Gels, Volume 11, Issue 10 (October 2025) – 80 articles

New compostable materials have been developed to replace single-use soft materials such as polyurethane foams (PUR). To this end, eco-friendly systems have been formulated on the basis of agar gels prepared in mixed solvent (glycerol/water) to meet specifications, i.e., stiffness of several hundred kPa, reasonable extensibility, and good stability when exposed to open air. While the addition of glycerol slows down gelation kinetics, mechanical properties are improved up to a glycerol content of 80 wt%, with enhanced extensibility of the gels while maintaining high Young’s moduli. Swelling analyses of mixed gels, in water or pure glycerol, demonstrate the preservation of an energetic network, with no change in volume, in pure water and the transition towards an entropic network in glycerol related to the partial dissociation of helix bundles. Dimensional and mechanical analysis of gels aged in an open atmosphere at room temperature shows that the hygroscopic character of glycerol enables sufficient water retention to maintain the physical network, with antagonistic effects linked to relative increases in glycerol, which tends to weaken the network, and agar, which on the contrary strengthens it. Complementary analyses carried out on aged agar gels formulated with an initial glycerol/water mass composition of 60/40, the most suitable for the targeted development, enabled the comparison of the properties of agar gels favorably with those of PURs and verified their stability during long-term storage, as well as their non-toxicity and compostability. Full article

This article presents the results of a study on the rheological characteristics of in situ thermosensitive nasal gels based on poloxamer 407 (P407) and their effect on spray angle. The development of new drug delivery systems based on in situ thermosensitive gels can overcome several shortcomings of traditional nasal sprays associated with mucociliary clearance and low mucoadhesion. Using the cold method, samples based on P407 were prepared in pure form, in combination with poloxamer 188 (P188), and with the addition of several mucoadhesive polymers: chitosan, sodium alginate, and hydroxypropyl methylcellulose (HPMC). Analytical studies were carried out for all obtained samples, which showed that the gelling temperature (T_sol–gel) of compositions with P407 was inversely dependent on its concentration, decreasing from 32.71 °C to 24.63 °C. The addition of hydrophilic P188 increased T_sol–gel. The addition of mucoadhesive polymers had varying effects on T_sol–gel: chitosan and HPMC increased the temperature, while sodium alginate decreased it. The addition of mucoadhesive polymers significantly affected the viscosity of the formulations; for example, the addition of sodium alginate resulted in a fivefold increase, making the formulations unsuitable for spraying. A study of the spray angles of T_sol–gel samples in the range of 27–31 °C using the SprayVIEW measuring system revealed an inverse relationship between the viscosity of the formulations and the spray angle. A mathematical model of the solution droplet trajectory was presented, enabling the spray angle to be predicted depending on the formulation composition. The relative error of the computational experiments did not exceed 10%. This approach has the potential to reduce the number of full-scale experiments, and consequently their cost. Full article

The design of hydrogel-based materials for wound care management requires the integration of multiple functionalities, including the capacity to maintain hydration, to prevent infection, and to adapt to the dynamic wound microenvironment. In this study, we fabricated innovative pH-reactive multilayer hydrogel patches based on ionically crosslinked alginate and incorporated with bioactive compounds, including Manuka honey, hyaluronic acid, and Ribes nigrum extract. The multilayer structure is coated with chitosan to improve water affinity and pH response. The patches are designed to respond to variable pH conditions typical of wound environments, with potential applicability to burn wounds. The hydrogel materials are characterized in terms of water content, swelling behavior, and water vapor transmission rate (WVTR). The chitosan-coated multilayer hydrogel exhibited high water uptake (swelling ratio up to 22.11 ± 0.25; water content 95.48 ± 0.05%) and controlled WVTR (~3450–3850 g/m²·day⁻¹), while degradation remained below 42% at pH 8 compared to >80% in single layers. Microstructural analysis is performed via optical microscopy to assess the morphology and uniformity of the multilayer system, while chemical characterization is conducted using Fourier-transform infrared (FTIR) spectroscopy. The results highlight the ability of the designed material to respond to pH variations and to accommodate bioactive agents within a structurally stable and hydrated network, suggesting its suitability for future investigations into controlled release applications. Full article

The rational design of advanced composite gels requires rigorous rheological analysis to decode their flow-deformation mechanisms, a prerequisite for optimizing performance in food and biomedical applications. However, systematic thermal analysis and rheological profiling of Salecan/Sanxan hydrogels remain unexplored, constituting a critical knowledge gap in this field. This study engineered Salecan/Sanxan hydrogels and systematically probed Salecan-dependent rheological and thermal properties. Through Power Law and Herschel–Bulkley model analyses, the hydrogels demonstrated composition-dependent rheological properties: yield stress (4.7–29.2 Pa), η₅₀ (342.6–3011.4 mPa·s), and Arrhenius equation fitting revealed tunable activation energy (14,688.3–30,997.1 J·mol⁻¹). Notably, when the gel was formulated with 3% Sanxan and 2% Salecan at a volume ratio of 1:2, its thermal-decomposition temperature rose by 9%, from 224.4 °C to 245.1 °C. Conversely, a 1:1 mixture of 2% Sanxan and 2% Salecan produced the lowest freezing point recorded (–18.3 °C), an 18% reduction compared with the control (–15.4 °C). These findings demonstrate the tunable rheological and thermal properties of Salecan/Sanxan hydrogels. By establishing that precise modulation of polymer mixing ratios can match the entire processing shear spectrum, this study not only fills a critical knowledge gap but also creates a versatile platform for designing tailor-made foods and biomedical matrices. Full article

