuminoid analogue (CN56), which were incorporated into poly(vinyl alcohol)/κ-carrageenan hydrogel films to create a multifunctional system capable of sustained drug release and effective antimicrobial action. Carrageenan was extracted from Gigartina skottsbergii, and hydrogels were prepared using a freeze–thaw crosslinking method. The inclusion complexes were formed at a 1:6 molar ratio, achieving loading efficiencies of 75.62% for CUR and 79.00% for CN56. FTIR confirmed molecular interactions between the complexes and the polymeric matrix, accompanied by reduced crystallinity and increased amorphous character. Thermogravimetric analysis revealed enhanced thermal stability, with degradation onset temperatures above 239 °C, while DSC analysis indicated irreversible amorphization after the first heating cycle. SEM analysis showed improved surface uniformity in complex-loaded films compared with those containing free compounds. Swelling experiments demonstrated significantly greater fluid uptake in complex-loaded hydrogels, particularly for CN56 (1080% after 45 min). Controlled release studies revealed sustained drug release profiles, with 76.49% of CUR and 56.02% of CN56 released over 36 h, following Fickian diffusion mechanisms. In vitro antimicrobial assays confirmed marked activity of CUR and CN56 against Gardnerella vaginalis, a key pathogen associated with bacterial vaginosis. Biocompatibility tests, including hemolysis and MTT reduction assays, indicated low cytotoxicity and satisfactory hemocompatibility. Rheological analysis further demonstrated increased viscosity and potential mucoadhesive behavior. Collectively, these findings highlight the potential of carrageenan-based PVA hydrogels as innovative pharmaceutical platforms for the prevention and treatment of recurrent bacterial vaginosis, offering a promising alternative to conventional therapies. Full article

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

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25 pages, 8587 KB

Open AccessArticle

Alginate–Aluminosilicate Clay Beads for Sustained Release of Chlortetracycline Hydrochloride: Development and In Vitro Studies

by Aicha Nour Laouameria, Meriem Fizir, Sami Touil, Amina Richa, Nassima Benamara, Houda Douba, Liu Wei, Djamila Aouameur, Houria Rezala, Attila Csík and Tamás Fodor

Gels 2025, 11(11), 921; https://doi.org/10.3390/gels11110921 - 18 Nov 2025

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Abstract

This study reports the preparation of alginate (Alg) beads incorporating different amounts of halloysite nanotubes (HNTs) and kaolin (K) in the presence of Ca²⁺ ions to compare their drug loading and release behaviors. The resulting composites, HNTs@Alg and K@Alg, were characterized using [...] Read more.

This study reports the preparation of alginate (Alg) beads incorporating different amounts of halloysite nanotubes (HNTs) and kaolin (K) in the presence of Ca²⁺ ions to compare their drug loading and release behaviors. The resulting composites, HNTs@Alg and K@Alg, were characterized using FTIR, SEM–EDS, XRD, and XPS analyses. Chlortetracycline hydrochloride (CTC) was employed as a model antibiotic to evaluate their drug delivery performance. The concentration of Alg and the incorporation of HNTs or K markedly influenced the adsorption capacity and release profile. The maximum drug loading capacities were 48.12 ± 1.4 mg/g for HNTs, 40.1 ± 1.2 mg/g for K, 59.85 ± 2.3 mg/g for HNTs@Alg-1 (1 g HNTs and 1% Alg), and 68.74 ± 2.1 mg/g for K@Alg-1 (1 g K and 1% Alg). The inclusion of Alg enhanced sustained release, extending beyond 100 h. Among the composite beads, HNTs@Alg-1 showed superior CTC release behavior compared to K@Alg-1. Furthermore, antibacterial assays confirmed that the CTC-loaded beads effectively inhibited E. coli and S. aureus, demonstrating maintained drug activity after encapsulation. Both systems effectively prolonged CTC release and exhibited antibacterial efficacy, highlighting their potential as controlled drug delivery matrices for wound treatment applications. Full article

(This article belongs to the Special Issue Designing Gels for Wound Healing and Drug Delivery Systems)

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20 pages, 3050 KB

Open AccessArticle

In Vitro Evaluation of a Gelatin Type A/PVA Hydrogel Functionalized with Roasted Green Tea (Camellia sinensis)

by Maria Clarisa Salazar-Nava, Rene Garcia-Contreras, Benjamin Aranda-Herrera, Gabriela Hernandez-Gomez, Carlos A. Jurado, Abdulrahman Alshabib and Patricia Alejandra Chavez-Granados

Gels 2025, 11(11), 920; https://doi.org/10.3390/gels11110920 - 18 Nov 2025

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Abstract

Hydrogels are versatile biomaterials for controlled drug delivery and tissue regeneration due to their biocompatibility and tunable degradation. Hydrogel was synthesized with a gelatin type A/polyvinyl alcohol functionalized with aqueous extract of roasted green tea (10% w/v) and evaluated its [...] Read more.

