Search Results (2,159)

The objective of this study was to evaluate the effects of hydrogel polymer application on the antioxidant activity and physiological performance of colored-fiber cotton cultivars grown under different levels of water restriction. Two experiments were conducted under greenhouse conditions. In the first experiment, the effects of the hydrogel polymer, cultivars, and irrigation replacement levels were evaluated; in the second, the residual effect of the hydrogel polymer applied in the first experiment was assessed using the same cultivars and irrigation depths. Water restriction negatively affected relative water content, gas exchange, chlorophyll a fluorescence, and antioxidant activity, and increased electrolyte leakage in cotton cultivars. Water deficit reduced relative water content, gas exchange, chlorophyll a fluorescence, and antioxidant activity, while increasing electrolyte leakage in the cultivars. However, hydrogel polymer application up to 6.5 g dm⁻³ of soil and its residual effect in subsequent cycles were beneficial. The polymer increased relative water content and antioxidant activity, in addition to improving gas exchange and chlorophyll fluorescence, suggesting maintenance of plant physiological health. Residual polymer doses also enhanced relative water content, antioxidant activity, gas exchange, and chlorophyll fluorescence in plants during Experiment II. Full article

Alginate-based hydrogels, derived from brown seaweed, represent biocompatible and biodegradable materials whose properties are systematically controlled through molecular structure (M/G composition), crosslinking strategy, and compositional modification. This review synthesizes recent advances in alginate hydrogel design, encompassing fundamental structural properties, three primary crosslinking approaches—ionic coordination with divalent cations (Ca²⁺, Ba²⁺, Sr²⁺), covalent chemical linkages, and hybrid multi-crosslinking systems—and strategic modification strategies including chemical derivatization, polymer blending, and nanoparticle incorporation. These modifications address inherent limitations of native alginate, namely insufficient mechanical strength and biological inertness, thereby expanding applicability. The review examines applications across biomedical domains (drug delivery, tissue engineering, wound healing), environmental remediation, food industry systems, and emerging technologies including flexible electronics and soft robotics. Advanced fabrication techniques—3D/4D printing, microfluidics, and electrospinning—enable improved architectural control. Current evidence from preclinical and clinical studies demonstrates feasibility in specific applications, while important challenges persist, including predictable degradation kinetics, mechanical property optimization, standardization of characterization protocols, regulatory compliance, and manufacturing scalability. This review aims to provide a systematic assessment of alginate-based hydrogel development and identify areas requiring further investigation to advance clinical translation. Full article

Post-cholecystectomy non-alcoholic fatty liver disease (NAFLD), now encompassed within metabolic dysfunction-associated steatotic liver disease (MASLD), is increasingly linked to persistent disruption of bile acid kinetics and gut–liver axis signaling after gallbladder removal. Continuous bile delivery to the intestine reshapes the bile acid pool, perturbs FXR–FGF19/TGR5 pathways, remodels gut microbiota, and compromises epithelial barrier integrity, collectively promoting portal endotoxemia, chronic hepatic inflammation, and fibrogenic remodeling. Hydrogel-based biomaterials offer a mechanistically aligned therapeutic platform for this setting because they enable localized, sustained, and stimuli-responsive interventions at intestinal or hepatic sites. Functional hydrogels can sequester excess bile acids, protect and deliver probiotics/prebiotics/postbiotics, reinforce mucosal barrier function, and provide controlled release of anti-inflammatory or antifibrotic agents with reduced systemic exposure. In this review, we map emerging hydrogel strategies relevant to post-cholecystectomy NAFLD across four pathogenic nodes, bile acid dysregulation, dysbiosis, inflammation, and fibrosis, and highlight design principles (polymer chemistry, charge/hydrophobicity balance, mucoadhesion, and pH/redox/enzyme responsiveness) that enable targeted modulation of the gut–liver axis. Finally, we identify key translational gaps, including the lack of post-cholecystectomy-specific experimental models and standardized outcome measures integrating bile acid profiling, microbiome readouts, and hepatic histology. Hydrogel technologies represent a promising route toward localized and multimodal therapy in metabolic liver disease, warranting focused preclinical validation and clinical development. Full article