Hydrogels based on poly (methacrylic acid), carboxymethyl cellulose, and nanocellulose fibers were successfully synthesized, characterized, and tested as topical carriers for the controlled release of hydrophobic resveratrol and hydrophilic acetyl glucosamine, active substances used in skin protection. Carrier composition was confirmed by Fourier-transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) revealed the pore size variations with alterations in the neutralization degree of methacrylic acid and changes in the pore-wall roughness caused by different mass fractions of nanocellulose. The neutralization degree of methacrylic acid had a substantial impact on the swelling behaviour, while only a slight change in swelling was caused by various contents of nanocellulose in hydrogels. Mechanical properties of the hydrogels accessed by compressive strength measurement at various percentages of strain were improved by the addition of nanocellulose. Hydrogels containing 0.5% nanocellulose achieved the highest compressive strength. The neutralization of methacrylic acid reduced the mechanical properties. Hydrogels with optimal properties showed outstanding potential in encapsulation, and controlled the simultaneous release of resveratrol and N-acetyl glucosamine. The different nature of the active compounds, however, affected the release kinetics and mechanism, as confirmed by the Korsmeyer–Peppas model. Full article

Hydroxyapatite (HA) coatings improve implant bioactivity but suffer from brittleness and limited functionality. Here, we report a hybrid coating strategy combining flame-sprayed HA/TiO₂ with in situ hydrogel growth. TiO₂ incorporated into the HA matrix acted as a photocatalytic initiator for acrylamide polymerization under UV. Unlike conventional hydrogel coatings that require added photoinitiators or separate surface modification steps, TiO₂ incorporated into the HA layer serves as a built-in photocatalytic initiator, enabling direct polymerization of acrylamide monomers on the sprayed surface. The resulting HA/TiO₂–hydrogel coatings exhibited a continuous hydrogel layer with intimate contact to the ceramic surface, as evidenced by SEM cross-sections and elemental mapping. The HA/TiO₂ 1% coating produced a continuous coverage in close contact with the surface, while excessive TiO₂(5%) led to uncontrolled hydrogel growth and partial coating failure. SEM cross-sections revealed a dense, well-adhered coating with homogeneously distributed Ca, P, O, and finely dispersed Ti. Upon immersion in simulated body fluid (SBF), submicron globular deposits progressively developed on the coating surface. EDS showed an increase in Ca/P ratio from ~1.66 (as-sprayed) to ~1.92 (14 days). These findings highlight a straightforward approach for combining flame-sprayed ceramics with photocatalytic hydrogel growth, providing a practical route toward multifunctional implant surface modification. Full article

The food packaging industry is inclined toward biodegradable films, and jellyfish hold significant potential for exploitation due to their extraordinary collagen content. Thus, the primary objective of this research was to develop an antioxidant gelatine-based film from the blue cannonball jellyfish (Stomolophus sp. 2) (JG), using chitosan (CH) and the casting method, with glycerol (GLY) as a plasticiser to improve film flexibility. The JG obtained through alkaline, heat, and dialysis treatment exhibited high in vitro antioxidant activity. A commercial chitosan acetic acid solution (1%) was added to a JG water solution (1%) and a commercial gelatine (CG) solution (1%) was employed as a control. The film’s mass ratio was 4:1:2 (JG:CH:GLY). The physical, chemical, thermal, mechanical, and antioxidant properties of the JG-CH and CG-CH films were compared; JG-CH showed higher solubility and thermal stability than CG-CH. The colour and light transmittance were similar; however, their tensile strength and elongation differed. Furthermore, JG-CH films exhibited a higher ABTS radical-scavenging capacity compared to CG-CH films. FTIR and ¹H NMR spectra of the JG-CH films indicated excellent compatibility between the components, primarily due to hydrogen bonding. This study demonstrates that JG-CH films possess functional properties that make this material suitable for application as a biomaterial film for food. Full article