Hydrogels are versatile biomaterials for controlled drug delivery and tissue regeneration due to their biocompatibility and tunable degradation. Hydrogel was synthesized with a gelatin type A/polyvinyl alcohol functionalized with aqueous extract of roasted green tea (10% w/v) and evaluated its physiobiological performance in vitro. Degradation was assessed under enzymatic (collagenase II, trypsin) and hydrolytic conditions; swelling was performed with distilled water, cytocompatibility was tested on human periodontal ligament stem cells by MTT; antibacterial activity was measured against Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The hydrogel showed complete hydrolytic degradation within 60 min and enzymatic degradation within 70 min, the hydrogel increased its mass by approximately 6.3 times relative weight, reached its maximum swelling in the range of 478–537%, (19% for the experimental group), while maintaining PDLSC viability (>80%). It exhibited significant antibacterial activity (inhibition: S. aureus 78.6%, S. mutans 67.4%, E. coli 73.2%). Importantly, in osteogenic medium, the hydrogel enhanced osteogenic differentiation of PDLSCs, evidenced by increased calcium deposition and positive Alizarin Red staining versus controls. These data position the gelatin/PVA/roasted green tea hydrogel as a bioactive, resorbable candidate for dental applications—particularly as an antimicrobial dressing and adjunct for periodontal bone regeneration material. Full article

(This article belongs to the Special Issue Hydrogels for Bone Regeneration (2nd Edition))

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17 pages, 4174 KB

Open AccessArticle

Synthesis and Evaluation of Carbon Black-Containing Hydrogels for the Adsorption of 5-Fluorouracil

by Ritsuko Sekiguchi-Arai, Yoshiko Yamazaki, Takao Sato, Naoki Noma, Kengo Oka and Mitsunobu Iwasaki

Gels 2025, 11(11), 919; https://doi.org/10.3390/gels11110919 - 18 Nov 2025

Viewed by 337

Abstract

The widely used anticancer drug 5-Fluorouracil (5-FU) may potentially elicit adverse side effects on the eyes. To address this problem, we aimed to synthesize hydrogels containing carbon black (CB), a porous material, for use as a 5-FU-adsorbent contact lens material. High-performance liquid chromatography [...] Read more.

The widely used anticancer drug 5-Fluorouracil (5-FU) may potentially elicit adverse side effects on the eyes. To address this problem, we aimed to synthesize hydrogels containing carbon black (CB), a porous material, for use as a 5-FU-adsorbent contact lens material. High-performance liquid chromatography revealed a direct correlation between the specific surface area of CB particles and 5-FU adsorption. CB particles with functional surface groups were characterized by superior dispersibility in monomer solutions, whereas the results of combustion ion chromatography indicated that 5-FU adsorption was higher for hydrogels with a higher water content and that the addition of CB to the hydrogel further enhanced the rate of 5-FU adsorption by 21%. In addition, 5-FU was strongly fixed within the CB-printed hydrogel matrix even after washing, with hydrophobic interactions with CB being established to be highly effective for binding 5-FU. Collectively, the findings of our study revealed that CB-printed hydrogel is a promising novel material for fabricating 5-FU-trapping contact lenses. Full article

(This article belongs to the Section Gel Applications)

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69 pages, 9787 KB

Open AccessReview

Hydrogel Films in Biomedical Applications: Fabrication, Properties and Therapeutic Potential

by Sabuj Chandra Sutradhar, Hyoseop Shin, Whangi Kim and Hohyoun Jang

Gels 2025, 11(11), 918; https://doi.org/10.3390/gels11110918 - 17 Nov 2025

Viewed by 811

Abstract

Hydrogel films have emerged as versatile platforms in biomedical engineering due to their unique physicochemical properties, biocompatibility, and adaptability to diverse therapeutic needs. This review provides a comprehensive overview of hydrogel film materials, including natural biopolymers, synthetic polymers, and multifunctional composites, highlighting their [...] Read more.