The rapid growth of electronic devices, including wearable sensors, has increased electronic waste, driving interest in sustainable, biocompatible materials. Electrospun biomaterials have emerged as versatile substrates for multifunctional wearable textiles, offering flexibility, high surface area, tunable porosity, and biocompatibility. Using natural polymers (e.g., silk fibroin, cellulose, chitosan) and synthetic polymers (e.g., polycaprolactone, polylactic acid, PVDF), electrospinning produces nanofibrous mats capable of supporting thermal regulation, moisture management, and integrated sensing for pressure, temperature, humidity, or chemical detection. Nature-inspired designs, hybrid composites, and advanced architectures enable passive and active thermoregulation via phase-change materials, thermochromic dyes, hydrogels, and conductive nanofibers, while maintaining wearer comfort, breathability, and skin safety. Despite progress, challenges persist in durability, washability, energy efficiency, manufacturing scalability, and recyclability. This review provides a comprehensive overview of biomaterials, fabrication techniques, multifunctional sensor integration, and thermoregulation strategies, highlighting opportunities for next-generation wearable textiles that combine sustainability, adaptive thermal management, and high-performance sensing. Full article

The application of MXene–polymer composites to wearable and implantable medical devices requires the development of hydrophilic and biocompatible MXene–polymer hydrogel composites with high electromechanical response, flexibility, and durability. Here, we formulate low weight percentage MXene–hydrogel copolymer inks enabling the direct light processing (DLP) of Ti₃C₂T_x MXene–polyvinyl alcohol (PVA)–polyacrylic acid (PAA)–hydrogel composites. The low wt% MXene–PVA–PAA composites demonstrate high biocompatibility, mechanical flexibility, high sensitivity and high precision for sensing acute bending angles. The sub-millidegree angle resolution of these electromechanical sensors demonstrates their suitability for applications such as the highly precise tracking of joint movements. In addition, the synthesized MXene membranes show promise for applications in osmotic energy conversion, with a harvested electric power density of 6.79 Wm⁻². Full article

Hyperelastic models for the deformation of hydrogels were evaluated as alternatives to the widely used neo-Hookean model. Poly(ethylene glycol diacrylate) (PEGDA) was synthesized via photopolymerization, with precursor molecular weights from 700 to 4000 Da and synthesis concentrations between 5 and 30 wt% in water. Hydrogels are often modeled as neo-Hookean solids; this model holds only over a limited strain range. To model deformation over a broader range and seek additional insight into gel network structures, the Mooney–Rivlin, Ogden, Rubinstein–Panyukov, and Localization models were applied to uniaxial compression data and their fits assessed against “Mooney plots” of reduced stress versus the inverse extension ratio. The Ogden model best fits the stress–strain curves to higher ratios and the reduced stress plots over the broadest range of formulations. The Localization and Rubinstein–Panyukov models fit well above c*, the overlap concentration, capturing low-strain behavior and the observed maxima under compression in Mooney plots. The Mooney–Rivlin model fit the stress–strain curves but was unable to fit the reduced stress plots. The Localization and Rubinstein–Panyukov model parameters suggest that entanglements play a significant role at all concentrations, with their contribution decreasing as the network concentration increases. This demonstrates the potential of using two-parameter models to understand the deformation of hydrogels. Full article