This study reports the use of an in situ-forming gel based on hyaluronic–chitosan–glycerophosphate for wound healing. Hydrogels with optimized thermoresponsive gelling, rheological, and prolonged drug release properties were developed and incorporated with ciprofloxacin and carvacrol. In vitro evaluations included rheological studies, swelling degree, degradation rates, morphological analysis, antioxidant effects, antimicrobial activity, and drug release studies. The effectiveness of the optimized hydrogel was assessed using an animal ischemic wound rabbit ear model. The incorporation of ciprofloxacin and carvacrol into the combined hydrogel system maintained the mechanical strength of the formula, with a G′/G″ ≈ ratio of approximately 15.6, interconnected porosity, and controlled swelling. It enhanced antimicrobial activity against both S. aureus and E. coli. In addition, the developed gel exhibited sustained release following the Higuchi diffusion kinetics. The quantitative wound area% indicated that on day 9, the mean wound area decreased from 81.8% for the control to 51.2% for the developed gel. The study findings demonstrate the suitability and potential of this system as multifunctional wound-healing formulations that promote moist healing, antimicrobial and antioxidant activities, while providing sustained therapeutic delivery over 24 h. Full article

Second-degree burns are common dermal injuries requiring effective interventions to promote timely and complete skin regeneration. This study evaluated the wound-healing efficacy of topical hydrogels containing powdered licorice root (Glycyrrhiza glabra L.) extract at concentrations of 5%, 10%, and 20% w/w in a standardized murine model. Female SKH-hrHR2 hairless mice (n = 8 per group) were subjected to second-degree thermal burns, and treatment hydrogel formulations were applied once daily under occlusive dressings. Wound healing was assessed by planimetric area measurements, transepidermal water loss (TEWL), and histopathology. By Day 19, complete wound closure was achieved in 87.5% of animals in the 5% group, compared with 50.0% in the 10% group, 37.5% in the 20% group, and 25.0% in the sodium alginate control (Fisher’s exact test, p = 0.008). TEWL remained unchanged in the 5% group (baseline vs. Day 19: 8.4 ± 1.2 vs. 8.6 ± 1.3 g/m²/h; p > 0.05) but increased significantly in all other groups (e.g., sodium alginate: 8.2 ± 1.1 to 13.5 ± 2.0 g/m²/h; p = 0.0001). Histologically, the 5% formulation showed near-normal epidermal architecture and minimal inflammation (mean total score 2.0) compared with higher concentrations (6.0 for 10% and 7.3 for 20%) and sodium alginate (8.3). These findings demonstrate that a 5% Glycyrrhiza glabra hydrogel provides, among the concentrations studied here, the most favorable balance of wound closure, barrier restoration, and histological recovery, supporting its further development as a topical therapy for second-degree burns. Full article

Cancer is a prevalent disease worldwide. Photodynamic therapy (PDT) is a non-invasive and highly targeted treatment for certain types of cancer. Recently, it has been combined with nanotechnology, e.g., nanogel, for enhancing its therapeutic efficacy. “Curcumin” is a more typical naturally occurring photosensitizer (PS) in PDT, due to its wide range of pharmacological activities, including anticancer, anti-inflammatory, antibacterial, and antiviral effects. However, curcumin has low bioavailability, limiting its therapeutic potential, which can be improved with the help of nanotechnology. Growing evidence has shown that curcumin-loaded nanogels have their specific functions, such as drug delivery and cancer targeting. Curcumin-loaded nanogel has overcome the limitations of free curcumin, such as solubility and controlled release, with the help of these, as they provide a multifunctional platform to enhance the therapeutic effects of PDT. However, it is still required to further investigate the combinations of curcumin, nanogel, and PDT. Much more work needs to be done, including safety assessments of curcumin-loaded nanogel with PDT delivery systems, long-term toxicity on the human body, and optimization of dosage for curcumin, nanogels, PS, light parameters, and delivery mechanisms for the PDT process, as well as the exploration of tumor-specific targeting and immune response for humans, for example, adverse drug reactions or drug to herbal interaction. Full article

Heavy metal contamination in water, predominantly from copper (Cu(II)) ions, poses substantial risks to human and environmental health. This study developed a novel, robust adsorbent known as a carboxylate cellulose nanocrystal–silica–graphene oxide hybrid composite porous monolith, which effectively removes Cu(II) from water in a rapid manner. Carboxylate cellulose nanocrystals with enhanced metal-binding properties were synthesized from cellulose extracted from sugarcane bagasse, a significant agricultural byproduct. The porous monolith was synthesized through the combination of carboxylate cellulose nanocrystals, tetraethyl orthosilicate (TEOS), and graphene oxide, utilizing a sol–gel method. The efficacy of the synthesis was confirmed using Fourier-Transform Infra-red (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET) analyses. The material exhibited a highly porous mesoporous structure with a surface area of 512 m²/g, signifying a significant enhancement. Batch adsorption experiments under optimal conditions (pH = 5.5, contact time = 240 min, initial concentration = 200 mg/L) demonstrated a high experimental adsorption capacity of 172 mg/g for Cu(II). The adsorption process was best described by the Langmuir isotherm model, which yielded a theoretical maximum capacity (q_m) of 172 mg/g, and the pseudo-second-order kinetic model, confirming monolayer coverage and chemisorption as the rate-limiting step. Thermodynamic analyses demonstrate that the process is both spontaneous and exothermic. The porous monolith demonstrates the capability for multiple uses, maintaining over 70% efficiency after five cycles. The findings indicate that the carboxylate cellulose nanocrystal–silica–graphene oxide hybrid composite porous monolith is an efficient and robust method for the remediation of copper-contaminated water. Full article