Hydrogel films have emerged as versatile platforms in biomedical engineering due to their unique physicochemical properties, biocompatibility, and adaptability to diverse therapeutic needs. This review provides a comprehensive overview of hydrogel film materials, including natural biopolymers, synthetic polymers, and multifunctional composites, highlighting their structural and functional diversity. We examine key fabrication techniques—ranging from solvent casting and photopolymerization to advanced methods like microfluidics and 3D printing—and discuss how these influence film architecture and performance. The biomedical applications of hydrogel films span wound healing, drug delivery, tissue engineering, ophthalmology, and implantable biosensors, with recent innovations enabling stimuli-responsive behavior, multi-drug loading, and integration with wearable electronics. Despite their promise, hydrogel films face persistent challenges in mechanical durability, sterilization, storage stability, regulatory approval, and scalable manufacturing. We conclude by identifying critical research gaps and outlining future directions, including AI-guided design, sustainable material development, and the establishment of standardized, regulatory-aligned, and industrially scalable fabrication strategies to accelerate clinical translation. Full article

(This article belongs to the Special Issue Gel Film and Its Wide Range of Applications)

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37 pages, 2120 KB

Open AccessReview

Liposomal Nanosystems Versus Hydrogels in the Prevention and Treatment of Metabolic Diseases

by Mihaela-Carmen Eremia, Ramona-Daniela Pavaloiu, Fawzia Sha’at, Dana Maria Miu, Gabriela Savoiu and Anca Daniela Raiciu

Gels 2025, 11(11), 917; https://doi.org/10.3390/gels11110917 - 16 Nov 2025

Viewed by 489

Abstract

Liposomal nano-systems and hydrogels are two types of nano-technological systems that have promising applications in the prevention and treatment of metabolic diseases (diabetes, obesity, dyslipidemias, and metabolic syndrome), which are a major public health concern worldwide. Advances in nanotechnology and biomaterials have enabled [...] Read more.

Liposomal nano-systems and hydrogels are two types of nano-technological systems that have promising applications in the prevention and treatment of metabolic diseases (diabetes, obesity, dyslipidemias, and metabolic syndrome), which are a major public health concern worldwide. Advances in nanotechnology and biomaterials have enabled the development of new platforms for the controlled delivery of nutrients or bioactive compounds in order to solve these issues. This review compares the characteristics, advantages, and limitations of these two systems, with a focus on their applicability in the prevention and treatment of metabolic diseases. Full article

(This article belongs to the Special Issue Recent Research on Medical Hydrogels (2nd Edition))

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20 pages, 5809 KB

Open AccessArticle

Impact of Glutenin/Gliadin Ratio and Maltodextrin on Structural and Functional Properties of Soy Protein Isolate–Wheat Gluten Protein Composite Gel

by Min Qu, Chang Ge, Sitong Li, Ying Zhu, Peixiu Jiang, Yuyang Huang, Bingyu Sun, Linlin Liu and Xiuqing Zhu

Gels 2025, 11(11), 916; https://doi.org/10.3390/gels11110916 - 16 Nov 2025

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Abstract

Enhancing the gel properties of soy protein isolate (SPI) is crucial for forming stable gel systems through interactions with other plant proteins and polysaccharides. This study investigated the contribution of different ratios of glutenin (Glu)/gliadin (Gli) and maltodextrin (MD) to SPI–wheat gluten protein [...] Read more.

Enhancing the gel properties of soy protein isolate (SPI) is crucial for forming stable gel systems through interactions with other plant proteins and polysaccharides. This study investigated the contribution of different ratios of glutenin (Glu)/gliadin (Gli) and maltodextrin (MD) to SPI–wheat gluten protein (WGP) composite gels. SPI-WGP composite gels were prepared by varying the Glu/Gli ratio (0:10, 3:7, 4:6, 5:5, 6:4, 7:3, and 10:0) and adjusting the MD addition level (0, 2, 4, and 6%). Subsequently, the textural properties, water-holding capacity (WHC), rheological behavior, secondary structure, intermolecular forces, and microstructure of the composite gels were characterized. Results indicated that adding 4% MD with a Glu/Gli ratio of 4:6, compared with the SPI control group gel, the WHC, gel strength, and β-sheet content of the composite gel increased by 37.9%, 164.5%, and 30.6%, respectively. Hydrophobic interactions and hydrogen bonds became dominant after MD incorporation. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM) confirmed that the two proteins interact with MD to form a supported, dense, and homogeneous gel system. Excess MD caused phase separation in the composite gel system, disrupting the gel structure. This study provides important references for the development and potential applications of SPI-WGP composite gels. Full article

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

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25 pages, 16835 KB

Open AccessArticle

Thermochemical Degradation of a Polyacrylamide Gel as a Dual-Function Strategy for Enhanced Oil Recovery and Reservoir Remediation

by Jiaying Wang, Renbao Zhao, Yuan Yuan, Yunpeng Zhang, Guangsen Zhu, Jingtong Tian, Haiyang Zhang, Haitao Ren, Guanghui Zhou and Bin Liao

Gels 2025, 11(11), 915; https://doi.org/10.3390/gels11110915 - 16 Nov 2025

Viewed by 245

Abstract

The accumulation of residual hydrolyzed polyacrylamide (HPAM) gel or molecular-based solutions in reservoirs after polymer flooding poses dual challenges: irreversible formation damage and long-term environmental risk issues. However, existing research mainly focuses on treating polymers in surface-produced water, neglecting both in situ decomposition [...] Read more.

