Natural hydrogel dressings in wound care: Design, advances, and perspectives

Porcine plasma protein cold-set hydrogel crosslinked by genipin and the immunomodulatory, proliferation promoting and scar-remodeling in wound healing

Addressing the critical need for biocompatible and multifunctional wound dressings for chronic and non-healing wounds, cold-set hydrogel using natural biomacromolecules are potential candidates. This study developed a novel cold-set hydrogel of porcine plasma protein (PPP) through genipin (GP) as crosslinker and glucono delta-lactone (GDL) as acidifier. GP promoted hardness, springiness, water holding capacity (WHC) and modulus in a dose-dependent manner in the presence of GDL, and significantly enhanced microstructural density, integrity and anti-degradation, critical as wound dressing, achieving the optimal performance at 0.15 % GP and 0.2 % GDL. Subsequently, biocompatibility assessments revealed that the optimum PPP gel was low cytotoxicity and could support cell migration and proliferation, reduce apoptosis with dose-effect relationship of the filler PPP. Meanwhile, in vivo skin wound healing model indicated the efficacy in accelerating wound healing, reducing inflammation, and promoting tissue remodeling without excessive scar formation. These effects are attributed to the ability of PPP in the hydrogel to modulate local inflammatory responses, enhance angiogenesis, and balance extracellular matrix remodeling processes. In conclusion, this pioneering work establishes PPP cold-set hydrogels as promising candidates for advanced wound care solutions, combining the benefits of natural protein-based biomaterials with innovative crosslinking strategies to meet urgent clinical needs in regenerative medicine.

A sustained H2S-releasing nanocellulose-based hydrogel with anti-inflammatory and antibacterial properties for promoting infected wound healing

Infected wounds present unique challenges during healing, often characterized by prolonged inflammation and delayed tissue recovery. To address these issues, we developed a composite hydrogel (CAEG), which integrated a hydrogen sulfide (H2S) donor (GYY4137), carboxylated nanocellulose (CNF-C) and ε-polylysine (ε-PL). This hydrogel was designed to enhance wound healing by mitigating inflammation and preventing infections. In vitro studies demonstrated that CAEG hydrogel facilitated cell migration, angiogenesis, and macrophage polarization toward the M2 anti-inflammatory phenotype through controlled H2S release. The ε-PL component provided additional antibacterial effects via electrostatic interactions. In vivo experiments confirmed that the CAEG hydrogel effectively accelerated wound closure in full-thickness skin infected wounds. These findings highlighted the CAEG hydrogel's potential as a promising tool for treating infected wounds by leveraging its dual anti-inflammatory and antibacterial capabilities.

Silver Ion-Triggered Fabrication of AuAg Bimetallic Aerogel Superstructures with Tailored Antibacterial Property for Advanced Anti-Infection Management

The clinical application of antibiotic-free, Ag-based antibacterial agents remains a significant challenge due to uncontrolled Ag+-release and limited long-term antibacterial activity. Herein, a robust antibacterial platform based on Ag+-triggered self-assembled AuAg aerogel is developed for advanced infectious wound management. By employing ultrasmall-sized gold nanoclusters (AuNCs) as building blocks, Ag+ serves as the gelator to actively interact with AuNCs through multiple types of interactions, including coordination, metallophilic interactions, and the Anti-Galvanic Reduction reaction. As a result, novel 3D self-supported porous AuAg bimetallic aerogels can be controllably fabricated. The obtained AuAg aerogels exhibit tunable ligament size in the range of 8.5-32.0 nm, adjustable composition, and controllable antibacterial properties. Mechanistic studies reveal that the initial concentration of Ag+ plays a critical role in determining the nanostructure and composition of AuAg aerogels as well as their antibacterial efficacy. A higher concentration of Ag+ enables a more stable and sustainable release of Ag+ from AuAg aerogels, leading to long-term and on-demand anti-infection effects. Consequently, these AuAg aerogels display significant anti-infection, anti-inflammation, and pro-regenerative effects for the treatment of infectious wounds, as demonstrated by the in vivo studies. This work provides a new approach for reasonable design and flexible manipulation of metal aerogels for versatile biomedical applications.

