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Timely and effective interventions after tracheal mucosal injury are lack in clinical practices, which elevate the risks of airway infection, tracheal cartilage deterioration, and even asphyxiated death. Herein, we proposed a biomaterial-based strategy for the repair of injured tracheal mucosal based on a copper hydrogen phosphate nanosheets (CuHP NSs) functionalized commercial hydrogel (polyethylene glycol disuccinimidyl succinate-human serum albumin, PH). Such CuHP/PH hydrogel achieved favorable injectability, stable gelation, and excellent adhesiveness within the tracheal lumen. Moreover, CuHP NSs within the CuHP/PH hydrogel effectively stimulate the proliferation and migration of endothelial/epithelial cells, enhancing angiogenesis and demonstrating excellent tissue regenerative potential. Additionally, it exhibited significant inhibitory effects on both bacteria and bacterial biofilms. More importantly, when injected injured site of tracheal mucosa under fiberoptic bronchoscopy guidance, our results demonstrated CuHP/PH hydrogel adhered tightly to the tracheal mucosa. The therapeutic effects of the CuHP/PH hydrogel were further confirmed, which significantly improved survival rates, vascular and mucosal regeneration, reduced occurrences of intraluminal infections, tracheal stenosis, and cartilage damage complications. This research presents an initial proposition outlining a strategy employing biomaterials to mitigate tracheal mucosal injury, offering novel perspectives on the treatment of mucosal injuries and other tracheal diseases.

Bacterial nanocellulose (BNC) is a durable, flexible, and dynamic biomaterial capable of serving a wide variety of fields, sectors, and applications within biotechnology, healthcare, electronics, agriculture, fashion, and others. BNC is produced spontaneously in carbohydrate-rich bacterial culture media, forming a cellulosic pellicle via a nanonetwork of fibrils extruded from certain genera. Herein, we demonstrate engineering BNC-based scaffolds with tunable physical and mechanical properties through postprocessing. Human skeletal muscle myoblasts (HSMMs) were cultured on these scaffolds, and in vitro electrical stimulation was applied to promote cellular function for tissue engineering applications. We compared physiologic maturation markers of human skeletal muscle myoblast development using a 2.5-dimensional culture paradigm in fabricated BNC scaffolds, compared to two-dimensional (2D) controls. We demonstrate that the culture of human skeletal muscle myoblasts on BNC scaffolds developed under electrical stimulation produced highly aligned, physiologic morphology of human skeletal muscle myofibers compared to unstimulated BNC and standard 2D culture. Furthermore, we compared an array of metrics to assess the BNC scaffold in a rigorous head-to-head study with commercially available, clinically approved matrices, Kerecis Omega3 Wound Matrix (Marigen) and Phoenix as well as a gelatin methacryloyl (GelMA) hydrogel. The BNC scaffold outcompeted industry standard matrices as well as a 20% GelMA hydrogel in durability and sustained the support of human skeletal muscle myoblasts in vitro. This work offers a robust demonstration of BNC scaffold cytocompatibility with human skeletal muscle cells and sets the basis for future work in healthcare, bioengineering, and medical implant technological development.

Current study focuses on the development of a promising technique to prepare D-mannitol xanthate-based hydrogel (DMXAGAHs hydrogel) using a free radical co-polymerization technique for eliminating Cu2+ and Ni2+ ions from aqueous solutions. The UV, FTIR, TGA, ΔpHPZC and SEM analysis have been used for the characterization of the synthesized hydrogel. The percent swelling (%SR) of the prepared DMXAGAHs-3 hydrogel has been found to be 28,123, 13,433 and 11,177% and water retention ratio (%WRR) was 78.02, 78.84 and 79.22% for distilled water, tap water and gray wastewater. Additionally, the maximum metal ion removal was obtained as 96.9 for Cu2+ ions and 94.1% for Ni2+ ions by DMXAGAHs-3 hydrogel at optimum adsorbent dosage of 3.125 g/L, pH of 7, temperature 45 °C, initial concentration 1000 mg/L and contact time 60 min, respectively. The experimental data were found to be well-fitted with the Langmuir isotherm model. The optimal adsorption capacities of DMXAGAHs-3 hydrogel, as per the Langmuir model, were determined to be 371.74 mg/g for Cu2+ ions and 296.73 mg/g for Ni2+ ions, respectively. The pseudo-second-order kinetic model has been found to be the most suitable model for describing the kinetic behavior of the adsorption process. The rate constant according to this model has been found to be 3.0 × 10−4 g/(mg.min) for Cu2+ and 3.2 × 10−4 g/(mg.min) for Ni2+ ions, respectively. The negative ΔG values (− 5.567 kJ/mol for Cu2+ and − 4.647 kJ/mol for Ni2+ ion) at optimum temperature of 45 °C indicates that the adsorption process is spontaneous in nature along with positive ΔH values (79.80 and 25.38 kJ/mol for Cu2+ and Ni2+ ion) and ΔS values (267.81 and 100.51 J/Kmol for Cu2+ and Ni2+ ion) also suggests adsorption process is endothermic in nature and results in the increase in the degree of randomness of metal ions on the DMXAGAHs-3 hydrogel during the adsorption process. In addition, the DMXAGAHs-3 hydrogel has shown a remarkable desorption efficiency with 82.36 and 80.21% desorption for Cu2+ and Ni2+ ions even on 5th cycle and the hydrogel can be utilized many times for the adsorption of heavy metal ions. [ABSTRACT FROM AUTHOR]

Controlled drug delivery is the mechanism that determines the frequency of the drug as well as the side effect that can be occurred. Many approaches studied the encapsulation of the drug in a polymer matrix to achieve a controlled released drug by the effect crosslinking network. In this work, a loaded hydrogel with ciprofloxacin hydrochloride has been prepared as an incremental effect on the antibacterial properties. So, four formulations named, hydrogel 1, hydrogel 2, hydrogel 3, and hydrogel 4 were prepared using different polymers concentrations (chitosan, gelatin, iota carrageenan (IC), and glutaraldehyde as crosslinking agents) ciprofloxacin hydrochloride was used as a drug model. The obtained data revealed that the hydrogels prepared from chitosan/gelatin/IC hydrogels are porous and have interconnected microstructures. The hydrogels structure was evaluated by ATR-IR spectroscopy, EDX, Swelling rate, SEM, porosity, antibacterial properties as well as drug release and kinetics. The hydrogels fractured at stresses of 0.1665 to 0.0358 Kgf / mm2. The swelling rates (SR %) after 24 h. were 412%, 362%, 383%, 375% and 407% for of hydrogel 1, hydrogel 2, hydrogel 3, hydrogel 4 and ciprofloxacin hydrochloride loaded hydrogel 1, respectively. The porosity of the prepared hydrogels was increased as the concentration of IC increased from 72.4 to 78%. Loading of ciprofloxacin hydrochloride was confirmed by the presence of fluorine in the EDX measurement. The ciprofloxacin hydrochloride loaded hydrogel 1 has a sustained release of ciprofloxacin hydrochloride over a time of about 10 h. The first-order kinetic model is the best model for the release of ciprofloxacin hydrochloride from the prepared ciprofloxacin hydrochloride loaded hydrogel 1 with a regression coefficient (R2) of 0.9814. The unloaded samples of hydrogels had almost the same antibacterial properties regardless of the amount of IC. Loading the hydrogel with ciprofloxacin hydrochloride has an incremental effect on the antibacterial properties. [ABSTRACT FROM AUTHOR]