The accumulation of residual hydrolyzed polyacrylamide (HPAM) gel or molecular-based solutions in reservoirs after polymer flooding poses dual challenges: irreversible formation damage and long-term environmental risk issues. However, existing research mainly focuses on treating polymers in surface-produced water, neglecting both in situ decomposition of residual polymer gel or molecular-based solutions in reservoirs and the degradation of HPAM gels under high temperatures from in situ combustion (ISC). This work investigates the thermochemical behavior of HPAM gel during ISC and its dual-function role in enhanced oil recovery (EOR) and reservoir remediation. It was demonstrated that the residual gel and/or molecular-based solutions undergo efficient degradation, serving as an in situ fuel that significantly reduces the activation energy for crude oil oxidation by up to 58.4% in the low-temperature stage and 75.2% in the high-temperature stage. Factors influencing the gel’s degradation and the combustion process, including its molecular weight, ionic type, and crude oil viscosity, were systematically evaluated. Optimal conditions achieved over 90% gel degradation. Combustion tube experiments validated the dual benefits of this approach: an incremental oil recovery of 68.6% and an average HPAM gel removal efficiency of 64.8%. This work presents a novel strategy for utilizing retained gels in situ to simultaneously enhance oil recovery and mitigate gel-induced formation damage, offering significant insights for the management of mature gel-treated reservoirs. Full article

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

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26 pages, 2347 KB

Open AccessReview

Hydrogels for Bone Regeneration: Properties, Additives, Preclinical and Clinical Applications

by Nesya Graupe, Saliha Ahmad, Ahmad Zia, Michael Hadjiargyrou and Azhar Ilyas

Gels 2025, 11(11), 914; https://doi.org/10.3390/gels11110914 - 16 Nov 2025

Viewed by 1005

Abstract

Severe bone loss from trauma, fractures, tumor resections, and disease are devastating injuries that do not heal completely without external, and most of the time surgical, interventions. Although surgical interventions such as bone grafts and metal prostheses are commonly employed, these conventional approaches [...] Read more.

Severe bone loss from trauma, fractures, tumor resections, and disease are devastating injuries that do not heal completely without external, and most of the time surgical, interventions. Although surgical interventions such as bone grafts and metal prostheses are commonly employed, these conventional approaches present several limitations, including limited donors, risks of immune rejection and postoperative inflammation, and significant pain experienced by both donors and recipients. Hydrogels offer a promising alternative because of their controllable mechanical properties, biocompatibility, and structural resemblance to the extracellular matrix. In addition, hydrogels can be modified with substances such as growth factors, hormones, and drugs to facilitate accelerated bone repair. This review summarizes the recent advances in hydrogel development for bone repair, their structural design, biological functionality, and preclinical and clinical applications. Full article

(This article belongs to the Special Issue Polymeric Hydrogels for Biomedical Application (2nd Edition))

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22 pages, 9430 KB

Open AccessArticle

Micropatterned Composite Hydrogel Sheet with Surface Electronic Conductive Network for Ultrasensitive Strain Sensing

by Ruidong Chu, Mingyu Liu, Wenxia Liu, Zhaoping Song, Guodong Li, Dehai Yu, Xiaona Liu and Huili Wang

Gels 2025, 11(11), 913; https://doi.org/10.3390/gels11110913 - 15 Nov 2025

Viewed by 267

Abstract

Conductive hydrogels show great promise for wearable sensors but suffer from low sensitivity in small strain ranges. In this study, we developed a micropatterned composite hydrogel sheet (thickness: 1.2 ± 0.1 mm) by constructing a continuous electronic conductive network of carbon nanotubes (CNTs) [...] Read more.