Polypropylene (PP) nonwoven is widely used in biomedical textiles because of its lightweight and mechanical durability; however, its inherent hydrophobicity and chemical inertness limit further surface functionalization. In this study, a plasma-assisted UV grafting strategy was developed to fabricate thermo-responsive and antibacterial hydrogel coatings on PP nonwoven. Atmospheric-pressure plasma jet (APPJ) treatment was first employed to activate the PP nonwoven surface, followed by UV-induced graft polymerization of chitosan and N-isopropylacrylamide (NIPAAm), forming a chitosan-co-PNIPAAm hydrogel immobilized on the nonwoven substrate. Surface characterization using water contact angle measurement, Fourier transform infrared spectroscopy, and scanning electron microscopy confirmed effective plasma activation and successful hydrogel grafting. APPJ treatment significantly enhanced surface wettability, whereas subsequent UV grafting formed a continuous hydrogel on the PP nonwoven surface. The modified nonwoven exhibited distinct thermo-responsive swelling behavior in aqueous and simulated physiological environments, associated with the temperature-sensitive characteristics of the PNIPAAm component. In addition, the incorporation of chitosan imparted pronounced antibacterial activity against Escherichia coli, with inhibition zone diameters ranging from 14 to 16.5 mm, indicating high antibacterial sensitivity. Preliminary cytocompatibility evaluation further demonstrated favorable cell viability on the modified surfaces. This study demonstrates a scalable and low-temperature surface engineering approach for integrating stimuli-responsive and antibacterial hydrogel functionality into nonwoven polymer substrates, offering potential for advanced biomedical textile applications. Full article

Polymer functionalization is rapidly emerging as a transformative strategy for enhancing nanocatalysts by reprogramming the catalytic interface, rather than simply modifying the active phase. This approach leverages the unique tunability of polymers through their chemistry, thickness, permeability, charge density, and ionic/electronic conductivity to stabilize nanophases, regulate local microenvironments, and manage mass transport. These properties significantly improve catalytic activity, selectivity, and long-term durability. This review provides an in-depth examination of key construction strategies for polymer-functionalized nanocatalysts, categorizing them into six primary platforms: neutral functional polymers, ionomers/polyelectrolytes, conductive polymers, crosslinked networks/hydrogels, hybrid polymers, and framework polymers. Additionally, we explore recent advances in electrocatalysis, photocatalysis, and thermocatalysis, addressing challenges such as the trade-off between protection and accessibility, polymer stability under extreme conditions, and the need for standardized reporting of polymer descriptors. By framing polymers as programmable interfacial materials, this review highlights their potential to unlock significant improvements in catalytic performance across various catalytic systems. Full article

Stimuli-responsive textiles are a rapidly evolving class of functional fiber-based materials that sense and adapt to environmental triggers. Within these enabling technologies, hydrogels and microcapsules are very illustrative, as they offer complementary mechanisms for moisture management, controlled release, and adaptive performance. Hydrogels provide soft, water-rich polymer networks with modifiable swelling, permeability, and mechanics, while microcapsules offer protection and targeted delivery of active agents through engineered shell structures. When integrated into fibrous networks, they impart dynamic detection responses for moisture, temperature, pH, mechanical stress, light, and chemical or biological agents. This review critically examines progress in design, synthesis, and textile integration of hydrogel- and microcapsule-based systems, with emphasis on materials that exhibit stimuli-responsive behavior rather than passive or extended-release functionality. Strategies for incorporating bulk hydrogels, micro- and nanogels, and stimuli-responsive microcapsules into fibers, yarns, and fabrics are discussed in addition to applications such as smart apparel, medical and hygienic textiles, controlled drug delivery, antimicrobial fabrics, and adaptive filtration media. Existing challenges for durability, washability, response kinetics, scalability, and sustainability are highlighted, while future research directions are proposed to advance the development of robust and intelligent textile systems at the nexus of soft matter science and fiber engineering. Full article