Bacterial microenvironment-responsive antibacterial, adhesive, and injectable oxidized dextran-based hydrogel for chronic diabetic wound healing

Diabetic wounds are highly susceptible to bacterial infections, often resulting in chronic wounds that pose a substantial challenge to clinical treatment. Furthermore, the irregular shapes of these wounds limit the effectiveness of conventional dressings. Therefore, development of a new type of antibacterial dressing that can accommodate various wound shapes is urgently required. In this study, we designed injectable hydrogels with bacterial microenvironment-responsive antibacterial, adhesive, and antioxidant properties. These hydrogels were developed by incorporating polydopamine nanoparticles (PDA NPs) into a gelatin/oxidized dextran (Gel-oDex) network crosslinked via dynamic Schiff base reactions. Notably, the Gel-oDex-PDA-PHMB hydrogel demonstrated strong antibacterial efficacy against S. aureus, E. coli, and MRSA (all exceeding 99%), with PHMB-release experiments confirming its responsiveness to the bacterial microenvironment. Additionally, the hydrogel exhibited significant antioxidant activity, as evidenced by the DPPH radical scavenging assays. With good biocompatibility, the Gel-oDex-PDA-PHMB hydrogel also demonstrated effectiveness in killing bacteria and promoting the regeneration and functional reconstruction of skin tissue in bacteria-infected diabetic rats.

An Antibacterial Hydrogel Based on Silk Sericin Cross-Linking Glycyrrhizic Acid and Silver for Infectious Wound Healing

Bioactive hydrogels are garnering increasing interest in wound management due to their porous structural features and versatile intrinsic biological activities. Importantly, the antibacterial capacity is a crucial requirement for hydrogel dressings in chronically infected wounds. In this study, we report an antibacterial hydrogel constructed from silk sericin (SS) cross-linked with glycyrrhizic acid (GA) and integrated with silver ions (Ag+) to accelerate the healing of bacterial-infected wounds. The resultant sericin-glycyrrhizic acid-Ag+ hydrogel (SGA) demonstrates favorable mechanical properties, effectively preventing secondary injury to wounds. Moreover, in vitro studies indicated that the SGA hydrogel possesses excellent swelling ratios, degradability, and cytocompatibility, promoting cell growth and proliferation. Notably, the SGA hydrogel exhibited effective antibacterial activity against both Gram-positive and Gram-negative bacteria through the release of Ag+. In a Staphylococcus aureus-infected wound model, the SGA hydrogel efficiently eradicated bacteria, thus promoting wound repair. Overall, our work establishes a novel strategy for developing multifunctional hydrogel dressings based on natural materials for managing bacteria-infected wounds.

Polymer Applied in Hydrogel Wound Dressing for Wound Healing: Modification/Functionalization Method and Design Strategies

Hydrogel wound dressings have emerged as a promising solution for wound healing due to their excellent mechanical and biochemical properties. Over recent years, there has been significant progress in expanding the variety of raw materials used for hydrogel formulation along with the development of advanced modification techniques and design approaches that enhance their performance. However, a comprehensive review encompassing diverse polymer modification strategies and design innovations for hydrogel dressings is still lacking in the literature. This review summarizes the use of natural polymers (e.g., chitosan, gelatin, sodium alginate, hyaluronic acid, and dextran) and synthetic polymers (e.g., poly(vinyl alcohol), polyethylene glycol, Pluronic F-127, poly(N-isopropylacrylamide), polyacrylamide, and polypeptides) in hydrogel wound dressings. We further explore the advantages and limitations of these polymers and discuss various modification strategies, including cationic modification, oxidative modification, double-bond modification, catechol modification, etc. The review also addresses design principles and synthesis methods, aligning polymer modifications with specific requirements in wound healing. Finally, we discuss future challenges and opportunities in the development of advanced hydrogel-based wound dressings.

DNA-based hydrogels for bone regeneration: A promising tool for bone organoids

DNA-based hydrogels stand out for bone regeneration due to their exceptional biocompatibility and programmability. These hydrogels facilitate the formation of spatial bone structures through bulk hydrogel fabricating, microsphere formatting, and 3D printing. Furthermore, the bone microenvironment can be finely tuned by leveraging the degradation products, nanostructure, targeting, and delivery capabilities inherent to DNA-based materials. In this review, we underscore the advantages of DNA-based hydrogels, detailing their composition, gelation techniques, and structure optimization. We then delineate three critical elements in the promotion of bone regeneration using DNA-based hydrogels: (i) osteogenesis driven by phosphate ions, plasmids, and oligodeoxynucleotides (ODNs) that enhance mineralization and promote gene and protein expression; (ii) vascularization facilitated by tetrahedral DNA nanostructures (TDNs) and aptamers, which boosts gene expression and targeted release; (iii) immunomodulation achieved through loaded factors, TDNs, and bound ions that stimulate macrophage polarization and exhibit antibacterial properties. With these advantages and properties, these DNA-based hydrogels can be used to construct bone organoids, providing an innovative tool for disease modeling and therapeutic applications in bone tissue engineering. Finally, we discuss the current challenges and future prospects, emphasizing the potential impacts and applications in regenerative medicine.