Background: Skin infections caused by Staphylococcus aureus represent a major public health concern, and plant extracts, such as those from Cochlospermum regium, have emerged as promising therapeutic alternatives. Methods: This study developed carbopol-based gel formulations containing ethanolic leaf extracts of C. regium (CRG 0.5% and 1%) and evaluated their physicochemical stability, antibacterial activity against S. aureus and a methicillin-resistant wound isolate, antioxidant potential, and biocompatibility. Results: Both CRG 0.5% and 1% were physically stable and maintained antibacterial activity for up to 90 days at 8 °C, while at 25 °C only CRG 1% retained activity throughout the evaluation period. In ex vivo pig skin assays, CRG 1% reduced methicillin-resistant S. aureus contamination by 99%, outperforming the conventional topical antibacterial agent (neomycin + bacitracin), which achieved 66% inhibition. The extract also exhibited high antioxidant activity without mutagenic or hemolytic effects. Although phenolic and flavonoid contents decreased over time, CRG 1% preserved adequate levels for therapeutic application. Conclusions: These findings indicate that CRG 1% has potential as a stable, safe, and effective alternative for the treatment of topical infections, particularly those caused by methicillin-resistant S. aureus. Full article

To address limitations such as cleaning difficulties or secondary contamination/damage of cultural relics caused by the uncontrollable diffusion of water/cleaning agent/dirty liquids during the cleaning process in traditional cleaning methods, this study, using cotton textiles as an example, systematically investigated the cleaning efficacy of four in situ methods (blank gel, cleaning gel, ultrasonic emulsification, and gel + ultrasonic emulsification synergistic cleaning) on eight types of stains, including sand, clay, rust, blood, ink, oil, and mixed solid/liquid stains. Building upon this, this study proposed an efficient, targeted, in situ, and controllable cleaning strategy tailored for fragile, stained textile relics. Results demonstrated that, regardless of the stain type, the synergistic cleaning method of G+U (gel poultice + ultrasonic emulsification) consistently outperformed the cleaning methods of blank gel poultice, cleaning gel poultice, and ultrasonic emulsification. Furthermore, the gel loaded with cleaning agents was always more effective than the blank gel (unloaded cleaning agents). The poultice methods of blank gel and cleaning gel were better suited for solid stains, while the ultrasonic emulsification cleaning method was more effective for liquid stains. Meanwhile, it was also found that the optimal cleaning method proposed in this study (the G+U synergistic cleaning method) was a cleaning method that restricted the cleaning agent within the gel network/emulsion system, and utilized the porous network physical structure of gel, the chemical action of emulsion’s wetting/dissolving dirt, and the cavitation synergistic effect of ultrasound to achieve the targeted removal of contaminants from relics’ surfaces. Crucially, the cleaning process of G+U also had the characteristics of controlling the cleaning area at the designated position and effectively regulating the diffusion rate of the cleaning solution within the treatment zone, as well as the reaction intensity. Therefore, the proposed optimal (the synergistic cleaning method of G+U) cleaning method conforms to the significant implementation of the “minimal intervention and maximal preservation” principle in modern cultural heritage conservation. Consequently, the synergistic cleaning method of G+U holds promise for practical application in artifact cleaning work. Full article

Inulin, a type of fructan primarily extracted from chicory, Jerusalem artichoke, and dahlia, is a prebiotic dietary fiber increasingly valued for its multifunctional roles in food systems. Beyond its well-established nutritional benefits linked to gut microbiota modulation and metabolic health, inulin also provides unique techno-functional properties that make it a versatile structuring ingredient. This review emphasizes inulin’s ability to form gel-like networks and emulsion gels, examining the mechanisms of gelation and the influence of chain length, degree of polymerization, and processing conditions on gel stability and performance. Inulin-based gels act as effective fat replacers, texture modifiers, and carriers of bioactive compounds, supporting the reformulation of foods with reduced fat and sugar while maintaining desirable texture and sensory quality. Applications span a wide range of food systems, including dairy, meat, bakery, confectionery, plant-based, and gluten-free products, where inulin contributes to enhanced structure, stability, and palatability. Furthermore, the potential to obtain inulin from agro-industrial by-products strengthens its role in sustainable food design within a circular economy framework. By integrating nutritional, structural, and technological functionalities, inulin and inulin-based gels emerge as promising tools for the development of innovative and health-oriented food products. Full article