Conductive hydrogels show great promise for wearable sensors but suffer from low sensitivity in small strain ranges. In this study, we developed a micropatterned composite hydrogel sheet (thickness: 1.2 ± 0.1 mm) by constructing a continuous electronic conductive network of carbon nanotubes (CNTs) on a highly crosslinked micropatterned hydrogel sheet. The sheet was fabricated via a two-step synthesis of a polyvinyl alcohol/polyacrylic acid polymer network—crosslinked by Zr⁴⁺ in a glycerol-water system—using sandpaper as the template. The first step ensured tight conformity to the template, while the second step preserved the micropattern’s integrity and precision. The reverse sandpaper micropattern enables secure bonding of CNTs to the hydrogel and induces localized stress concentration during stretching. This triggers controllable cracking in the conductive network, allowing the sensor to maintain high sensitivity even in small strain ranges. Consequently, the sensor exhibits ultra-high sensitivity, with gauge factors of 76.1 (0–30% strain) and 203.5 (30–100% strain), alongside a comfortable user experience. It can detect diverse activities, from subtle physiological signals and joint bending to complex hand gestures and athletic postures. Additionally, the micropatterned composite hydrogel sheet also demonstrates self-healing ability, adhesiveness, and conformability, while performing effectively under extreme temperatures and sweaty conditions. This innovative structure and sensing mechanism—leveraging stress concentration and controlled crack formation—provides a strategy for designing wearable electronics with enhanced performance. Full article

(This article belongs to the Special Issue Advancements in Biopolymer-Based Functional Hydrogels for Intelligent Wearable Devices and Textiles)

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15 pages, 1515 KB

Open AccessArticle

Dual-Function Role of Phenolated Albumin in Hemin-Mediated Hydrogel Formation

by Shinji Sakai, Yuki Kitatani, Maasa Shiba, Thotage Asanka Vishwanath, Kelum Chamara Manoj Lakmal Elvitigala, Wildan Mubarok and Kousuke Moriyama

Gels 2025, 11(11), 912; https://doi.org/10.3390/gels11110912 - 15 Nov 2025

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Abstract

Enzymatically crosslinked hydrogels are important in biomedical applications. However, conventional horseradish peroxidase (HRP)-based systems are expensive, unstable, and potentially immunogenic. Herein, we introduce hemin/albumin complexes as cost-effective and biocompatible catalysts for phenol-mediated hydrogel formation. Phenolated bovine serum albumins (BSA-LPh, -MPh, and-HPh) with different [...] Read more.

Enzymatically crosslinked hydrogels are important in biomedical applications. However, conventional horseradish peroxidase (HRP)-based systems are expensive, unstable, and potentially immunogenic. Herein, we introduce hemin/albumin complexes as cost-effective and biocompatible catalysts for phenol-mediated hydrogel formation. Phenolated bovine serum albumins (BSA-LPh, -MPh, and-HPh) with different degrees of substitution were synthesized and complexed with hemin. Spectroscopic analysis demonstrated that phenol modification altered the hemin microenvironment, resulting in distinct shifts in the Soret band. Functional assays revealed that albumin complexation enhanced catalytic activity compared to hemin alone. Moderate phenol modification provided an optimal balance between catalytic efficiency and hydrogel integration, whereas excessive modification reduced the performance of the enzyme. Hydrogels containing hemin/BSA-Ph complexes exhibited controllable protein retention and high cytocompatibility (>90%) with mouse fibroblast 10T1/2 cells. These findings demonstrate that hemin/albumin complexes are promising, cost-effective, and cytocompatible alternatives to HRP systems for hydrogel-based biomedical and nonclinical applications. Full article

(This article belongs to the Special Issue Novel Functional Gels for Biomedical Applications (2nd Edition))

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13 pages, 3165 KB

Open AccessArticle

Calcined Xerogels of C/TiO₂ Nanostructures for Solar-Driven Photocatalytic Hydrogen Production

by Yong Li, Hongpeng Zhang, Canni Zhuo, Xixi Sun, Jiaqi Gao and Yali Zhao

Gels 2025, 11(11), 911; https://doi.org/10.3390/gels11110911 - 14 Nov 2025

Viewed by 317

Abstract

The solar-driven water splitting for the production of renewable green hydrogen fundamentally relies on the exploration of efficient photocatalysts. Nanostructured TiO₂ is widely recognized as a promising material for photocatalysis, yet it remains hindered by inadequate light harvesting and fast photogenerated carrier [...] Read more.

The solar-driven water splitting for the production of renewable green hydrogen fundamentally relies on the exploration of efficient photocatalysts. Nanostructured TiO₂ is widely recognized as a promising material for photocatalysis, yet it remains hindered by inadequate light harvesting and fast photogenerated carrier recombination. Herein, calcined C/TiO₂ xerogels with yolk–shell and core–shell nanostructures (denoted as YS-C/TiO₂ and CS-C/TiO₂) were designed and fabricated via a typical sol–gel–calcination assisted approach. Thanks to the encapsulation of carbon nanospheres into TiO₂, it effectively enhances light absorption, improves carrier separation, and lessens carrier recombination, making the well-designed YS-C/TiO₂ composite display a remarkable hydrogen evolution rate of 975 µmol g⁻¹ h⁻¹ under simulated solar light irradiation and without the use of any co-catalyst, which is approximately 21.7 times that of the commercial TiO₂. The work provides an efficacious design concept in developing nanostructured TiO₂-based photocatalysts and in boosting broad photocatalytic applications. Full article