Development of hyaluronic acid-based hydrogels for chronic diabetic wound healing: A review

This research delves into the advancements in chronic skin wound treatment, with a particular focus on diabetic foot ulcers, utilizing hyaluronic acid (HA)-based hydrogels. Hyaluronic acid, an integral component of the skin's extracellular matrix, plays a crucial role in process such as inflammation, angiogenesis, and tissue regeneration. Due to their three-dimensional network structure, biocompatibility, hydrophilicity, and gas exchange capabilities, HA-based hydrogels are considered highly suitable for promoting wound healing. Nonetheless, pure HA hydrogels exhibit limitations including insufficient mechanical strength and rapid release of encapsulated substances. To address these limitations, the incorporation of bioactive materials such as chitosan and collagen was investigated. This combination not only optimized mechanical strength and degradation rates but also enhanced antibacterial and anti-inflammatory properties. Furthermore, responsive hydrogel dressings were developed to adapt to the specific characteristics of the diabetic wound microenvironment, enabling on-demand drug release. These advancements present new perspectives for the treatment of diabetic foot ulcers.

Tuning Room-Temperature Injectability of Gelatin-Based Hydrogels via Introduction of Competitive Hydrogen Bonds

As a natural biomaterial with a superior comprehensive performance, gelatin has been widely explored in various biomedical and bioengineering applications. However, the ease of solidification of gelatin solutions at room temperature causes great inconvenience in specific application scenarios where injection is required. Here we addressed this problem by introduction of competitive hydrogen bond (CHB)-containing substances to gelatin to interfere with the original intergelatin hydrogen bonds. Four representative CHB materials, metformin, l-arginine, polyarginine, and polyurea, all showed remarkable efficiency in tuning the "sol-gel" phase transition temperature of gelatin in a concentration-dependent manner. Systematic rheological measurements indicated that the addition of CHB materials significantly improved the room-temperature injectability of gelatin. Compared to gelatin alone, CHB-containing gelatin bioinks showed improved printability and shape fidelity in 3D bioprinting.

Material Design, Fabrication Strategies, and the Development of Multifunctional Hydrogel Composites Dressings for Skin Wound Management

The skin is fragile, making it very vulnerable to damage and injury. Untreated skin wounds can pose a serious threat to human health. Three-dimensional polymer network hydrogels have broad application prospects in skin wound dressings due to their unique properties and structure. The therapeutic effect of traditional hydrogels is limited, while multifunctional composite hydrogels show greater potential. Multifunctional hydrogels can regulate wound moisture through formula adjustment. Moreover, hydrogels can be combined with bioactive ingredients to improve their performance in wound healing applications. Stimulus-responsive hydrogels can respond specifically to the wound environment and meet the needs of different wound healing stages. This review summarizes the material types, structure, properties, design considerations, and formulation strategies for multifunctional hydrogel composite dressings used in wound healing. We discuss various types of recently developed hydrogel dressings, highlights the importance of tailoring their physicochemical properties, and addresses potential challenges in preparing multifunctional hydrogel wound dressings.

Calcium-ion-driving assembly of polysaccharide deriving from Zizyphus jujuba to hemostatic hydrogel for treating diabetic wound