Electrochemical synthesis and characterization of Zn‐alginate hydrogel films and their antioxidant and antimicrobial activity are evaluated. Swelling properties, zinc concentration and spectroscopic and morphological features were characterized and related to their antimicrobial and antioxidant activity. These results indicate a dependence of swelling on the degree of cross‐linking, which, in turn, can be adjusted by manipulating the synthesis time, initial alginate concentration and/or zinc leaching. Hydrogel films with zinc showed remarkable antibacterial properties, especially against gram‐positive bacteria. The absence of Zn resulted in less inhibition of gram‐positive strains, although it had a positive effect on the inhibition of gram‐negative strains, which was attributed to the degradation of alginate chains, affecting cell metabolism. Nitrogen‐doped samples synthesized in rivanol‐containing solution exhibited globular morphology and higher antioxidant activity. The electrochemical synthesis enables the facile preparation of highly active alginate hydrogels for biomedical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Conductive hydrogels are pivotal for the advancement of flexible sensors, electronic skin, and healthcare monitoring systems, facilitating transformative innovations. However, issues such as inadequate intrinsic compatibility, mismatched mechanical properties, and limited stability curtail their potential, resulting in compromised device efficacy and performance degradation. In this research, we engineered functional hydrogels featuring a dual-crosslinked network composed of (PA/PVA)-P(AM-AA) to address these challenges. This design eliminates the need for conductive additives, thereby enhancing intrinsic compatibility. Notably, the hydrogels exhibit exceptional mechanical properties, with high tensile strength (∼700 %), Young's modulus (∼5.33 MPa), increased strength (∼2.46 MPa) and toughness (∼6.59 MJ m−3). They also achieve a compressive strength of ∼7.33 MPa at 80 % maximal compressive strain and maintain about 89 % transparency. Moreover, flexible sensors derived from these hydrogels demonstrate enhanced multimodal sensing capabilities, including temperature, strain, and pressure detection, enabling precise monitoring of human movements. The integration of multiple hydrogels into a three-dimensional sensor array facilitates detailed spatial pressure distribution mapping. By strategically applying dual-crosslinked network engineering and eliminating conductive additives, we have streamlined the design and manufacturing of hydrogels to meet the rising demand for high-performance wearable sensors. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Garlic protein is one of the main components of garlic. It has several beneficial characteristics. This study aimed to characterize a double crosslinked hydrogel formed with alginate, calcium ions (Ca2+), and garlic protein hydrolysates (GPH), and to develop hydrogel beads for targeted delivery of bioactive constituents to the gastrointestinal tract.The results indicated that the degree of GPH hydrolysis was approximately 3% following trypsin treatment. The inner structure of the double crosslinked hydrogel showed a honeycomb pattern, with solid‐like gel rheology and improved texture properties at a 4% (w/v) GPH concentration. The GPH‐based hydrogel beads demonstrated pH sensitivity, swelling in near‐neutral and alkaline environments, and the encapsulated paclitaxel (PTX) exhibited an amorphous phase with preferential release in intestinal conditions. The GPH group also achieved greater drug encapsulation efficiency than a soy protein hydrolysate (SPH) group, and proteomic analysis suggested that lower molecular weight and peptide charge favored the formation of peptide‐integrated double crosslinking hydrogels.This work indicated that GPH was helpful and could inspire the development of drug delivery systems involving GPH with the required mechanical strength and target‐release properties. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Psoriasis is chronic autoimmune inflammatory skin disorder affecting millions of people worldwide (2–3% of world population). Treatment of psoriasis ranges from use of topicals to biologicals. Although topical treatments are preferred for mild to moderate cases of psoriasis, the thickened, inflamed skin, and the absence of moisturizing properties make conventional topical treatment challenging, hindering the effective management of the condition. The hydrogel-based systems are reported to be excellent vehicles and carriers for overcoming the barriers in topical delivery of drugs by hydrating the thick plaques and providing controlled release of medicament into the tough scaly skin. Recently, many nanocarrier loaded hydrogels-based system has gained popularity for effective delivery of drugs across psoriatic skin. The present review focuses on psoriasis, the deviation from normal skin in psoriatic condition which renders the effective delivery of drugs through topical route a greater challenge and how hydrogels-based system can effectively help alleviate psoriasis through effective drug delivery across the hyperkeratinized skin. In summary, hydrogels have emerged as effective carriers in psoriasis treatment as they provide a soothing effect, better patient acceptance, good penetration, controlled, sustained, and even smart drug release thus providing relief along with treatment. [ABSTRACT FROM AUTHOR]

Recently, solar‐driven interfacial evaporation (SDIE) has been developed quickly for low‐cost and sustainable seawater desalination, but addressing the conflict between a high evaporation rate and salt rejection during SDIE is still challenging. Here, a spatial confinement strategy is proposed to prepare the gel composite solar evaporator (SCE) by loading one thin hydrogel layer onto the skeleton of a carbon aerogel. The SCE retains the hierarchically porous structure of carbon aerogels with an optimized water supply induced by dual‐driven forces (capillary effects and osmotic pressure) and takes advantage of both aerogels and hydrogels, which can gain energy from air and reduce water enthalpy. The SCE has a high evaporation rate (up to 4.23 kg m−2 h−1 under one sun) and excellent salt rejection performance and can maintain structural integrity after long‐term evaporation even at high salinities. The SDIE behavior, including heat distribution, water transport, and salt ion distribution, is investigated by combining theoretical simulations and experimental results. This work provides new inspiration and a theoretical basis for the development of high‐performance interfacial evaporators. [ABSTRACT FROM AUTHOR]

Hydrogels have been used in the clinic since the late 1980s with broad applications in drug delivery, cosmetics, tissue regeneration, among many other areas. The past three decades have witnessed rapid advances in the fields of polymer chemistry, crosslinking approaches, and hydrogel fabrication methods, which have collectively brought many new hydrogel products, either injectable or non‐injectable, to clinical studies. In an article published in 2020 entitled "Hydrogels in the clinic", we reviewed the clinical landscape and translational challenges of injectable hydrogels. Here, we provide an update on the advances in the field and also extend the scope to include non‐injectable hydrogels. We highlight recently approved hydrogel products, provide an update on the clinical trials of injectable hydrogels, and discuss active clinical trials of topically applied and implantable hydrogels. [ABSTRACT FROM AUTHOR]

The increasing interest in hydrogel matrices and their diverse applications has fueled extensive research. However, single‐component gels have a limited adjustable performance range, and multi‐component gels raise concerns about biological safety, hindering their widespread use. This study focuses on harnessing high‐speed shearing and ultrasound‐assisted methods to incorporate active natural Haematococcus pluvialis (HP), creating novel composite hydrogels in conjunction with biological macromolecule gellan gum, and eliminating the need for structural modifications or chemical crosslinking. Rich astaxanthin, proteins, polysaccharides, and other components in HP can fill and promote the formation of a unified functional network. The study aims to explore the potential of HP as a rheology regulator and investigate its impact on the rheological properties of the gels. Various rheological models, including Power‐Law, Herschel–Bulkley, and Arrhenius, were employed for comparative analysis. This pioneering report on gellan/HP hydrogels holds significant importance as they exhibit optimized elasticity, thermal stability, enhanced injectability, and self‐recovery, making them suitable for a wide range of applications in specialized medical food and biomedicine. [ABSTRACT FROM AUTHOR]

Although different chemistries for the spatio‐temporal localization of molecules and gradients of chemical signals within soft materials are now available, the achievement of spatio‐temporal patterns of mechanical properties in such materials and their characterization remain considerable challenges. This study presents the syntheses of two novel photo‐sensitive and thermoresponsive hydrogel systems, a photo‐stiffening and a photo‐softening hydrogel. Their potential for fabricating soft materials with patterned mechanical properties is then demonstrated by fabricating an actuator whose higher‐order bending properties can be switched on with light, and by encoding mechanical properties for digital information encryption and storage. Microindentation and a custom‐made data analysis software are essential for the characterization of all the materials. From a general perspective, this work opens a route to the fabrication of soft materials with patterned mechanical properties, addressing an important emerging challenge in soft materials science with applications in soft robotics and information encryption and storage. [ABSTRACT FROM AUTHOR]