Ethnographic collections often incorporate composite objects consisting of various materials, including wood, textiles and metals. These objects are vulnerable to deterioration when iron fastenings corrode under humid environments, and their removal is therefore essential for the long-term preservation of artifacts. This study investigates the efficacy of the chelating agents Desferrioxamine B (DFO-B) and ethylenediaminetetraacetic acid (EDTA), applied in different gel formulations, in cleaning wooden and textile mock-ups stained with iron corrosion products. Three gel types were explored: xanthan gum, agarose and Nanorestore extra-dry gel with medium water retention (nano-MWR). The results indicated that xanthan gum exhibited the highest cleaning effectiveness but posed risks of residue deposition and surface damage due to the required clearance process. Agarose and nano-MWR gels proved to be less effective but showed potential for achieving high chelator efficacy with repeated applications. Agarose enhanced the chelators’ efficacy on textiles, while nano-MWR gel performed better on even wooden surfaces. No chemical damage was detected for either substrate across gel applications. The study concludes that a single gel formulation does not achieve equivalent cleaning efficacy on the two substrates of composite objects with a defined number of applications. Agarose in a semi-rigid state enhances the efficacy of textile treatment and may achieve comparable results on wood after repeated applications. Alternatively, a combined approach using agarose for textiles and nano-MWR gel for wood may optimize chelator performance on composite artifacts. Full article

Monitoring the time-dependent rheological properties of 3D printed MgO-SiO₂-K₂HPO₄ is critical for optimizing the dynamic structural reconstruction ability. The collaborative analysis for the contribution of colloidal force based on EDLVO theory and the volume fraction of K-struvite (MgKPO₄·6H₂O) was conducted. Results showed that 20% silica fume (SF) was identified as the optimal content to achieve balanced rheo-mechanical performance (28 d compressive strength = 113.63 MPa, dynamic yield stress = 359.98 Pa, thixotropic area = 2.14 × 10⁴ Pa/s). The static yield stress development within 50 min exhibited two distinct stages: the initial rapid linear growth stage (Stage I, 5–30 min) dominated by colloidal forces (R² = 0.81 at 20% SF), followed by the slow increased plateau (Stage II, 30–50 min) correlated with K-struvite volume fraction. Also, dual crystallization pathways of K-struvite included direct precipitation from supersaturated Mg²⁺, K⁺, PO₄³⁻ ionic species and transformation from potassium-deficient phosphate phase. Quantitative results establish a predictive framework for microstructural construction, enabling precise control of structural build-up and 3D printability in MgO-SiO₂-K₂HPO₄ cementitious composites. Full article

Hydrogel/electrospun polymer nanofiber composites (HENC) integrate the advantages of both components. Hydrogels provide high water content, biocompatibility, and tunable drug release, while electrospun nanofibers offer a high surface area, loading capacity, customizable morphology, and opportunities for functionalization. Nanofibers can also be incorporated into hydrogels as 3D-printable inks. Together, these features create biomimetic composites that modulate drug release and mimic native tissues. This article reviews electrospinning fundamentals, limitations, preparation methods for HENC, and their applications in drug delivery, as well as future perspectives for developing advanced functional materials with improved therapeutic efficacy, controlled release kinetics, and broad biomedical adaptability. Full article

The development of biodegradable films with antioxidant properties offers a promising approach to food preservation. This study focused on creating and characterising mango starch-based films enriched with mango peel extract (MPE) at concentrations of 0, 1, and 2%, using peels from mangoes (Mangifera indica var. Corazon) at organoleptic maturity, obtained as residual byproducts (peel and seed) for active food packaging applications. An MPE extraction yield of 35.57 ± 2.74% was achieved using ultrasound-assisted extraction (UAE), confirming its rich phenolic content and antioxidant activity as a natural alternative to synthetic preservatives. Rheological analysis revealed that the films exhibited pseudoplastic behavior, with complex viscosity reducing as angular frequency increased. Incorporating MPE at concentrations up to 1% enhanced the films’ viscoelastic properties, while a 2% addition significantly altered their frequency and temperature dependence. The rheological modeling showed that the fractional Maxwell model with two springpots described the films more accurately than the generalized Maxwell model. This approach offered a clearer understanding of their viscoelastic response, especially under changes in frequency and temperature. Mechanical characterization indicated that adding MPE improved film strength while reducing solubility. Although film thickness remained unchanged, increasing MPE concentration led to greater opacity and darker coloration. These changes offer advantages in food packaging by enhancing UV protection and reducing oxidative degradation. Crucially, the incorporation of MPE significantly increased the phenolic content and antioxidant capacity of the films, as confirmed by ABTS assays. These findings strongly support the potential of MPE-based films for active packaging, providing a sustainable and functional alternative for preserving light-sensitive food products. Among the tested formulations, films with 1% MPE demonstrated the most effective balance of rheological stability, mechanical strength, and antioxidant capacity. Full article