(This article belongs to the Section Gel Chemistry and Physics)

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31 pages, 6033 KB

Open AccessArticle

Synergistic and Intelligent Hydrogel for Conducting Osteoblast Proliferation: Synthesis, Characterization, and Multifunctional Properties

by Karen Michelle Guillén-Carvajal, Benjamín Valdez-Salas, Ernesto Alonso Beltrán-Partida, Jorge Salomón Salvador-Carlos, Mario Alberto Curiel-Álvarez, Jhonathan Castillo-Saenz, Daniel González-Mendoza and Nelson Cheng

Gels 2025, 11(11), 910; https://doi.org/10.3390/gels11110910 - 14 Nov 2025

Viewed by 315

Abstract

Current trends in intelligent hydrogels design for tissue engineering demand multifunctional biomaterials that respond to external stimuli, while maintaining adhesion, controlled degradation, and cytocompatibility. The present work describes the synthesis and characterization of a novel, intelligent and synergistic hydrogel for promoting osteoblastic growth [...] Read more.

Current trends in intelligent hydrogels design for tissue engineering demand multifunctional biomaterials that respond to external stimuli, while maintaining adhesion, controlled degradation, and cytocompatibility. The present work describes the synthesis and characterization of a novel, intelligent and synergistic hydrogel for promoting osteoblastic growth and regeneration. The hydrogel comprises a complex matrix blend of natural biodegradable polymers, vitamins (A, K2, D3, and E), and bioactive components such as zinc phosphate nanoparticles and manganese-doped hydroxyapatite to improve osteoblastic functionality. The hydrogel proved to have physicochemical properties for recovery and self-healing, highlighting its potential application as an auxiliary in bone rehabilitation. Key parameters such as rheological behavior, moisture content, water absorption, solubility, swelling, biodegradability, and responsiveness to temperature and pH variations were thoroughly evaluated. Furthermore, its adhesion to different surfaces and biocompatibility were confirmed. Skin contact test revealed no inflammatory, allergic, or secondary effects, indicating its safety for medical applications. Importantly, the hydrogel showed high biocompatibility with no cytotoxicity signs, favoring cell migration and highlighting its potential for applications in regenerative medicine. Full article

(This article belongs to the Special Issue Innovative Approaches of Biopolymer-Based Hydrogels: Development, Characterization, and Biomedical Applications)

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23 pages, 11038 KB

Open AccessArticle

Phospholipid-Based Ultraflexible Nanovesicular Gel of Sertaconazole Nitrate for the Treatment of Skin Fungal Infections: Statistical Optimization, In Vitro and Preclinical Assessment

by Malleswara Rao Peram, Sachin R. Patil, Vidyadhara Suryadevara, Srinivasa Rao Yarguntla, Smita Kamalakar, Preeti Patil, Kamala Kumari Paravastu, Manohar Kugaji and Sameer Nadaf

Gels 2025, 11(11), 909; https://doi.org/10.3390/gels11110909 - 13 Nov 2025

Viewed by 355

Abstract

Sertaconazole nitrate (SN), a broad-spectrum antifungal agent, is clinically employed against diverse dermatophyte infections. Its therapeutic efficacy, however, is constrained by poor aqueous solubility (0.006 mg/mL) and insufficient skin penetration from current commercial formulations. To address these limitations, this research focused on developing, [...] Read more.