Due to good biocompatibility and biodegradable, natural polysaccharide-based hydrogels have received worldwide attentions, where polysaccharide polymers were usually chemically modified to meet the specific elastic requirements. However, it remained highly challenging to develop polysaccharide-based hydrogels with desired mechanical properties and biological functions devoid of any structural modifications. Herein, with the coordination of Ca2+ (15.0 mM), the jujuba polysaccharide (JPS, 1 %) was facilely fabricated to a hydrogel (JPS-gel) within 1 min at pH 10, where the residual proteins also played crucial roles on the assembly. The JPS-gel showed outstanding stability and mechanical properties, which were tunable by adjusting the content of Ca2+/JPS. The JPS-gel also revealed excellent biocompatibility, and could expedite the migration and proliferation of healing-related cells, angiogenesis and alleviate inflammation response. More interestingly, the JPS-gel had hemostatic capacity, where the hemostatic time and blood loss in liver incision model were 13 ± 3 s and 6.3 ± 1.6 mg after 120 s treatment with JPS-gel, respectively. All these superiorities endowed JPS-gel high performance healing in diabetic wounds (10 days). Specially, the expressions of inflammation-related genes were downregulated, but gene expressions associated with cell migration and proliferation, and angiogenesis were upregulated, thus uncovering the action mechanism of JPS-gel on accelerating wound contraction.

Synthesis of a retro-GFOGER Adamantane-Based Collagen Mimetic Peptide Imbibed in a Hyaluronic Acid Hydrogel for Enhanced Wound Healing

This study reported the synthesis and formulation of an adamantane-based collagen mimetic peptide (CMP) hydrogel containing the integrin-binding motif retro-GFOGER, designed to enable the controlled delivery of CMPs with the ability of direct wound healing for the potential treatment of acute wounds. Initially, two adamantane-functionalized CMPs (peptides NL008 and NL010) were synthesized, characterized, and comparatively screened for their in vitro biocompatibility and bioactivity. In vitro evaluations of scratch closure and biocompatibility were assessed on human-derived keratinocytes. Release and permeation of the peptides were evaluated in vitro and ex vivo. Wound closure rates and histological evaluations were performed on male Sprague-Dawley rats over 3, 7, and 14 days for the NL010-HAgel formulation. Peptide NL010 was found to be the most suitable candidate among the adamantane CMPs. For a comparative study, peptide NL010 and its palmitic acid analogue, NL009, were loaded into a hyaluronic acid (HA) hydrogel and lyophilized. The CMP hydrogels exhibited porosity (<30 μm) and were viscoelastic solids. The physicomechanical properties of the formulations showed optimal characteristics for application as wound dressings in terms of textural profile. Peptide NL008 exhibited lower bioactivity and cell viability compared to NL009 and NL010 across various concentrations and cell lines. Peptide release from NL009-HAgel and NL010-HA gel was 74% and 83%, respectively. Across an ex vivo porcine skin membrane, the CMP-HAgel showed good permeation and was retained in the epidermis and superficial dermis. CMP-HAgel at 0.1% (w/v) showed better HaCaT cell viabilities. In vitro assays demonstrated that the NL010-HA gel achieved scratch closure (99.9%) within 24 h, while the NL009-HAgel showed scratch closure (93.7%) within the same time frame. In vivo, NL010-HAgel improved healing by enhancing epithelialization and granulation tissue deposition (via fibroblast and collagen responses). The findings of this study suggested that the CMP cell-instructive hydrogel is a promising platform with the potential to accelerate wound healing.

Advancements in Wound Dressing Materials: Highlighting Recent Progress in Hydrogels, Foams, and Antimicrobial Dressings

Recent advancements in wound dressing materials have significantly improved acute and chronic wound management by addressing challenges such as infection control, moisture balance, and enhanced healing. Important progress has been made, especially with hydrogels, foams, and antimicrobial materials for creating optimized dressings. Hydrogels are known for maintaining optimal moisture levels, while foam dressings are excellent exudate absorbents. Meanwhile, antimicrobial dressing incorporates various antimicrobial agents to reduce infection risks. These dressing options reduce wound healing time while focusing on customized patient needs. Therefore, this review highlights the newest research materials and prototypes for wound healing applications, emphasizing their particular benefits and clinical importance. Innovations such as stimuli-responsive hydrogels and hybrid bioengineered composites are discussed in relation to their enhanced properties, including responsiveness to pH, temperature, glucose, or enzymes and drug delivery precision. Moreover, ongoing clinical trials have been included, demonstrating the potential of emerging solutions to be soon translated from the laboratory to clinical settings. By discussing interdisciplinary approaches that integrate advanced materials, nanotechnology, and biological insights, this work provides a contemporary framework for patient-centric, efficient wound care strategies.