Hydroxypropyl methylcellulose (HPMC) is a biocompatible polymer widely used in topical formulations due to its suitable rheological behavior, film-forming capacity, and good compatibility with different active pharmaceutical ingredients. The present study demonstrates the potential of HPMC-based gels for dermal delivery of porphyrinic photosensitizers, aiming to enhance the efficiency of photodynamic therapy (PDT) in potential skin cancer applications. HPMC-based gel incorporating two previously synthesized porphyrinic photosensitizers, named 5,10,15,20-tetrakis-(4-acetoxy-3-methoxyphenyl) porphyrin (P2.1) and 5-(4-hydroxy-3-methoxyphenyl)-10,15,20-tris-(4-acetoxy-3-methoxyphenyl) porphyrin (P2.2), was developed and carefully characterized regarding its rheological behavior, texture, and in vitro activity. Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), atomic force microscopy (AFM), fluorescence, and UV-Vis spectroscopy were carried out to evaluate the structural and morphological changes induced by the incorporation of the porphyrins in the HPMC gel matrix. The gels were subsequently evaluated by pharmacotechnical analysis, including pH (7.2 for both HPMC-P2.1 and HPMC-P2.2), viscosity, spreadability, texture profile analysis, and drug content uniformity. Rheological behavior confirmed the pseudoplastic behavior, suggesting a structured system with a gel-like consistency, while physical measurements demonstrated the stability and preserved functionality of the photosensitizers within the HPMC matrix. In vitro studies revealed an efficient cellular internalization of selected porphyrins into human epidermoid carcinoma cells, a critical requirement for topical PDT applications. The study highlights the capability of HPMC gels to serve as effective delivery platforms for porphyrin-based photosensitizers, supporting their application in localized skin cancer treatment through PDT. Full article

Bigels are promising delivery systems for bioactive compounds, combining the properties of hydrogels and oleogels. Pequi carotenoids, characterized by their natural yellow fluorescence, hold potential to replace the artificial dye tartrazine in foods while simultaneously enhancing their functional properties. This study developed food-grade bigels with varying oleogel-to-hydrogel ratios (40%, 60%, 80% OG) to assess the pigmentation capacity of pequi carotenoid extracts. Hydrogel contained agar and xanthan gum, while oleogel comprised beeswax, lecithin, sunflower oil, and 400 μg/100 g carotenoid extract. Bigel color was analyzed using the CIELAB system. Linear and multiple regression models were applied to assess the influence of crosslinking time (1 vs. 12 h), extraction solvent (acetone vs. [BMIM][BF4]), saponification, and oleogel ratio on color parameters. The color of the carotenoid-enriched bigels was mainly influenced by the extraction solvent and the oleogel ratio, while saponification and crosslinking time had only minor impacts. Although changes in L*, a*, and b* were observed across samples, ΔE* values generally reflected low perceptibility. Notably, more evident color differences were associated with variations in solvent type and oleogel ratio. These findings contribute to a better understanding of how formulation parameters influence the pigmentation behavior and support the development of natural, visually appealing functional foods. Full article

Electronic skins (E-skins) are the integration of intelligent wearable sensors that can collect human physiological, motion, or environmental parameters in real-time through flexible, sensitive materials. The performance of E-skins depends on the selection of materials to a large extent. Hydrogel materials are an excellent candidate for E-skin preparation due to their tissue-like softness and biocompatibility. However, their low electrical conductivity, weak mechanical strength, and environmental instability seriously hinder high-fidelity signal acquisition and reliable operation in practical applications. To overcome these bottlenecks, conductive composite hydrogels have emerged as a promising alternative material. The unique properties of conductive composite hydrogels, such as high stretchability, self-healing ability, and adjustable electrical conductivity, address the relevant issues of traditional hydrogels in wearable applications. This review focuses on conductive composite hydrogels for wearable E-skins. Firstly, the types, characteristics, and preparation strategies of hydrogel matrix materials are introduced. Subsequently, the performance regulation mechanisms of key conductive fillers on composite hydrogels are discussed. Then, the application progress in electrophysiological signal monitoring, human–machine interaction, and human motion monitoring is reviewed. Finally, the current challenges and future development directions of hydrogel-based E-skins are prospected, aiming to provide comprehensive material and fabrication references for the practical application of composite hydrogel in electronic skins. Full article

This study presents an enantiomeric-ratio-driven strategy for constructing mechanically robust supramolecular gels using cyclohexane bisurea derivatives. By employing non-equimolar enantiomeric mixtures, we achieved an ultralow critical gelation concentration (CGC < 2 mg/mL) in toluene, representing a reduction of more than fivefold compared to homochiral single-enantiomer systems. Rheological measurements revealed substantially enhanced mechanical properties in the non-equimolar gels, with yield stress and storage modulus values up to 17 and 20 times higher, respectively, than those of single-enantiomer gels. Morphological analyses (SEM and POM) indicated that pure enantiomers form isolated crystalline fibers with limited connectivity, whereas racemic mixtures yield disordered amorphous aggregates. In contrast, non-equimolar mixtures self-assemble into hierarchical “sea urchin-like” architectures, wherein crystalline fibers radiate from central cores to form densely interconnected networks. This unique structural motif underpins both the ultralow CGC and superior mechanical performance. Complementary FT-IR, XRD, and DSC analyses demonstrated that chiral imbalance modulates hydrogen-bonding interactions and structural order, while molecular dynamics (MD) simulations provided insight into the divergent self-assembly pathways among homochiral, racemic, and non-equimolar systems. This work provides a stereochemically guided approach for designing high-performance supramolecular gels with tailored hierarchical structures and enhanced functionality. Full article