BRAFV600E-mutant colorectal cancer (CRC) is resistant to most first-line therapeutics, including the BRAF inhibitor dabrafenib and epidermal growth factor receptor (EGFR) inhibitor cetuximab. Although copper depletion shows promise in reversing dabrafenib/cetuximab resistance in BRAFV600E-mutant CRC, its application is limited by the potential for excessive copper depletion in non-tumor objects. In this study, we have developed a hydrogel platform for confined copper depletion in BRAFV600E-mutant CRC cells, which effectively reverses dabrafenib/cetuximab resistance and enhancing therapeutic efficiency. The hydrogel platform enables precise intracellular copper depletion through localized administration, acidity-triggered drug release, and oxidized activation of a copper prochelator. The dosage of this prochelator is 37.5 μg/kg in mouse models, which is significantly lower than the commonly used tetrathiomolybdate. Furthermore, both dabrafenib and the prochelator are preloaded into acid-responsive nanoparticles before being embedded in the hydrogel matrix to facilitate efficient endocytosis and acid-activatable drug release. Confined copper depletion inhibits MEK1 signaling and suppresses the MAPK signaling pathway when combined with BRAF and EGFR inhibitors. Moreover, the hydrogel platform inhibits tumor growth and prolongs survival in subcutaneous and postsurgical models of BRAFV600E-mutant CRC. This study provides an innovative strategy for overcoming dabrafenib/cetuximab resistance in BRAFV600E-mutant CRC through precise intracellular copper depletion. A combinational therapeutic strategy was developed based on confined copper depletion to combat BRAFV600E-mutant colorectal cancer (CRC). Dabrafenib and a copper prochelator were loaded in acidity-responsive nanoparticles, and then loaded in peptide hydrogel along with cetuximab. The hydrogel platform conducted depletion of intracellular copper to block MAPK signaling pathway, thus reversing dabrafenib/cetuximab resistance in BRAFV600E-mutant CRC and improving therapeutic efficiency in mouse tumor models. [Display omitted] • Hydrogel platform enables confined copper depletion in BRAFV600E-mutant CRC. • Acidity-responsive nanoparticles deliver dabrafenib and copper prochelator to inhibit the MAPK signaling. • Hydrogel platform blocks MAPK signaling, reversing dabrafenib/cetuximab resistance. [ABSTRACT FROM AUTHOR]

The in-situ activation of adaptive immunity at the surgical site has demonstrated remarkable efficacy in inhibiting various forms of tumour recurrence and even holds the promise of a potential cure. However, extensive research and bioinformatic analysis conducted in this study have unveiled the formidable challenge posed by melanoma-intrinsic β-catenin signaling, which hinders the infiltration of cytotoxic T-lymphocytes (CTLs) and their subsequent anti-tumour action. To overcome this obstacle, a β-catenin antagonist called carnosic acid (CA) was co-assembled with a RADA-rich peptide to create a nanonet-derived hydrogel known as Supra-gelδCA. This injectable hydrogel is designed to be retained at the surgical site while simultaneously promoting hemostasis. Importantly, Supra-gelδCA directly releases CA to the site of residual tumour lesions, thereby enhancing infiltration of CTLs and subsequently activating adaptive immunity. Consequently, it effectively suppresses postoperative recurrence of skin cutaneous melanoma (SKCM) in vivo. Collectively, the presented Supra-gelδCA not only provides an efficacious immunotherapy strategy for regulating adaptive immunity by overcoming the obstacle posed by melanoma-intrinsic β-catenin signaling-induced absence of CTLs but also offers a clinically translatable hydrogel that revolutionizes post-surgical management of SKCM. [Display omitted] [ABSTRACT FROM AUTHOR]

Compression‐coated matrix tablets were developed to target budesonide (BUD) in the colonic region using methacrylic acid (MAA) grafted inulin (INU) and carboxymethyl cellulose (CMC). INU was grafted with MAA to impart anionic characteristics to the gum, making it feasible to form a hydrogel by cross‐linking with calcium gluconate (CG). The core matrix made up of MAA‐g‐INU alone disintegrated within 30 min and the core matrix made up of CMC alone completely released BUD within 6 h. The combination of MAA‐g‐INU and CMC produced a rigid matrix, which was able to completely release BUD after 7 h. Compression coating of the core tablets with MAA‐g‐INU and CMC did not release BUD in the first 4 h, and complete BUD release took place in the next 4 h. Compression coating led to the formation of a rigid and viscous gel layer outside the core matrices, which hindered BUD release. We conclude that compression coating with CG cross‐linked CMC and MAA‐g‐INU could be used as a matrix for colonic delivery of drugs. Highlights: Compression coated matrices were developed for colonic delivery of BUD.The matrix retained drug release up to 4 h in upper gastrointestinal tract (GIT).The matrix exhibited complete drug release in the next 4 h in the colon. [ABSTRACT FROM AUTHOR]

Cartilage damage and degeneration pose significant challenges in orthopedic medicine, innovative approaches for regenerative therapies. The hydrogel is designed to provide a supportive matrix for cell growth and differentiation while delivering therapeutic agents to promote tissue repair. Drug-loaded hydrogels have been extensively studied for cartilage regenerative medicine, offering promising results for tissue engineering and drug delivery applications. These hydrogels, composed of homopolymers and copolymers, can absorb water and create an appropriate microenvironment similar to the extracellular matrix (ECM). Various polymers and crosslinking methods are explored to optimize the hydrogel's mechanical properties, biocompatibility, and drug release kinetics. Additionally, the study investigates the efficacy of different drugs, growth factors, and bioactive molecules for enhancing chondrogenesis and cartilage regeneration within the hydrogel scaffold. The developed drug-loaded hydrogel holds great promise for addressing the unmet clinical need for effective cartilage regenerative therapies, offering potential advancements in orthopedic medicine. [ABSTRACT FROM AUTHOR]

Skin photoaging, caused by prolonged exposure to ultraviolet (UV) radiation, manifests as intricate biological transformations, encompassing oxidative damage and structural alterations. Despite a growing need for effective interventions, the existing therapeutic repertoire for treating skin photoaging remains constrained. Recent investigations have shifted focus towards the application of hydrogels as a novel avenue for addressing this concern. Various active substances can be combined with hydrogels for transdermal delivery, including compounds from the ocean, plants, cell active substances, which can promote skin UV damage repair mainly through antioxidant, anti-inflammatory and promote collagen production. This review seeks to offer a thorough summary of recent progress in employing hydrogels for addressing skin photoaging. Topics covered include the mechanism of skin photoaging, and emerging trends in hydrogel-based therapies for skin rejuvenation. The discussion also explores challenges and outlines potential future directions in leveraging hydrogels as therapeutic agents to address skin photoaging. [ABSTRACT FROM AUTHOR]

Realization of scalable technologies for key processes like electrochemical water splitting requires the development of sustainable, efficient and cost‐effective catalytic electrodes. The innumerable electrocatalysts being developed in contemporary research rely on the use of a limited choice of binders for effective deployment in the electrolysis setting. Recent studies have demonstrated the utility of electrically insulating hydrogel polymers as suitable matrices for incorporating the electrocatalyst nanoparticles; the nanocomposite thin films coated on conducting substrates mediate highly efficient electrocatalytic water splitting reactions through the effective confinement of the electrolyte within and release of the gaseous products. After a brief introduction to the basic challenges in the field and the existing approaches that address them, this article outlines the promise of hydrogel based nanocomposite thin films in developing efficient and sustainable catalytic electrodes for water splitting, and their functional role in enhancing the efficiency of the electrochemical process. Directions for further development in this domain are noted. [ABSTRACT FROM AUTHOR]