New Perspectives of Hydrogels in Chronic Wound Management

Chronic wounds pose a substantial healthcare concern due to their prevalence and cost burden. This paper presents a detailed overview of chronic wounds and emphasizes the critical need for novel therapeutic solutions. The pathophysiology of wound healing is discussed, including the healing stages and the factors contributing to chronicity. The focus is on diverse types of chronic wounds, such as diabetic foot necrosis, pressure ulcers, and venous leg ulcers, highlighting their etiology, consequences, and the therapeutic issues they provide. Further, modern wound care solutions, particularly hydrogels, are highlighted for tackling the challenges of chronic wound management. Hydrogels are characterized as multipurpose materials that possess vital characteristics like the capacity to retain moisture, biocompatibility, and the incorporation of active drugs. Hydrogels' effectiveness in therapeutic applications is demonstrated by how they support healing, including preserving ideal moisture levels, promoting cellular migration, and possessing antibacterial properties. Thus, this paper presents hydrogel technology's latest developments, emphasizing drug-loaded and stimuli-responsive types and underscoring how these advanced formulations greatly improve therapy outcomes by enabling dynamic and focused reactions to the wound environment. Future directions for hydrogel research promote the development of customized hydrogel treatments and the incorporation of digital health tools to improve the treatment of chronic wounds.

Hyaluronidase-responsive hydrogel loaded with magnetic nanoparticles combined with external magnetic stimulation for spinal cord injury repair

Spinal cord injury (SCI) is a neurological condition that causes significant loss of sensory, motor, and autonomic functions below the level of injury. Current clinical treatment strategies often fail to meet expectations. Hyaluronidase is typically associated with tumor progression and bacterial infections. Analysis showed that hyaluronidase also persistently increased in a rat total excision model. In this study, we designed a highly biocompatible dual-responsive hydrogel. Hyaluronic acid (HA)-Gelatin (Gel) served as the base for the hydrogel, crosslinked via an amide reaction to form the hydrogel. The hydrogel was further combined with Neurotrophic growth factor (NGF) and Fe3O4 nanoparticles, exhibiting low toxicity, good mechanical properties, self-healing ability, and sustained drug release. In cellular experiments, the novel hydrogel significantly promoted neural axon growth and development under an external magnetic field. Therapeutic results were confirmed in a rat spinal cord resection model, where inflammation was reduced, chondroitin sulfate proteoglycans decreased and a favorable environment for nerve regeneration was provided; neural regeneration improved hind limb motor function in SCI rats. These results underscore the therapeutic potential of hydrogel.

Water triggered injectable polylactic acid hydrogel based on zwitterionic sulfobetaine modification for incompressible bleeding and tissue anti-adhesion

Massive blood loss is the main cause of prehospital trauma-related death, the development of rapid and effective hemostatic materials is imminent. Injectable hydrogels have the advantages of covering irregular bleeding sites and quickly closing the wound. However, its inherent viscosity can easily precipitate tissue adhesion in vivo and other complications. Based on the anti-protein properties of zwitterion and our previous work about in situ hemostatic/anti-adhesion hydrogel material, we have synthesized a series of injectable hydrogel composed of sulfobetaine-modified polylactic acid (PLA) and gelatin (Gel). These hydrogels could form a smooth film structure by simple water triggering, thereby conferring anti-adhesive properties. We visualized the changes in surface hydrophobicity using fluorescent probes and demonstrated tissue adhesion, rapid hydrophobic interface response, as well as rapid hemostasis for incompressible wounds through in vivo and in vitro experiments. Additionally, we explored the application of hydrogel materials in the scenario of postoperative bleeding, which can effectively prevent unnecessary adhesion through rapid film formation and the anti-protein property of sulfobetaine. We believe that this multifunctional hemostatic hydrogel has the potential to serve as a prehospital emergency treatment of incompressible bleeding and benefit to the postoperative recovery of patients.

Quaternized chitosan-based biomimetic nanozyme hydrogels with ROS scavenging, oxygen generating, and antibacterial capabilities for diabetic wound repair