Sertaconazole nitrate (SN), a broad-spectrum antifungal agent, is clinically employed against diverse dermatophyte infections. Its therapeutic efficacy, however, is constrained by poor aqueous solubility (0.006 mg/mL) and insufficient skin penetration from current commercial formulations. To address these limitations, this research focused on developing, optimizing (using a 3² factorial design), and assessing a topical nanovesicular gel incorporating sertaconazole nitrate-loaded ultraflexible liposomes (SN-UFLs) to enhance antifungal performance. The vesicles exhibited near-spherical morphology, with sizes ranging from 104.40 ± 1.20 to 151.90 ± 2.14 nm, zeta potential (ZP) values between −21.50 ± 1.25 and −51.20 ± 2.25 mV, and entrapment efficiency (EE) values from 77.60 ± 2.50% to 86.04 ± 3.20%. The optimized SN-UFL formulation (OPT-SN-UFL) was then integrated into a carbopol gel base. This SN-UFL-Gel was characterized for pH (6.5 ± 0.20), viscosity (499.66 ± 15 cP), spreadability (205 ± 1.50%), extrudability (154.18 ± 2.48 g/cm²), and drug content (96.7 ± 2.50%), as well as ex vivo skin permeation, skin irritation potential, and in vitro and in vivo antifungal efficacy. Compared with the marketed formulation, higher drug permeation and skin deposition were observed for SN-UFL-Gel. The SN-UFL-Gel exhibited a larger zone of inhibition (25 ± 1.50 mm) against Candida albicans compared to the commercially available formulation (20 ± 1.72 mm). The in vivo animal studies showed that SN-UFL-Gel showed better antifungal activity by efficient inhibition of infection induced in rats with Trichophyton mentagrophytes. The SN-UFL-Gel showed no signs of skin irritation and was stable at 4 ± 1, 25 ± 2, and 40 ± 2 °C for 3 months. Conclusively, the current work divulged successful augmentation of the overall effectiveness of sertaconazole nitrate by using deformable liposomes as a promising nanocarrier. Full article

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33 pages, 5540 KB

Open AccessReview

Silk Fibroin-Derived Smart Living Hydrogels for Regenerative Medicine and Organoid Engineering: Bioactive, Adaptive, and Clinically Translatable Platforms

by Asim Mushtaq, Khai Ly Do, Abdul Wahab, Muhammad Yousaf, Abdul Rahman, Hamid Hussain, Muhammad Ali, Pingfan Du and Miao Su

Gels 2025, 11(11), 908; https://doi.org/10.3390/gels11110908 - 13 Nov 2025

Viewed by 738

Abstract

Silk fibroin (SF) has evolved from a traditional biopolymer to a leading regenerative medicine material. Its combination of mechanical strength, biocompatibility, tunable degradation, and molecular adaptability makes SF a unique matrix that is both bioactive and intelligent. Advances in hydrogel engineering have transformed [...] Read more.

Silk fibroin (SF) has evolved from a traditional biopolymer to a leading regenerative medicine material. Its combination of mechanical strength, biocompatibility, tunable degradation, and molecular adaptability makes SF a unique matrix that is both bioactive and intelligent. Advances in hydrogel engineering have transformed SF from a passive scaffold into a smart, living hydrogel. These systems can instruct cell fate, sense microenvironmental signals, and deliver therapeutic signals as needed. By incorporating stem cells, progenitors, or engineered immune and microbial populations, SF hydrogels now serve as synthetic niches for organoid maturation and as adaptive implants for tissue regeneration. These platforms replicate extracellular matrix complexity and evolve with tissue, showing self-healing, shape-memory, and stimuli-responsive properties. Such features are redefining biomaterial–cell interactions. SF hydrogels are used for wound healing, musculoskeletal repair, neural and cardiac patches, and developing scalable organoid models for disease and drug research. Challenges remain in maintaining long-term cell viability, achieving clinical scalability, and meeting regulatory standards. This review explores how advances in SF engineering, synthetic biology, and organoid science are enabling SF-based smart living hydrogels in bridging the gap between research and clinical use. Full article

(This article belongs to the Special Issue Hydrogel-Based Scaffolds with a Focus on Medical Use (3rd Edition))

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20 pages, 4858 KB

Open AccessArticle

Effect of Ultrasound on the Microbial Flora and Physicochemical Parameters of Yogurt Added to Native Mexican Plants

by Luis M. Carrillo-López, Ismael Ortíz-Aguirre, América Chávez-Martínez, Luis F. Salomé-Abarca, Lorena Luna-Rodríguez, Juan M. Vargas-Romero and Ramón M. Soto-Hernández

Gels 2025, 11(11), 907; https://doi.org/10.3390/gels11110907 - 13 Nov 2025

Viewed by 371

Abstract

There is a growing trend in food fortification to use natural products to improve quality during production and processing. We study the effect of high-intensity ultrasound (HIU), applied at different processing times to fresh raw cow’s milk supplemented with dried plant material (DPM), [...] Read more.