The valorization of wine by-products aligns with circular bioeconomy principles. This study investigates the ultrasound-assisted aqueous extraction (UAE) of bioactive compounds and cell wall polysaccharides from Syrah grape stems (Vitis vinifera L.) to produce polysaccharide extracts with the intrinsic potential to form cellulose-rich gels with enhanced antioxidant properties. Extractions were performed at three temperatures (10, 20, and 50 °C) and three ultrasonic power densities (120, 206, and 337 W/L), and compared to conventional extraction (CE, 200 rpm). The results demonstrated that UAE significantly accelerated the extraction kinetics for total phenolics (TP), flavonols, and antioxidant capacity (ABTS, FRAP), achieving up to a 3.1-fold increase in TP yield at 20 °C. Notably, UAE at 337 W/L and 20 °C produced antioxidant levels equivalent to those obtained by CE at 50 °C, enabling high efficiency at lower, compound-preserving temperatures. Carbohydrate analysis revealed that the extracts were inherently “cellulose-rich” (glucose ~49–52 mol%), with co-extracted pectins and hemicelluloses constituting a composite polysaccharide matrix with inherent gel-forming capacity, as evidenced by its composition. While total polysaccharide yield was maximized at 10 °C, UAE’s primary effect was the facilitation of extraction and potential structural modification of polymers rather than increasing bulk yield. The process reduced extraction times by 3- to over 6-fold to achieve equivalent bioactive yields compared to CE. This work establishes UAE with water as a process aligned with green chemistry principles, an efficient strategy for the integrated, one-step recovery of antioxidant phenolics and gel-forming polysaccharides from grape stems, transforming this underutilized residue into a multifunctional extract precursor for cellulose-rich hydrogels suitable for food and pharmaceutical applications. Full article

Chitosan is a natural biopolymer for advanced wound healing due to its antimicrobial activity, biocompatibility, and hemostatic properties. However, its clinical utility is limited by its low solubility and poor mechanical properties. This review summarizes recent strategies that have successfully overcome these shortcomings, focusing on the development of multifunctional chitosan hybrid dressings. These dressings, which include hydrogels, hydrocolloids, films, sponges, and scaffolds, are now being fabricated using advanced systems like electrospinning, 3D printing, microneedle (MN), and nanocomposites technologies to maximize wound healing efficacy. Specifically, modification techniques used to overcome chitosan’s shortcomings include: (1) chemical derivatization to enhance solubility, (2) polymer hybridization with natural and synthetic materials to enhance mechanical properties, and (3) functionalization with active ingredients. These materials, including metal/inorganic nanoparticles, natural compounds, and amino acids, are added to maximize therapeutic efficacy. In conclusion, chitosan hybrid materials and dressings provide an excellent foundation for next-generation wound dressings. However, overcoming challenges associated with material diversity and establishing standardized manufacturing processes and clinical trials remain critical for successful commercialization. Full article

Microbial biofilms pose significant health risks by causing infections associated with prosthetic and indwelling medical devices. Factors such as the high tolerance levels of biofilm microorganisms to antibiotics and the inability of antimicrobial agents to penetrate the biofilm matrix render antibiotic-based treatment methods ineffective against biofilm-related infections. Surfaces patterned with nanoscale topographical features have shown promising results in controlling the attachment of microorganisms. Therefore, nanopatterning of surfaces provides an excellent alternative to the existing antibiotic-based therapies. There are many techniques, such as photolithography and soft lithography, for patterning polymer or metal surfaces. However, depending on the cost, toxicity, feature size, and material compatibility, these methods have limitations. Although hydrogels have garnered special interest as biomaterials due to their biocompatibility and resemblance to the natural biological environment, hydrogels with surface nanopatterns have not been widely investigated as anti-biofouling materials. The applicability of hydrogels in biomedical applications and the importance of inhibiting microbial biofilms underscore the need for further research into the manufacturing of nanoengineered hydrogels with diverse topographical features. In this review, we discuss how nanostructured hydrogels inhibit biofilm formation. Further, we discuss nanopatterning methods, their limitations, advantages, and disadvantages. This article also highlights the current state of research on nanostructured hydrogels and associated challenges. Full article