Management of chronic diabetic wounds is challenging due to excess reactive oxygen species (ROS), hypoxia, persistent inflammation, and bacterial infection within the wound microenvironment. For addressing the aforementioned concern, we have developed a multifunctional hydrogel dressing (PMT-C@PhM) based on chitosan with self-healing, adhesive, antibacterial, and antioxidant capacities for therapeutic diabetic wounds. The hydrogel dressing consisted of quaternary ammonium salt- and catechol- modified chitosan (CQCS), thioctic acid-functionalized poly(ethylene glycol)s (PEGs), and polydopamine-coated honeycomb manganese dioxide nanoparticles (hMnO2@PDA NPs). The nanozyme-modified hydrogel exhibits superoxide dismutase (SOD) and catalase (CAT) activities to scavenge ROS while generating oxygen to alleviate oxidative stress and hypoxic environment in wounds, and to attenuate the inflammatory response through modulating macrophage polarization. The PMT-C@PhM hydrogel is effective in the treatment of diabetic wound infections caused by Staphylococcus aureus, and relieves oxidative stress, inhibits inflammation, and promotes neovascularization and dermal collagen synthesis thus providing favorable conditions for accelerated wound healing. In conclusion, the aforementioned approach offers a biosafe, straightforward, and efficient strategy for the management of diabetic wounds.

Formulation and evaluation of n-acetyl cysteine loaded bi-polymeric physically crosslinked hydrogel with antibacterial and antioxidant activity for diabetic wound dressing

Diabetic wounds have become a serious global health concern, with a growing number of patients each year. Diabetic altered wound healing physiology, as well as resulting complications, make therapy difficult. Hence, diabetic wound healing necessitates a multidisciplinary strategy. This study focused on the formulation, statistical optimization, ex vivo, and in vitro evaluation of a diabetic wound healing by n-acetyl cysteine (NAC) loaded hydrogel. The objective of the study is to formulate n-acetyl loaded hydrogel with different ratio (1:1, 1:2, 1:3, 2:1) of sodium alginate and guar gum. The antibacterial and antifungal assessment against the viability of Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S.aureus) and Candida albicans (C. albicans) was conducted after determining the in vitro drug release profile. The results of the experiment demonstrated that the formulation F3 was an optimal formulation on triplicate measurement with a pH of 6.2 ± 0.168, and a density of 1.026 ± 0.21. In vitro cell line study exhibited F3 has potential role in cell adhesion and proliferation might be beneficial to tissue regeneration and wound healing. The results imply that F3 may be helpful for the quick healing of diabetic wounds by promoting angiogenesis and also by scavenging free oxygen radicals.

Enhanced Mechanical Strength and Sustained Drug Release in Carrier-Free Silver-Coordinated Anthraquinone Natural Antibacterial Anti-Inflammatory Hydrogel for Infectious Wound Healing

The persistent challenge of healing infectious wounds and the rise of bacterial resistance represent significant hurdles in contemporary medicine. In this study, based on the natural small molecule drug Rhein self-assembly to form hydrogels and coordinate assembly with silver ions (Ag+), a sustained-release carrier-free hydrogel with compact structure is constructed to promote the repair of bacterial-infected wounds. As a broad-spectrum antimicrobial agent, Ag+ can avoid the problem of bacterial resistance caused by the abuse of traditional antibiotics. In addition, due to the slow-release properties of Rhein hydrogel, continuous effective concentration of Ag+ at the wound site can be ensured. The assembly of Ag+ and Rhein makes the hydrogel system with enhanced mechanical stability. More importantly, it is found that Rhein effectively promotes skin tissue regeneration and wound healing by reprogramming M1 macrophages into M2 macrophages. Further mechanism studies show that Rhein realizes its powerful anti-inflammatory activity through NRF2/HO-1 activation and NF-κB inhibition. Thus, the hydrogel system combines the excellent antibacterial properties of Ag+ with the excellent anti-inflammatory and tissue regeneration ability of Rhein, providing a new strategy for wound management with dual roles.

Oxidized Bacterial Cellulose Membranes Immobilized with Papain for Dressing Applications: Physicochemical and In Vitro Biological Properties

This research consolidates our group's advances in developing a therapeutic dressing with innovative enzymatic debridement, focusing on the physicochemical and in vitro biological properties of papain immobilized in wet oxidized bacterial cellulose (OxBC-Papain) dressing. OxBC membranes were produced with Komagataeibacter hansenii oxidized with NaIO4, and papain was immobilized on them. They were characterized in terms of enzyme stability (over 100 days), absorption capacity, water vapor transmission (WVT), hemocompatibility, cytotoxicity, and cell adhesion. The OxBC-Papain membrane showed 68.5% proteolytic activity after 100 days, demonstrating the benefit of using the OxBC wet membrane for papain stability. It had a WVT rate of 678 g/m2·24 h and cell viability of 99% and 86% for L929 and HaCat cells, respectively. The membranes exhibited non-hemolytic behavior and maintained 26% clotting capacity after 1 h. The wet OxBC-Papain membrane shows significant potential as a natural biomolecule-based therapeutic dressing for wound care, offering efficient debridement, moisture maintenance, exudate absorption, gas exchange, and hemostasis without cytotoxic effects or cell adhesion to the dressing. Further research, especially using in vivo models, is needed to assess its efficacy in inducing epithelialization. This study advances stomatherapy knowledge, providing a cost-effective solution for enzymatic debridement in healthcare.