A series of hybrid hydrogels of poly(ethylene glycol) (PEG) were synthesized using gelatin as a crosslinker and investigated for controlled delivery of the first-generation cephalosporin antibiotic, Cefazedone sodium (CFD). A commercially available 4-arm-PEG–OH was first modified to obtain four-arm-PEG–succinimidyl glutarate (4-arm-PEG–SG), which formed the gelatin–PEG composite hydrogels (SnNm) through crosslinking with gelatin. To regulate the drug delivery, SnNm hydrogels with various solid contents and crosslinking degrees were prepared. The effect of solid contents and crosslinking degrees on the thermal, mechanical, swelling, degradation, and drug release properties of the hydrogels were intensively investigated. The results revealed that increasing the crosslinking degree and solid content of SnNm could not only enhance the thermal stability, swelling ratio (SR), and compression resistance capacity of SnNm but also prolong the degradation and drug release times. The release kinetics of the SnNm hydrogels were found to follow the first-order model, suggesting that the transport rate of CFD within the matrix of hydrogels is proportional to the concentration of the drug where it is located. Specifically, S1N1-III showed 90% mass loss after 60 h of degradation and a sustained release duration of 72 h. The cytotoxicity assay using the MTT method revealed that cell viability rates of S1N1 were higher than 95%, indicating excellent cytocompatibility. This study offers new insights and methodologies for the development of hydrogels as biomedical composite materials. [ABSTRACT FROM AUTHOR]

Zinc-ion batteries (ZIBs) emerge as leading candidates for a flexible energy storage system, distinguished by high capacity, affordability, and inherent safety. The integration of hydrogel electrolytes, particularly those with saturated aqueous solvents, has significantly enhanced the electrochemical performance of ZIBs while preserving their essential flexibility. Nonetheless, challenges in electrochemical performance under specific conditions highlight the nascent stage of this technology, with numerous technical hurdles awaiting resolution. Addressing these challenges, recent investigations have leveraged the unique properties of cellulose hydrogel—namely, its exceptional toughness, tensile strength, extreme temperature resilience, stimulus responsiveness, and self-healing capabilities—to innovate multifunctional flexible zinc-based batteries. This paper conducts a comprehensive review of the physicochemical attributes of cellulose hydrogel electrolytes within ZIBs. We thoroughly analyze their performance under diverse environmental conditions, offering insights into the current landscape and their future potential. By examining these aspects, we aim to underscore the developmental prospects and the challenges that lie ahead for hydrogel electrolytes in ZIBs, paving the way for further advancement in this promising field. [ABSTRACT FROM AUTHOR]

Soluble biochemical agents are being employed to generate kidney organoids from human‐induced pluripotent stem cells. However, this soluble factor approach does not consider the effect of the mechanical environment on lineage commitment. Here, a mechanoresponsive nano‐environment with cell‐adhesive properties composed of supramolecular hydrogelators that co‐assemble into fibrous superstructures to form a transient network is presented, which is used to encapsulate kidney organoids. The delayed sol‐gel transition of the transient network enables fibrous superstructures to diffuse into the densely packed extracellular organoid space during the encapsulation procedure. This allows the mechanoresponsive matrix to induce a biological response beyond the organoid‐hydrogel border, and tune glomerulogenesis inside kidney organoids. In this manner, biomaterials are used as a complementary tool to soluble biochemical agents in tuning lineage commitment and refining organoid maturation. [ABSTRACT FROM AUTHOR]

AbstractThe Guar Gum Xanthate based hydrogel GGmX-g-poly(AA-co-HEMA) has been successfully synthesized by using the graft copolymerization of two monomers, acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) hydrogel. The synthesis follows the free-radical graft polymerization method. UV-visible spectroscopy (UV), Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Point zero charge (PZC), and field emission scanning electron microscopy (FESEM) were employed for the characterization of the synthesized hydrogel. This hydrogel has shown a high swelling ratio of 430.2 g/g and retention of 75.82% in distilled water which is a notable result. By using GGmX-g-poly(AA-co-HEMA) hydrogel, the maximum percentage of heavy metal ions removal from wastewater was found to be 98.5(±1.5)% and 97.1(±1.5) at optimum pH 6 and 6.5 for Cu2+ and Ni2+ solutions respectively. The Langmuir adsorption isotherm fits best for the adsorption data indicating a monolayer adsorption with maximum adsorption capacity of 423.72 (±26.1) mg/g and 404.85 (±31.4) mg/g for Cu2+ and Ni2+ ions respectively. The pseudo-second-order kinetic model provides the most accurate depiction of adsorption kinetics with rate constant 9.1 × 10−4 (±1.37×10−4)g/(mg.min) for Cu2+ and 8.3 × 10−4 (±1.24×10−4)g/(mg.min) for Ni2+ ions, respectively. The negative ΔG value (-4.75 kJ/mol for Cu2+ and −3.26 kJ/mol for Ni2+ ions) and positive value of ΔH (57.55 (±5.41) kJ/mol for Cu2+ and 40.60(±5.37) kJ/mol for Ni2+ ions) suggested the process to be spontaneous, endothermic, and feasible. It has been found that the hydrogel has excellent regenerative capacity with the % adsorption has been found to be 84.8% for Cu2+ and 82.4% for Ni2+ ions for the fifth cycle. [ABSTRACT FROM AUTHOR]

Introduction: Multidomain peptides (MDPs) are amino acid sequences that self-assemble to form supramolecular hydrogels under physiological conditions that have shown promise for a number of biomedical applications. K2(SL)6K2 ("K2"), a widely studied MDP, has demonstrated the ability to enhance the humoral immune response to co-delivered antigen. Herein, we sought to explore the in vitro and in vivo properties of a peptide with the same sequence but opposite chirality (D-K2) since peptides composed of D-amino acids are resistant to protease degradation and potentially more immunostimulatory than their canonical counterparts. Methods: K2 and D-K2 hydrogels were characterized and evaluated in vitro using circular dichroism, rheology, cryo-electron microscopy, and fluorescence recovery after photobleaching studies. In vivo experiments in SKH-1 mice were conducted to evaluate both ovalbumin release from the hydrogels and hydrogel degradation. The injection site of the hydrogels was analyzed using histology and humoral immunity was assessed by ELISA. Results: In vitro, the enantiomeric hydrogels exhibited similar rheological properties, and fluorescence recovery after photobleaching experiments demonstrated that the diffusion of ovalbumin (OVA), a model antigen, was similar within both hydrogels. In vivo, K2 and D-K2 peptide hydrogels had similar OVA release rates, both releasing 89% of the antigen within 8 days. Both hydrogels elicited a similar antigen-specific humoral immune response. However, the in vivo degradation of the D-K2 hydrogel progressed significantly slower than K2. After 4 weeks in vivo, only 23 ± 7% of the K2 hydrogel remained at the injection site compared to 94 ± 7% of the D-K2 hydrogel, likely due to their different protease susceptibilities. Conclusion: Taken together, these data suggest that peptide chirality can be a useful tool for increasing hydrogel residence time for biomedical applications that would benefit from long persistence times and that, if an antigen releases over a sufficiently short period, release can be largely independent of degradation rate, though slower-diffusing payloads may exhibit degradation rate dependence. [ABSTRACT FROM AUTHOR]

Background: Alarming data revealed that 19% to 34% of adults with diabetes mellitus develop chronic wounds, which are characterized by impaired healing and a higher risk of infections. Inspired by the traditional use of immortelle for wound healing and the lack of scientific evidence regarding how it thoroughly influences tissue regeneration, we aimed to formulate a hydrogel loaded with immortelle essential oil and assess its effectiveness on diabetic excision wounds. Methods: The rheological properties of the hydrogel, an in vivo safety test, as well as wound healing capacity, were determined in rats with induced diabetes and excision wounds. Diabetic rats were divided into four groups: untreated, treated with 1% silver sulfadiazine ointment, treated with a gel base, and treated with the immortelle essential oil-based hydrogel. Results: It was revealed that the hydrogel exerts pseudoplastic behavior and has no potential to act as an irritant, thus highlighting its suitability for skin application. Moreover, analysis of macroscopic, biochemical, and histopathological data revealed that the immortelle essential oil-based hydrogel significantly improves wound repair. Superior re-epithelialization, scar maturation, and increased collagen fiber density were achieved after immortelle essential oil-based gel application. Conclusions: These findings suggest that the immortelle essential oil-based hydrogel could be a natural, safe, and effective wound-healing dressing. [ABSTRACT FROM AUTHOR]