This study aimed to minimize the amount of gelator used in oleogel preparation and enhance the valorization of rubber seeds. Cellulose extracted from rubber seed shells was modified via high-pressure microfluidization (HPM), which significantly enhanced its specific surface area from 0.92 m²/g (CL) to 6.47 m²/g (MCL), along with markedly improved water-holding capacity (WHC increased from 4.92 to 29.37 g/g) and swelling capacity (SC increased from 0.65 to 3.38 mL/g). The modified cellulose (MCL) served as the gelator, while rubber seed oil bodies (OBs), isolated through sucrose-assisted extraction, functioned as the oil phase. A series of OB emulsions containing 0% to 0.75% MCL were prepared and subsequently converted into oleogels by freeze-drying and shearing. Oleogels containing ≥0.45% MCL exhibited excellent oil binding capacity (OBC > 98.6%) and strong gel strength (storage modulus G′ > 10⁵ Pa). Texture profile analysis further confirmed significant improvements in the textural properties of the oleogels with increasing MCL content. These findings demonstrate that MCL, combined with rubber seed OBs, enables the development of high-performance oleogels with minimal gelator requirements. This approach not only reduces gelator usage but also provides a novel strategy for the upcycling of rubber seed shells, offering valuable insights for the design of nutrient-rich functional oleogels. Full article

To address the limitations of traditional chemical flooding—such as high cost, environmental impact, and formation damage—and the challenges of standalone microbial flooding—including preferential channeling, microbial loss, and limited sweep efficiency—this study develops a novel composite system for a high-permeability heavy oil reservoir. The system integrates a 3% scleroglucan + 1% phenolic resin gel (ICRG) with Bacillus licheniformis (ZY-1) and a surfactant. Core flooding and two-dimensional physical simulation experiments reveal a synergistic mechanism: The robust and biocompatible ICRG gel effectively plugs dominant flow paths, increasing displacement pressure fourfold to divert subsequent fluids. The injected strain ZY-1 then metabolizes hydrocarbons, producing biosurfactants that reduce oil–water interfacial tension by 61.9% and crude oil viscosity by 65%, thereby enhancing oil mobility. This combined approach of conformance control and enhanced oil displacement resulted in a significant increase in ultimate oil recovery, achieving 15% and 20% in one-dimensional and two-dimensional models, respectively, demonstrating its substantial potential for improving heavy oil production. Full article

The accurate determination of the equilibrium moisture content (EMC) of gel-related powdery samples requires strictly controlled conditions and a long time period. In this study, the adsorption and desorption isotherms of two fructooligosaccharide (FOS) powders and three inulin powders were determined using a dynamic moisture sorption analyzer at 0.1–0.9 water activity (a_w) and 20–35 °C, respectively. The adsorption and desorption isotherms all exhibited type IIa sigmoidal curves; the desorptive isotherm was smooth, the FOS adsorption curves had three inflection points, and the inulin adsorption curves had five inflection points. Large hysteresis between the adsorption and desorption isotherms occurred at 0.1–0.7 a_w for FOS and 0.1–0.6 a_w for inulin. Seven equations, Boquet, Ferro–Fontan, Guggenheim–Anderson–de Boer (GAB), Generalized D’Arcy and Watt (GDW), modified GAB (MGAB), Peleg, and our developed Polynomial, were found to fit the isotherms of the FOS and inulin samples; for adsorption, the best equations were Ferro–Fontan and GDW, and for desorption, the best equations were Polynomial and MGAB. The GDW and MGAB equations could not distinguish the effect of temperature on the isotherms, while the Polynomial equation could. The mean adsorptive monolayer moisture content (M₀) values in FOS and inulin samples were predicted as 7.29% and 7.94% wet basis, respectively. The heat of moisture sorption of FOS and inulin approached that of pure water at about 32.5% and 22.5% wet basis (w.b.) moisture content (MC), respectively. Fourier Transform Infrared Spectroscopy (FTIR) showed that the peaks in inulin with absorbance values above 0.52 and in FOS with absorbance values above 0.35 were at 1020, 1084, and 337 cm⁻¹; these could represent the amorphous structure (primary alcohol C-OH), C-O group, and hydroxyl functional group, respectively. Microscopic structure analysis showed that inulin powder particles were more round-shaped and adhered together, resulting in hygroscopic and sticky characteristics, with a maximum equilibrium moisture content (EMC) of 34% w.b. In contrast, the FOS powders exhibited irregular amorphous particles and a maximum EMC of 60% w.b. As hydrogels, 3–10% FOS or inulin addition reduced the peak, trough, final, breakdown, and setback viscosities of rice starch pasting, but increased the peak time and pasting temperature. FOS addition gave stronger reduction in the setback viscosity and in amylose retrogradation of rice starch pasting than inulin addition. The differential scanning calorimeter (DSC) showed 3–10% FOS addition reduced the amylopectin aging of retrograded paste of rice starch, but 5–7% inulin addition tended to reduce. These results suggest that FOS and inulin have strong hygroscopic properties and can be used to maintain the freshness of starch-based foods. These data can be used for drying, storage, and functional food design of FOS and inulin products. Full article