Stimuli-responsive hydrogels are an emerging class of smart materials with immense potential across biomedical engineering, soft robotics, environmental systems, and advanced manufacturing. In this review, we present an in-depth exploration of their material design, classification, fabrication strategies, and real-world applications. We examine how a wide range of external stimuli—such as temperature, pH, moisture, ions, electricity, magnetism, redox conditions, and light—interact with polymer composition and crosslinking chemistry to shape the responsive behavior of hydrogels. Special attention is given to the growing field of 4D printing, where time-dependent shape and property changes enable dynamic, programmable systems. Unlike existing reviews that often treat materials, stimuli, or applications in isolation, this work introduces a multidimensional comparative framework that connects stimulus-response behavior with fabrication techniques and end-use domains. We also highlight key challenges that limit practical deployment—including mechanical fragility, slow actuation, and scale-up difficulties—and outline engineering solutions such as hybrid material design, anisotropic structuring, and multi-stimuli integration. Our aim is to offer a forward-looking perspective that bridges material innovation with functional design, serving as a resource for researchers and engineers working to develop next-generation adaptive systems. Full article

Superabsorbent polymers (SAPs) are materials that can absorb and retain water solutions with a mass of several hundred times greater than their own. This work aimed to synthesise and evaluate the effects of highly absorbent starch phosphate-g-poly(acrylic acid) copolymers on the microbiological activity of soils previously used for agriculture. The biopolymers studied were obtained by thermal and chemical oxidation of starch phosphates and copolymerized with potassium salts of acrylic acid. Basic physicochemical parameters were determined in the applied soil. Following SAP application, the basal respiration rate was measured at 22 °C with a constant soil moisture content of 60% WHC. The incubation time in constant temperature and moisture conditions was 78 days. After this period, their microbiological activity (microbial and organic phosphorus fractions) was assessed, thereby enabling the determination of the direction of change in the soil environment. The addition of SAP increases the soil’s water-holding capacity and respiration. The SP-g-PAA polymers serve as slow-release sources of potassium and phosphorus ions. These elements were bound to the polymer network by ionic and covalent bonds. Analysis of the results shows that within two weeks, 47–80% of the starch hydrogel undergoes microbial degradation. No differences were found in the content of labile forms of phosphorus in soils with SAP additions compared to soils without polymer additions. The use of modified starch reduces the consumption of vinyl monomers, while the resulting product is characterised by high absorbency and low water content, which reduces the amount of energy needed to obtain the finished product, thus contributing to sustainable development. Full article

Fermented extracts of Flourensia cernua (F. cernua), enriched with bioactive polyphenols such as caffeic acid, apigenin, myricetin, and quercetin, exhibit strong potential to promote tissue regeneration. However, controlled delivery systems are required to enhance their bioavailability and therapeutic efficacy. In this study, F. cernua extracts (7–21 wt.%) were encapsulated in collagen hydrogels to develop bioactive matrices with sustained release properties. The hydrogel with 14 wt.% enabled sustained extract release from day 5 under physiological conditions and skin-mimicking pH (4.5). Increasing the extract concentration led to enhanced hydration behavior (>1400%) and crosslinking density (>45%), contributing to faster gelation. SEM analysis revealed fibrillar morphologies with amorphous globular domains whose prevalence increased with extract content and conferred improved thermal stability. Mechanical analysis indicated a decrease in matrix stiffness due to repulsive interactions between the extract components and the polymer network. Biodegradation studies showed slow hydrolytic and enzymatic degradation at skin pH in hydrogels containing 7 wt.% extract. All hydrogels demonstrated hemocompatibility, with no erythrocyte lysis. Moreover, hydrogels with 14 wt.% extract significantly enhanced the metabolic activity and proliferation of monocytes and fibroblasts, while 7 wt.% extract reduced TNF-α secretion, indicating anti-inflammatory potential. In vitro wound closure assays revealed 90% contraction within 10 days in fibroblast cultures exposed to 14 wt.% extract-loaded hydrogels. These results support the use of F. cernua-enriched collagen hydrogels as multifunctional scaffolds for wound healing and tissue regeneration. Full article