A thermoresponsive molecularly imprinted hydrogel sensor was constructed for the specific selective recognition of enterovirus 71 (EV71). Due to the introduction of the thermosensitive monomer N-isopropylacrylamide (NIPAM), when the imprinted hydrogel is incubated with the virus at 37℃, the surface specific imprinting cavity will specifically recognize and capture the target virus EV71. When the temperature rises to 45℃, the combined EV71 is rapidly released due to changes in the shape and function of the imprinted sites. The MIP hydrogel-based viral sensor developed recognized, captured, and released the target virus in a non-invasive way. The imprinting factor of the target virus was 5.2, suggesting high selectivity, and the detection limit was 7.1 fM, suggesting high sensitivity. Detection was rapid, as adsorption equilibrium was achieved within 30 min. This method provides a new sustainable avenue for the simple and rapid detection of viruses. [ABSTRACT FROM AUTHOR]

This study investigates the removal efficiency of Cu2+ from wastewater using a composite hydrogel made of carbon nanotubes (CNTs), sodium alginate (SA), and polyacrylic acid (PAA) prepared by free radical polymerization. The CNTs@SA/PAA hydrogel's structure and properties were characterized using SEM, TEM, FTIR, XRD, rheology, DSC, EDS, elemental mapping analysis, and swelling. The adsorption performance for Cu2+ was tested in batch adsorption experiments, considering the pH, dosage, initial concentration, and contact time. The optimal conditions for Cu2+ removal were pH 5.0, an adsorbent dosage of 500 mg/L, and a contact time of 360 min. The adsorption followed pseudo-second order kinetics. Isotherm analyses (Langmuir, Freundlich, Temkin, Dubinin–Radushkevich, Sips, Toth, and Khan) revealed that the Freundlich isotherm best described the adsorption, with a maximum capacity of 358.52 mg/g. A thermodynamic analysis indicated that physical adsorption was the main interaction, with the spontaneity of the process also demonstrated. This study highlights the high efficiency and environmental friendliness of CNT@SA/PAA composites for Cu2+ removal from wastewater, offering a promising approach for water treatment. [ABSTRACT FROM AUTHOR]

This study reveals the pH-responsive behavior of collagen hydrogels prepared using ultraviolet (UV) irradiation with riboflavin as a photosensitizer. By varying the UV exposure time, we modulated the crosslinking density, thereby influencing the mechanical properties and pH responsiveness. Rheological analysis confirmed successful network formation, whereas swelling studies revealed significant pH-dependent behavior, with maximum swelling at a pH of four and minimal swelling above a pH of six, demonstrating partial reversibility over multiple pH cycles. Mechanical testing showed a pH-dependent elastic modulus, which increased 10 fold from a pH of 6 to 10. Fibroblast proliferation assays confirmed the biocompatibility of the hydrogels, with cell growth positively correlating with the UV exposure time. This research demonstrates the potential of UV-crosslinked collagen hydrogels in biomedical applications, such as tissue engineering and drug delivery, where pH responsiveness is essential. [ABSTRACT FROM AUTHOR]

Hydrogels have emerged as promising candidates for biomedical applications, especially in the treatment of skin wounds, as a result of their unique structural properties, highly tunable physicochemical properties, and excellent biocompatibility. The integration of smart-response features into hydrogels allows for dynamic responses to different external or internal stimuli. Therefore, this paper reviews the design of different smart-responsive hydrogels for different microenvironments in the field of skin wound therapy. First, the unique microenvironments of three typical chronic difficult-to-heal wounds and the key mechanisms affecting wound healing therapeutic measures are outlined. Strategies for the construction of internal stimulus-responsive hydrogels (e.g., pH, ROS, enzymes, and glucose) and external stimulus-responsive hydrogels (e.g., temperature, light, electricity, and magnetic fields) are highlighted from the perspective of the wound microenvironment and the in vitro environment, and the constitutive relationships between material design, intelligent response, and wound healing are revealed. Finally, this paper discusses the severe challenges faced by smart-responsive hydrogels during skin wound repair and provides an outlook on the combination of smart-responsive hydrogels and artificial intelligence to give scientific direction for creating and using hydrogel dressings that respond to stimuli in the clinic. [ABSTRACT FROM AUTHOR]

The development of physically crosslinked hydrogels with excellent mechanical and sensing properties is of importance for expanding the practical applications of intelligent soft hydrogel materials. Herein, after copolymerization of hydroxyl-containing amino acid derivative N-acryloyl serine (ASer) with acrylamide (AM), we introduce Zr4+ through an immersion strategy to construct metal ion-toughened non-covalent crosslinked hydrogels (with tensile strength of up to 5.73 MPa). It is found that the synergistic coordination of hydroxyl and carboxyl groups with Zr4+ substantially increases the crosslinking density of the hydrogels, thereby imparting markedly superior mechanical properties compared to hydroxyl-free Zr4+-crosslinked hydrogels, such as N-acryloyl alanine (AAla) copolymerized with AM hydrogels (with tensile strength of 2.98 MPa). Through the adjustment of the composition of the copolymer and the density of coordination bonds, the mechanical properties of the hydrogels can be modulated over a wide range. Additionally, due to the introduction of metal ions and the dynamic nature of coordination bonds, the hydrogels also exhibit excellent sensing performance and good self-recovery properties, paving the way for the development of flexible electronic substrates with outstanding comprehensive performances. [ABSTRACT FROM AUTHOR]

Development of artificial dental pulp for the regeneration of pulpectomized root canal is of vital importance in maintaining the tooth's health and function. To achieve this objective, designing a pulp-like structure able to support tissue repair and vascularization is needed. In the current study, we developed a composite hydrogel based on collagen hydrogel and resveratrol-loaded chitosan nanoparticles. Various physicochemical and biological properties of the hydrogel system were investigated in vitro. The healing potential of the artificial pulp was studied in a rabbit model of dental pulp injury. Study revealed the composite hydrogel had significantly higher healing activity compared with simple hydrogel, as evidenced by the results of histopathological examinations. Real-time PCR assay showed that the composite hydrogel system could enhance the level of VEGF expression and modulated inflammation via decreasing NFKβ expression. [ABSTRACT FROM AUTHOR]

A portable sensing platform with excellent performance was constructed using CoNi-MOF-based chitosan-polyacrylamide hydrogel as a signal amplifier for the detection of adrenaline. [Display omitted] The development of a portable smartphone-based electrochemical sensor for analyzing adrenaline levels in real samples can make a great contribution to the research community worldwide. In order to achieve this goal, the key challenge is to build sensing interfaces with excellent electrocatalytic properties. In this work, microspherical bimetallic metal–organic frameworks (CoNi-MOF) consisting of nanoclusters were first synthesized using a hydrothermal method. On this basis, the catalytic activity of pure chitosan-polyacrylamide hydrogel (CS-PAM) was modulated by adding different amounts of CoNi-MOF during the in-situ synthesis of CS-PAM. Finally, a portable electrochemical detection system based on CS-PAM was established for the detection of adrenaline. A series of resulting composite hydrogels with a large specific surface area, abundant active sites, and unique network structure facilitate the enrichment and catalysis of adrenaline molecules. Under optimal conditions, the analytical platform constructed by using CoNi-MOF-based CS-PAM has the advantages of a wide detection range (0.5–10 and 10–2500 μM), a low detection limit (0.167 μM), and high sensitivity (0.182 and 0.133 μA·μM·cm−2). In addition, the sensor maintains selective detection of the target in the presence of many different types of interferences, and the current response is not significantly reduced even after 60 cycles of testing. We strongly believe that the designed smart portable sensing can realize the accurate determination of adrenaline in complex systems, and this study can provide new ideas for the research of MOFs-based hydrogels in electrochemical analysis. [ABSTRACT FROM AUTHOR]