Cannabidiol (CBD) and its derivatives show interesting therapeutic potential, including antioxidant, anti-inflammatory, and anticancer properties; however, their clinical translation remains a complex task due to physicochemical restrictions such as low water solubility, high lipophilicity, and instability under light, oxygen, and high temperatures. Polymeric encapsulation has emerged as a promising strategy to overcome these challenges, offering protection against environmental degradation, improved bioavailability, and controlled release. Natural and synthetic polymers, both biocompatible and biodegradable, provide versatile matrices for CBD delivery, enabling nanoparticle formation, targeted transport, and enhanced pharmacokinetics. This review highlights the structural characteristics of CBD, its interaction mechanisms with polymeric matrices such as hydrogels, electrospun nanofibers, biodegradable microparticles, thin films, and lipid-polymer hybrid systems, and the principal encapsulation techniques, such as emulsion solvent evaporation, electrospinning, and supercritical fluid technologies, that facilitate stability and scalability. Furthermore, material characterization approaches, including microscopy, thermal, and degradation analyses, are discussed as tools for optimizing encapsulation systems. While notable advances have been made, key challenges remain in achieving reproducible large-scale production, ensuring regulatory compliance, and designing smart polymeric carriers personalized for specific therapeutic contexts. By addressing these gaps, polymer-based encapsulation may unlock new opportunities for CBD in pharmaceutical, nutraceutical, and therapeutic applications, providing a guide for future innovation and translation into effective patient-centered products. Full article

Spatially fractionated radiotherapy (SFRT) is emerging as a powerful tool in cancer therapy for patients who are ineligible for treatment with clinically established irradiation techniques. Microbeam radiotherapy (MRT) is characterized by spatial dose fractionation in the micrometre range. This presents challenges in both treatment planning and dosimetry. While a dosimetry system with a spatial resolution of 10 µm and an option for real-time readout already exists, this system can only record dose in a very small volume. Thus, we are exploring dosimetry in an N-isopropylacrylamide (NIPAM) gel as an option for 3D dose visualization and, potentially, also three-dimensional dosimetry in larger volumes. In the current study, we have recorded the geometric patterns of single- and multiport irradiation with microbeam arrays in NIPAM gel. Data for 3D dose distribution was acquired in a 7T small animal MRI scanner. We found that the resolution of the gel is well suited for a detailed 3D visualization of microbeam patterns even in complex multiport geometries, similar to that of radiochromic film, which is well established for recording 2D dose distribution in MRT. The results suggest that a dose–response calibration is required for reliable quantitative dosimetry. Full article

Periodontitis is a chronic oral inflammatory disease whose treatment is often hindered by poor drug retention, prolonged therapeutic regimens, and the rise of antibiotic resistance. In this study, we developed a Hydrogel@ZIF-8@metronidazole (Hydrogel@ZIF-8@MNZ) nanocomposite dressing for targeted, sustained, and in situ antimicrobial therapy. This system integrates ZIF-8, a pH-responsive metal–organic framework, with the antimicrobial agent metronidazole (MNZ), encapsulated within a crosslinked hydrogel matrix to enhance stability and retention in the oral environment. Drug release studies demonstrated that MNZ release was significantly accelerated under acidic conditions (pH 5.0), mimicking the periodontal microenvironment. The Hydrogel@ZIF-8 composite achieved a maximum MNZ adsorption capacity of 132.45 mg·g⁻¹, with a spontaneous and exothermic uptake process best described by a pseudo-second-order kinetic model, suggesting chemisorption as the dominant mechanism. The nanoplatform exhibited strong pH-responsive behavior, with enhanced drug release under acidic conditions and potent dose-dependent bactericidal activity against Fusobacterium nucleatum (Fn). At the highest tested concentration, bacterial survival was reduced to approximately 30%, with extensive membrane disruption observed through live/dead fluorescence microscopy. In summary, the stimuli-responsive Hydrogel@ZIF-8@MNZ nanocomposite offers an intelligent and effective therapeutic strategy for periodontitis. By tailoring its action to the disease microenvironment, this platform enables sustained and localized antibacterial therapy, addressing major challenges in the treatment of chronic oral infections. Full article