Integrating Cellulose Microfibrils and Ellagitannins from Rambutan Peel with Gelatin for Production of Synergistic Biobased Hydrogels

The pursuit of renewable and eco-friendly raw materials for biobased materials is a growing field. This study utilized ellagitannin and cellulose microfibrils derived from rambutan peel waste alongside gelatin to develop eco-conscious hydrogels. The cellulose/gelatin hydrogels were formulated in two weight ratios (0.5:1 to 1:1), and the influence of gelatin on the chemical composition and rheology was studied. Composite hydrogels, functionalized with an ellagitannin-rich extract, exhibited a remarkable enhancement of up to 14-fold in compressive strength. The hydrogels also demonstrated antimicrobial properties, reducing the Staphylococcus aureus colony count within 24 h. The hydrogel, derived from rambutan peel waste, is biocompatible and could potentially be explored for biomedical applications such as drug delivery systems, and wound dressings. This suggests that it might offer significant value for sustainable materials science, although specific applications have yet to be tested.

A Double Network Composite Hydrogel with Self-Regulating Cu2+/Luteolin Release and Mechanical Modulation for Enhanced Wound Healing

Designing adaptive and smart hydrogel wound dressings to meet specific needs across different stages of wound healing is crucial. Here, we present a composite hydrogel, GSC/PBE@Lut, that offers self-regulating release of cupric ions and luteolin and modulates mechanical properties to promote chronic wound healing. The double network hydrogel, GSC, is fabricated through photo-cross-linking of gelatin methacrylate, followed by Cu2+-alginate coordination cross-linking. On one hand, GSC allows for rapid Cu2+ release to eliminate bacteria in the acidic pH environment during inflammation and reduces the hydrogel's mechanical strength to minimize tissue trauma during early dressing changes. On the other hand, GSC enables slow Cu2+ release during the proliferation stage, promoting angiogenesis and biocompatibility. Furthermore, the inclusion of pH- and reactive oxygen species (ROS)-responsive luteolin nanoparticles (PBE@Lut) in the hydrogel matrix allows for controlled release of luteolin, offering antioxidant and anti-inflammatory effects and promoting anti-inflammatory macrophage polarization. In a murine model of Staphylococcus aureus infected wounds, GSC/PBE@Lut demonstrates exceptional therapeutic benefits in antibacterial, anti-inflammatory, angiogenic, and tissue regeneration. Overall, our results suggest that smart hydrogels with controlled bioactive agent release and mechanical modulation present a promising solution for treating chronic wounds.

Recent Advances in the Degradability and Applications of Tissue Adhesives Based on Biodegradable Polymers

In clinical practice, tissue adhesives have emerged as an alternative tool for wound treatments due to their advantages in ease of use, rapid application, less pain, and minimal tissue damage. Since most tissue adhesives are designed for internal use or wound treatments, the biodegradation of adhesives is important. To endow tissue adhesives with biodegradability, in the past few decades, various biodegradable polymers, either natural polymers (such as chitosan, hyaluronic acid, gelatin, chondroitin sulfate, starch, sodium alginate, glucans, pectin, functional proteins, and peptides) or synthetic polymers (such as poly(lactic acid), polyurethanes, polycaprolactone, and poly(lactic-co-glycolic acid)), have been utilized to develop novel biodegradable tissue adhesives. Incorporated biodegradable polymers are degraded in vivo with time under specific conditions, leading to the destruction of the structure and the further degradation of tissue adhesives. In this review, we first summarize the strategies of utilizing biodegradable polymers to develop tissue adhesives. Furthermore, we provide a symmetric overview of the biodegradable polymers used for tissue adhesives, with a specific focus on the degradability and applications of these tissue adhesives. Additionally, the challenges and perspectives of biodegradable polymer-based tissue adhesives are discussed. We expect that this review can provide new inspirations for the design of novel biodegradable tissue adhesives for biomedical applications.