In the graphical abstract, we illustrate the innovative design of physical–chemical hybrid crosslinked composite hydrogels that exhibit a unique combination of properties, making them well-suited for advanced applications in flexible electronics and biosensing. These hydrogels demonstrate ideal stretchability and compressibility, alongside excellent adhesion capabilities. Their design is strategically tailored to ensure biocompatibility without compromising the sensitive detection of physiological signals. The graphical representation showcases the multifaceted nature of these materials, highlighting their dynamic responsiveness to mechanical stimuli and their potential to seamlessly interface with biological tissues for real-time monitoring and diagnostic purposes. [Display omitted] With the advancement of wearable and implantable medical devices, hydrogel flexible bioelectronic devices have attracted significant interest due to exhibiting tissue-like mechanical compliance, biocompatibility, and low electrical resistance. In this study, the development and comprehensive performance evaluation of poly(acrylic acid)/ N,N′-bis(acryloyl) cystamine/ 1-butyl-3-ethenylimidazol-1-ium:bromide (PAA/NB/IL) hydrogels designed for flexible sensor applications are introduced. Engineered through a combination of physical and chemical cross-linking strategies, these hydrogels exhibit strong mechanical properties, high biocompatibility, and effective sensing capabilities. At 95 % strain, the compressive modulus of PAA/NB/IL 100 reach up to 3.66 MPa, with the loading–unloading process showing no significant hysteresis loop, indicating strong mechanical stability and elasticity. An increase in the IL content was observed to enlarge the porosity of the hydrogels, thereby influencing their swelling behavior and sensing functionality. Biocompatibility assessments revealed that the hemolysis rate was below 5 %, ensuring their suitability for biomedical applications. Upon implantation in rats, a minimal acute inflammatory response was observed, comparable to that of the biocompatibility control poly(ethylene glycol) diacrylate (PEGDA). These results suggest that PAA/NB/IL hydrogels hold promise as biomaterials for biosensors, offering a balance of mechanical integrity, physiological compatibility, and sensing sensitivity, thereby facilitating advanced healthcare monitoring solutions. [ABSTRACT FROM AUTHOR]

Hydrogels have revolutionized the field of soft robotics with their ability to provide dynamic and programmable responses to different stimuli, enabling the fabrication of highly adaptable and flexible robots. This continual development holds significant promise for applications in biomedical devices, active implants, and sensors due to the biocompatibility of hydrogels. Actuation in hydrogel-based soft robotics relies on variations in material properties, structural design, or a combination of both to generate desired movements and behaviors. While such traditional approaches enable hydrogel actuation, they often rely on complex material design, bringing challenges to hydrogel fabrication and hindering practical use. Therefore, this work seeks to present a simplified and versatile approach for fabricating programmable single-component hydrogel-based soft robotics using an encoded building block design concept and 3D printing. A series of structural building blocks have been designed to achieve various actuation characteristics, including the direction, degree, and kinetics of actuation. By assembling these building blocks into various configurations, a broader range of actuation responses can be encoded, allowing for the fabrication of versatile, programmable soft robotics using a single uniform material through vat photopolymerization 3D printing. This approach enables adaptation to a wide range of applications, providing highly customizable encoding designs. [ABSTRACT FROM AUTHOR]

Conductive polymer hydrogels (CPHs) are gaining considerable attention in developing wearable electronics due to their unique combination of high conductivity and softness. However, in the absence of interactions, the incompatibility between hydrophobic conductive polymers (CPs) and hydrophilic polymer networks gives rise to inadequate bonding between CPs and hydrogel matrices, thereby significantly impairing the mechanical and electrical properties of CPHs and constraining their utility in wearable electronic sensors. Therefore, to endow CPHs with good performance, it is necessary to ensure a stable and robust combination between the hydrogel network and CPs. Encouragingly, recent research has demonstrated that incorporating supramolecular interactions into CPHs enhances the polymer network interaction, improving overall CPH performance. However, a comprehensive review focusing on supramolecular CPH (SCPH) for wearable sensing applications is currently lacking. This review provides a summary of the typical supramolecular strategies employed in the development of high‐performance CPHs and elucidates the properties of SCPHs that are closely associated with wearable sensors. Moreover, the review discusses the fabrication methods and classification of SCPH sensors, while also exploring the latest application scenarios for SCPH wearable sensors. Finally, it discusses the challenges of SCPH sensors and offers suggestions for future advancements. [ABSTRACT FROM AUTHOR]

Knee cartilage has limited natural healing capacity, complicating the development of effective treatment plans. Current non-cell-based therapies (e.g., microfracture) result in poor repair cartilage mechanical properties, low durability, and suboptimal tissue integration. Advanced treatments, such as autologous chondrocyte implantation, face challenges including cell leakage and inhomogeneous distribution. Successful cell therapy relies on prolonged retention of therapeutic biologicals at the implantation site, yet the optimal integration of implanted material into the surrounding healthy tissue remains an unmet need. This study evaluated the effectiveness of a newly developed photo-curable adhesive hydrogel for cartilage repair, focusing on adhesion properties, integration performance, and ability to support tissue regeneration. The proposed hydrogel design exhibited significant adhesion strength, outperforming commercial adhesives such as fibrin-based glues. An in vivo goat model was used to evaluate the hydrogels' adhesion properties and long-term integration into full-thickness cartilage defects over six months. Results showed that cell-free hydrogel-treated defects achieved superior integration with surrounding tissue and enhanced cartilage repair, with notable lateral integration. In vitro results further demonstrated high cell viability, robust matrix production, and successful cell encapsulation within the hydrogel matrix. These findings highlight the potential of adhesive hydrogel formulations to improve the efficacy of cell-based therapies, offering a potentially superior treatment for knee cartilage defects. [ABSTRACT FROM AUTHOR]

The Rhipicephalus microplus tick causes enormous economic losses in livestock farming around the world. Despite several promising studies carried out with plant extracts such as Achyrocline satureioides against this ectoparasite, a major obstacle is related to pharmaceutical presentation forms. There is no study showing xantan gum-based hydrogel and polycaprolactone nanoparticles containing A. satureioides extract against R. microplus larvae. The objective of this study was to incorporate A. satureioides extract to develop a nanoformulation (AScn) and a hydrogel (ASlh) and evaluate them against R. microplus larvae with the purpose of increasing the contact time of the extract with the larvae and improve the effectiveness. The ethanolic extracts were incorporated in polycaprolactone nanoparticles and characterized via analysis of the mean hydrodinamic diameter and polidispersity index. The xanthan gum-based hydrogel formulation was prepared with crude extract of A. satureioides 40 mg/mL, 0.25% xanthan gum, and 8% poloxamer, to determine the bioadhesiveness of the formulation in bovine leather and the flow rate of the formulation in the animal. The results in larvae demonstrated that when evaluated in the form of a hydrogel (ASlh), mortality was higher, with 91.48% mortality at a concentration of 20 mg/mL presenting itself as an interesting alternative for controlling this ectoparasite. [ABSTRACT FROM AUTHOR]

In this work, the effect of incorporating silk fibroin, a fibrous biocompatible protein, into physically cross-linked agarose hydrogels was investigated as a simple model study to examine how supramolecular fibrous structures influence the properties of the hydrogels. The rheological and transport properties were studied. Fibroin did not change the general viscoelastic properties of the investigated hydrogels but changed the viscoelastic moduli values and also the mesh size, as calculated from rheometry data. Fibroin influenced the mechanical properties depending on its concentration: at lower concentrations, it increased the mesh size, while at higher concentrations, it acted as a filler, decreasing the mesh size. Similarly, the storage and loss moduli were affected, either increasing or decreasing based on the fibroin concentration. The fibroin effect on the diffusion of two dyes differing in their charge was the result of a combination of structural effects, responsible also for changes in the rheological properties, and a result of electrostatic interactions between the charged groups. For positively charged methylene blue, low fibroin concentrations accelerated diffusion, while higher concentrations slowed it by filling network vacancies. In contrast, for negatively charged eosin-B, fibroin strongly impeded diffusion at all concentrations due to electrostatic repulsion, leading to its accumulation at the hydrogel interface. The findings of this work may contribute to an understanding of the behavior of the extracellular matrix or soft tissues as well as to the development of the tailored design of hydrogel materials. [ABSTRACT FROM AUTHOR]