There is a growing trend in food fortification to use natural products to improve quality during production and processing. We study the effect of high-intensity ultrasound (HIU), applied at different processing times to fresh raw cow’s milk supplemented with dried plant material (DPM), on the gel fermentation kinetics and the physicochemical profile of yogurt during storage. The results showed a significant reduction in milk fermentation with the application of HIU after inoculation (INOC). The counts of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus increased with the use of HIU, producing a synergistic effect in the presence of DPM due to the phenolic acids and flavonoids present. Syneresis was reduced and the water holding capacity (WHC) significantly increased in gels obtained with milk to which DPM had been added and which was sonicated after INOC. This led to the formation of a denser and more homogeneous protein network that retained more serum during storage. The luminosity of gels produced with milk sonicated at 40 °C increased, improving their appearance. However, saturation was reduced, shifting the yellow color to a neutral hue. In gels produced with non-sonicated milk, the fat separated, forming a yellow upper layer. HIU applied after INOC in milk to which DPM had been added reduced the milk processing time, producing stable and better-quality yogurts during refrigerated storage. Full article

(This article belongs to the Special Issue Food Gels: Fabrication, Characterization, and Application (2nd Edition))

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14 pages, 9095 KB

Open AccessArticle

Facile Preparation of Glass Fiber Wool/MTMS Aerogels with Improved Thermal Insulation and Safety

by Yong Ren, Huanlin Zhang, Xingwei Jiang, Miao Liu and Zhi Li

Gels 2025, 11(11), 906; https://doi.org/10.3390/gels11110906 - 12 Nov 2025

Viewed by 350

Abstract

With the continuous increase in global energy consumption and the escalating severity of climate change, the development of high-performance thermal insulation materials is crucial for reducing energy waste and carbon emissions. In this work, a facile method was proposed to prepare thermal-insulating glass [...] Read more.

With the continuous increase in global energy consumption and the escalating severity of climate change, the development of high-performance thermal insulation materials is crucial for reducing energy waste and carbon emissions. In this work, a facile method was proposed to prepare thermal-insulating glass fiber wool/methyltrimethoxysilane aerogel (GFWA) composites through vacuum-assisted impregnation. The obtained results indicated that GFWA composites exhibited excellent thermal insulation and hydrophobic properties, with GFWA-30 containing 30 wt.% glass fiber wool having a thermal conductivity of 35.3 mW/m·K and a water contact angle of 125.8°. Additionally, the Young’s modulus of this composite was 21.2% higher than that of MTMS aerogel. In terms of thermal safety performance, compared to methyltrimethoxysilane aerogel, the GFWA-30 composite showed reductions of 21.6%, 18.8%, and 27.95% in peak heat release rate, total heat release, and gross calorific value, respectively. This study offers a simple and feasible approach to fabricating high-performance thermal insulation materials, which display huge potential for widespread application in the fields of building insulation and other fields with thermal insulation requirements. Full article

(This article belongs to the Special Issue Synthesis and Emerging Applications of Novel Aerogel Materials)

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20 pages, 3073 KB

Open AccessReview

Recent Advances in Functional Nanomaterials for Enhancing Biopolymer-Based Active Food Packaging: A Review

by Rui Zhang, Chuanhuan Liu, Congyu Lin, Hong Zhang, Longwei Jiang and Yingzhu Liu

Gels 2025, 11(11), 905; https://doi.org/10.3390/gels11110905 - 11 Nov 2025

Viewed by 494

Abstract

Food packaging serves a pivotal role in daily life, facilitating the efficient transportation of food and extending its shelf life. Petroleum-derived plastic packaging is extensively employed; however, its non-biodegradable nature poses significant environmental pollution and ecological degradation. Natural polymers (e.g., proteins such as [...] Read more.

Food packaging serves a pivotal role in daily life, facilitating the efficient transportation of food and extending its shelf life. Petroleum-derived plastic packaging is extensively employed; however, its non-biodegradable nature poses significant environmental pollution and ecological degradation. Natural polymers (e.g., proteins such as gelatin and corn gluten protein; polysaccharides including pectin, chitosan, starch, cellulose, and alginate) and synthetic polymers (e.g., polyvinyl alcohol, polylactic acid, and polyhydroxyalkanoates) can be utilized to fabricate food packaging films, thereby achieving green and eco-friendly objectives. Nevertheless, the inferior mechanical strength and inadequate antibacterial activity of biopolymer-based packaging have restricted their practical applications. In recent years, nanomaterials (e.g., nanoparticles, nanotubes, nanofibers, and nanosheets) have been employed to enhance the performance of food packaging, emerging as a research hotspot. Notably, nanoparticles possess unique properties, including a high specific surface area, excellent dispersibility, and multifunctionality, which enables them to be easily incorporated into film matrices. Owing to their unique chemical structures, nanoparticles form strong interactions with film matrices, leading to a denser spatial structure. This not only markedly enhances the mechanical strength of the films, but also simultaneously improves their antibacterial and antioxidant capabilities. This review classifies and summarizes common nanomaterials based on their chemical compositions, providing a theoretical foundation and technical reference for the future development and application of nanomaterials in the field of bio-based active food packaging. Full article

(This article belongs to the Special Issue Food Gels: Structure and Function (2nd Edition))

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