In recent years, natural substance‐based tissue adhesive hydrogels have been widely studied by researchers because of their practicability and affordability. In this review, we summarized the design principles and mechanisms for constructing natural substance‐based tissue adhesive hydrogels from the perspective of polyphenols (catechol, dopamine, tannic acid), cationic polymers (chitosan, lysine, cationic antibacterial peptides), polysaccharides and other natural substances. In addition, according to the morphology and size of tissue adhesive hydrogels, it was divided into macroscopic hydrogels and microscopic hydrogels. Therefore, the natural substance‐based adhesive macroscopic hydrogels such as injectable hydrogels and hydrogel patches and natural substance‐based adhesive microscopic hydrogels including hydrogel microspheres were reviewed. Furthermore, we summarized the review and provided outlook based on the present tissue adhesive hydrogels. The review aimed to summarize the progress in natural substance‐based tissue adhesive hydrogels and provide a valuable reference for the development of tissue adhesive hydrogels and its applications in biomedical field. [ABSTRACT FROM AUTHOR]

This research focuses on the formulation and evaluation of a hydrogel derived from Saraca indica bark for antimicrobial treatment. The study involved the extraction of phytochemicals from plant leaves using a Soxhlet apparatus with ethanol, methanol and water as solvents. Hydrogel formulations (F1, F2, F3) were prepared using different gelling agents (Carbopol 934, Carbopol 940 and HPMC) and were characterized for physical properties, pH, viscosity and antimicrobial activity. The hydrogel's homogeneity, spreadability and drug content were assessed, along with in vitro drug release using Franz diffusion cells to simulate drug absorption. The results showed that the hydrogels exhibited consistent physical properties, with no phase separation, and a pH range between 5.4 and 6.1, making them suitable for topical application. The evaluation demonstrated effective formulation procedures and promising results for Saraca indica-based hydrogel as a potential antimicrobial treatment. [ABSTRACT FROM AUTHOR]

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[Display omitted] • Cellulose-based photoresponsive hydrogels were synthesized by hydrothermal method. • The hydrogel exhibited fluorescence switching with ethanol selective response. • Information encryption/decryption function of the hydrogel was realized. • Photochromic/fluorescent switching was applied in anti-counterfeiting applications. The rapid development of anti-counterfeiting technology has brought new challenges to the repeatability and stability of reversible fluorescence/photochromic switching hydrogels. To address this issue, a series of chemical cross-linked cellulose-based intelligent responsive hydrogels were synthesized by free-radical graft copolymerization in a hydrothermal process. This strategy allows for the creation of a chemical cross-linked three-dimensional structure that anchors photochromic ammonium molybdate and fluorescent carbon dots together, resulting in enhanced stability and mechanical properties. Especially, the tensile and compressive strength of hydrogel reached a maximum value of 280 kPa and 560 kPa, respectively, which far exceeds that of some reported hydrogels. The resultant hydrogels exhibited desired reversible fluorescence/photochromic switching, reversible printing and erasing of patterns, and information encryption/decryption. Notably, the change of photochromism from yellow to green can be realized, and the self-fading process can be shortened to 25 min at 60 °C instead of 6 h at room temperature. More importantly, the fluorescence quenching phenomenon of the hydrogel occurs gradually after 2 min of continuous irradiation, and it can be recovered by selective treatment with ethanol. Overall, this study provides a simple strategy for the preparation of environmentally friendly reversible fluorescence/photochromic switching cellulose-based hydrogels for information encryption. [ABSTRACT FROM AUTHOR]

The biocompatible CS-PpIX-PDA hydrogel dressing is constructed by the incorporation of photosensitizer protoporphyrin (PpIX) and photothermal polydopamine (PDA) into CS. The hydrogel exhibits a remarkable ability of bacteria-trapping when coated on the wound site. Under the excitation of 660/808 nm, the combined photothermal and photodynamic effects can effectively eradicate bacteria. Simultaneously, the hydrogel also demonstrates anti-inflammatory properties and upregulates HSP90 expression, thereby promoting collagen deposition and facilitating wound healing. [Display omitted] Phototherapy has emerged as a potential treatment strategy for bacteria-infected wounds, but the inadequate bacteria-capturing ability and excessive damage to normal tissues from single phototherapy are huge limitations. To solve the issues, herein we report the design of chitosan-based hydrogel with bacteria capturing and combined photothermal/photodynamic sterilization functions. Such hydrogel is prepared by mixing chitosan (CS) as matrix, protoporphyrin (PpIX) as photosensitizer and polydopamine (PDA) as photothermal agent and then chemically cross-linking CS with glutaraldehyde. The resulting CS-PpIX-PDA hydrogel possesses a porous architecture (average pore porosity = 60.9 %), excellent swelling capabilities (swelling ratio = 1855 %) and rheological property (G′ > G″). The hydrogel can effectively produce reactive oxygen species (ROS) under 660 nm light irradiation due to the photodynamic effect of PpIX. Owing to the presence of PDA, the hydrogel displays a photoabsorption range between 600 and 1500 nm and can generate maximal temperature of 60 °C within 10 min under 808 nm laser illumination (0.6 W/cm2) through photothermal effect. Besides, under synergetic illumination of 808/660 nm laser, CS-PpIX-PDA hydrogel can induce the death of 99.9999 % of E. coli and 99.99999 % of S. aureus. Importantly, when coated on the wound site, the hydrogel exhibits a remarkable bacteria-trapping ability due to its porous structure and the presence of amino groups on chitosan. Under the excitation of 660/808 nm, the combined photothermal and photodynamic effects can effectively eradicate bacteria. Simultaneously, the hydrogel also demonstrates anti-inflammatory properties and upregulates Heat Shock Protein 90 (HSP90) expression, thereby promoting collagen deposition and facilitating wound healing. Therefore, the study may provide some new insights into the development of multifunctional hydrogel for photothermal-oxidation sterilization of bacteria-infected wound therapy. [ABSTRACT FROM AUTHOR]

Intelligent materials are used to create novel biomaterials that can recognize and respond to environmental cues, as well as perform specific tasks for modern medicine and sustainability. There are a wide range of applications for intelligent biomaterials, from ecological restoration to health. In reaction to physical, chemical, and biological stimuli, intelligent biomaterials can change their properties. Hydrogels have garnered a lot of attention and the incorporation of decellularized tissues into the hydrogel synthesis process exhibits a number of benefits. The development of smart/intelligent response polymeric biomaterials for novel biomedical applications is the focus of this review. [ABSTRACT FROM AUTHOR]

The creation of functional hydrogels with robust load‐bearing capacity adaptable to complex tissue regeneration remains challenging. Silk fibroin (SF) is a natural biomaterial with excellent mechanical strength and cell adhesion capacity, possessing tremendous potential to solve the aforementioned dilemma. The excellent biodegradability and biocompatibility and the molecular structure with multiple modifiable moieties provide opportunities for the injectability and multifunctionality of hydrogels. Furthermore, the incorporation of other polymers or active ingredients can improve the basic properties, confer biological activities and pharmacological effects, and provide the prerequisites for hydrogels to fulfill specific requirements. Therefore, SF‐based hydrogels are widely applied in tissue repair and regeneration, especially in bone, skin, nerve, liver, myocardium, and cornea, which have effectively addressed the challenges of scaffolds' lack of cell adhesion sites, excessive degradation, as well as the lack of efficient, long‐lasting antimicrobial properties. This review outlines the properties of SF, discusses the types of materials commonly used in the preparation of hydrogels and their characteristics, and describes the current construction methods of SF hydrogels. Simultaneously, recent advancements in applying SF‐based multifunctional hydrogels within biological tissues are explored, with a focus on their role in tissue repair, highlighting the repair mechanism of SF based on bone and skin. [ABSTRACT FROM AUTHOR]

Herein, a novel hydrogel (HG-cl-poly(AA)) was synthesized by grafting acrylic acid (AA) onto Hing gum (HG) using methylene-bis-acrylamide (MBA) as a cross-linker and ammonium persulfate (APS) as an initiator in a hot air oven. The percentage swelling of the hydrogel was examined by optimizing various reaction parameters to ensure its maximum swelling percentage. The formation of crosslinked networks was confirmed using Fourier-Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) techniques. The surface area and hydrophilicity of the prepared hydrogel were determined using Brunauer–Emmett–Teller analyzer and wettability studies, demonstrating a clear correlation with adsorption. The adsorption of crystal violet (CV) dye on the prepared hydrogel was studied via a batch adsorption system based on the amount of adsorbent, immersion time, pH level, and initial dye concentration. The prepared hydrogel showed a 99% removal rate and an excellent adsorption capacity of 492.61mg/g due to the electrostatic, H-bonding, and dipole–dipole interactions between the adsorbent surface and dye molecules. The results were further analyzed using the Langmuir, Freundlich, and Tempkin isotherm models. The study suggests consistency with the pseudo-second-order kinetic model (R2=0.998), further supported by the best data fit with the Langmuir isotherm model (R2=0.991). The thermodynamic study results indicated that the adsorption process is endothermic and spontaneous. Regeneration (desorption) studies showed that the prepared hydrogel could remove CV dye from an aqueous solution and maintain the highest adsorption capacity even after multiple adsorption and desorption cycles. Therefore, the prepared HG-cl-poly(AA) hydrogel could be a potential adsorbent for dye removal and have an admirable capacity for cleaning the aquatic environment. [ABSTRACT FROM AUTHOR]

This review provided a comprehensive overview in four types of strain sensors, including piezoelectric, resistive, triboelectric, and capacitive strain sensors, and their sensing mechanisms were summarized. The essential methods for improving the sensitivity of hydrogel strain sensors were discussed, which involved the selection of suitable materials such as conductive nanoparticles and ionic materials and the adoption of specific structural designs such as microspheres, sawtooth-like patterns, and porous structures. A comprehensive integration of these factors was also involved. These strategies enable the hydrogel strain sensors to obtain a high sensitivity. Furthermore, the application of hydrogel strain sensors in the fields of smart electronics, wearable devices, and medical health were introduced. Finally, the current challenges and the prospect of future opportunities in the development and applications of hydrogel strain sensors were discussed. [ABSTRACT FROM AUTHOR]

Lateral Flow Assays (LFAs) are cost‐effective and widely utilized for rapid diagnostics, yet they often suffer from limited sensitivity. This study introduces a straightforward yet highly effective method to enhance LFAs performance by integrating a poly(ethylene glycol) diacrylate (PEGDA) hydrogel to create a "reaction trap." This hydrogel reaction trap optimizes the flow rate and reaction time at the sensing components, substantially improving assay performance. By applying various hydrogel concentrations (6%, 9%, 12%, 15%, and 18% w/v), significant enhancements across a range of detection systems are achieved. An optimized 18% hydrogel concentration shows a 1.5 times increase in sensitivity in the tested commercial pregnancy test. Additionally, 12% hydrogel concentration is tested in pregnancy, ovulation, and Coronavirus disease 2019 (COVID‐19) commercial kits, and the improvement reached up to a sevenfold increase in signal intensity. The enhancement in detection illustrates the profound impact of this simple modification and shows the importance of hydrogel concentration optimization to maximize detection improvement. These results demonstrate that hydrogel‐coated LFAs offer a scalable and highly effective solution for boosting the reliability and sensitivity of rapid diagnostics across different healthcare settings, with broad potential for global health diagnostics applications. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (Au NPs) are unique catalysts due to their increased coordination unsaturation via nanoparticulation. Effective functioning requires an appropriate support to maintain particle dispersion without compromising nanoscale properties. Cross‐linked hydrophilic polymer‐derived hydrogels are ideal supports, particularly for biological and biomedical reactions, due to their aqueous affinity and biocompatibility. However, applications in confined spaces, such as in vivo environments, necessitate hydrogel micronization. This study introduces microsized DNA hydrogels as support for Au catalysts. DNA motif‐composed hydrogel particles exhibit high crosslinking density and produce small Au NPs owing to short DNA strands. This system significantly enhances catalytic efficiency compared to similar‐sized Au NP gel‐supported catalysts and requires minimal gold catalyst. Modulating DNA hydrogel crosslinking density allows easy control of Au NP size and catalytic activity, further improved by increased hydrogel surface area through microparticulation. These findings demonstrate DNA nanotechnology's versatility in tailoring DNA hydrogel properties and Au NP catalytic behavior. Computer‐aided design enables precise particle property and motif arrangement manipulation, offering promising customizable catalytic systems. [ABSTRACT FROM AUTHOR]

Hydrogels present attractive opportunities as flexible sensors due to their soft nature and tunable physicochemical properties. Despite significant advances, practical application of hydrogel‐based sensor is limited by the lack of general routes to fabricate materials with combination of mechanical, conductive, and biological properties. Here, a multi‐functional hydrogel sensor is reported by in situ polymerizing of acrylamide (AM) with N,N′‐bis(acryloyl)cystamine (BA) dynamic crosslinked silver‐modified polydopamine (PDA) nanoparticles, namely PAM/BA‐Ag@PDA. Compared with traditional polyacrylamide (PAM) hydrogel, the BA‐Ag@PDA nanoparticles provide both high‐functionality crosslinks and multiple interactions within PAM networks, thereby endowing the optimized PAM/BA‐Ag@PDA hydrogel with significantly enhanced tensile/compressive strength (349.80 kPa at 383.57% tensile strain, 263.08 kPa at 90% compressive strain), lower hysteresis (5.2%), improved conductivity (2.51 S m−1) and excellent near‐infrared (NIR) light‐triggered self‐healing ability. As a strain sensor, the PAM/BA‐Ag@PDA hydrogel shows a good sensitivity (gauge factor of 1.86), rapid response time (138 ms), and high stability. Owing to abundant reactive groups in PDA, the PAM/BA‐Ag@PDA hydrogel exhibits inherent tissue adhesiveness and antioxidant, along with a synergistic antibacterial effect by PDA and Ag. Toward practical applications, the PAM/BA‐Ag@PDA hydrogel can conformally adhere to skin and monitor subtle activities and large‐scale movements with excellent reliability, demonstrating its promising applications as wearable sensors for healthcare. [ABSTRACT FROM AUTHOR]

Cartilage repair remains a major challenge in human orthopedic medicine, necessitating the application of innovative strategies to overcome existing technical and clinical limitations. Adhesive hydrogels have emerged as promising candidates for cartilage repair promotion and tissue engineering, offering key advantages such as enhanced tissue integration and therapeutic potential. This comprehensive review navigates the landscape of adhesive hydrogels in cartilage repair, discussing identified challenges, shortcomings of current treatment options, and unique advantages of adhesive hydrogel products and scaffolds. While emphasizing the critical need for in situ lateral integration with surrounding tissues, we dissect current limitations and outline future perspectives for hydrogel scaffolds in cartilage repair. Moreover, we examine the clinical translation pathway and regulatory considerations specific to adhesive hydrogels. Overall, this review synthesizes the existing insights and knowledge gaps and highlights directions for future research regarding adhesive hydrogel-based devices in advancing cartilage tissue engineering. [ABSTRACT FROM AUTHOR]