Modern Wound Dressings: Hydrogel Dressings

Skin-inspired elastomer-hydrogel Janus fibrous membrane creates a superior pro-regenerative microenvironment toward complete skin regeneration

The complete regeneration of deep cutaneous wounds remains a challenge. Development of advanced biomaterials that more closely resemble the natural healing environments of skin is a promising strategy. In the present study, inspired by the human skins, an elastomer-hydrogel bilayer fibrous membrane was fabricated for cutaneous wound healing. The elastomer layer, made of poly (trimethylene carbonate) (PTMC), mimics human epidermis, including a similar wettability (around 80°), a compact structure, flexibility, excellent moisture retention, and bacterial pathogen blocking. The hydrogel fiber layer that directly contacts the wound surface was made of hydrophilic gelatin hydrogel fibers, providing an advanced pro-regeneration microenvironment for wound healing, including a moist environment and a mesh-like structure and patterns. Bioactive agents (e.g. stem cell-derived exosomes) could be feasibly incorporated into the hydrogel fiber layer to further enhance the therapeutic outcome. In vivo studies demonstrated that such biomimetic elastomer-hydrogel hybrid fibrous membrane could dramatically enhance the skin regeneration as evidenced by faster wound closure rates, enhanced vascularization, promoted collagen deposition, reduced inflammation, and promoted skin appendage regeneration. Our work provides a new avenue for designing biomimetic wound dressings for cutaneous wound healing.

Multifunctional (Co3Fe)(S2)4-ion-microneedle patch: Synergistic antimicrobial, anti-inflammatory and cell proliferation for accelerating wound healing

Preventing bacterial infection and accelerating wound closure are critical for wound healing. Herein, a novel multifunctional polyvinyl alcohol-polyvinylpyrrolidone (PVA-PVP) microneedle (MN) patch embedded with enzyme-like activity (Co3Fe)(S2)4 (CFS) nanoparticles and metal ions (Co2+ and Fe3+) was systematically synthesized for the management of bacteria-infected wounds. CFS regulated redox homeostasis and achieved bacterial eradication while concomitantly alleviating oxidative damage. Specifically, CFS generated reactive oxygen species (ROS) to eliminate bacteria and concurrently attenuated cellular inflammation by scavenging ROS through their superoxide dismutase-like (SOD) activity. Meanwhile, the results of RNA transcriptome sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) analyses indicated that Co2+ and Fe3+ can inhibit inflammatory responses in mice by modulating the IL-17 and NF-κB signaling pathways. Therefore, CFS-ion-MN significantly enhanced the healing of wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) in mice model without eliciting systemic toxicity. Overall, this study offers an innovative methodology for the development of composite materials for the effective treatment of wounds.

Quaternized chitosan-based injectable self-healing hydrogel for improving wound management in aging populations

The clinical management and treatment of skin wounds in the elderly present significant challenges due to changes in skin structure and function. This study introduces a novel injectable self-healing hydrogel composed of quaternized chitosan and carboxymethyl chitosan (HACC/CMCS, HC), designed through electrostatic interactions. Its excellent injectability and self-healing properties enhance the application of hydrogel dressings and prolong their functional lifespan. Moreover, the adhesion and flexibility of HC hydrogel contribute to their stability in highly dynamic regions, thereby preventing detachment and enhancing their hemostatic function. The material exhibits excellent biocompatibility and possesses antibacterial properties that protect wounds from external microbial damage, thereby reducing the risk of infection while maintaining a moist environment that facilitates healing. Importantly, the in vivo test have demonstrated that the HC hydrogel significantly enhances collagen deposition, reduces senescent cell accumulation, and accelerates wound closure. Therefore, this study offers a safe, effective, and cost-efficient solution for managing wounds in the aging population.

Evaluation and characterization of framycetin sulphate loaded hydrogel dressing for enhanced wound healing

BACKGROUND

Hydrogels loaded with antibiotics can be an effective drug delivery systemfor treating skin diseases or conditions such asinburns and wound healing.

OBJECTIVES

The current research work was planned to preparea hydrogel dressing for an effective wound healing. The hydrogel formulation was aimed to provide sustained drug release, reducing the frequency of repeated applying the transdermal drug formulation or patch.

METHODS

Different polymers, polyvinyl alcohol, sodium alginate, and polyvinyl pyrrolidonein varying ratios were used to prepare hydrogels by freeze-thawing method. The prepared hydrogel formulations were loaded with framycetinsulphate (FC-S), a topical aminoglycoside.

RESULTS

Swelling behaviour, drug release pattern, wereinvestigated.Equilibrium and dynamic studies were conducted at pH 7.4. The prepared hydrogel formulations showed Euilibriumswellingratio of 197.5%. The in-vitro release pattern of FC-Shydrogels was determined by dissolution testing. The prepared hydrogels were characterized by scanning electron microscopy (SEM)andfourier transform infrared (FTIR)spectroscopy.Animal study was conducted on rats to evaluatethe in-vivo therapeutic effectiveness of FC-S hydrogels in wound healing. For that purpose,wounds were induced in the animals. The drug loaded hydrogel dressing was effiecent in wound heaing as the wound treated with FC-S loaded hydrogel was almost completely healed (97%) on the fifth day in comparison to commercially available product (Sofra Tulle gauze) that healed 86%, whereas free FC-S manifested healing at 76%.

CONCLUSION

It was observed that hydrogel dressing loaded with FC-S was therapeutically more efficient and can be used as a potential candidate for wound healing.

Functional hydrogels for accelerated wound healing: advances in conductive hydrogels and self-powered electrical stimulation

Compared to traditional dressings, hydrogel dressings not only protect the wound surface and prevent bacterial infection but also possess excellent moisturizing properties, which can provide an optimal moist environment for wound healing, and exhibit good biocompatibility, making them considered the best wound treatment materials. This review focuses on the research status and application progress of various functional hydrogel dressings, such as hemostatic, antimicrobial, anti-inflammatory, antioxidant, and conductive hydrogels. It proposes the combination of conductive hydrogels with flexible solar cells to form self-powered devices. Compared to traditional externally powered devices, this approach can reduce carbon footprints by utilizing clean energy, aligning with carbon neutrality policy requirements. Additionally, it eliminates the need for frequent battery replacement or power connections, effectively saving labor and operational costs. Self-powered devices can convert solar energy into electrical energy, which is conducted to the wound site through hydrogels, generating continuous electrical stimulation (ES). This electrical stimulation guides the directional migration of keratinocytes and fibroblasts toward the center of the wound; activates the MAPK/ERK signaling pathway to accelerate the cell cycle process, and upregulates the expression of vascular endothelial growth factor, thereby inducing endothelial cell proliferation and lumen formation. These multiple mechanisms work synergistically to promote wound healing. Finally, the review provides an outlook on the emergence and applications of multifunctional hydrogels and stimuli-responsive hydrogels, highlighting common challenges in the future development of hydrogels, such as weak mechanical strength and poor long-term stability, as well as feasible solutions to these issues.

Advances in cellulose-based hydrogels: tunable swelling dynamics and their versatile real-time applications

Cellulose-derived hydrogels have emerged as game-changing materials in biomedical research, offering an exceptional combination of water absorption capacity, mechanical resilience, and innate biocompatibility. This review explores the intricate mechanisms that drive their swelling behaviour, unravelling how molecular interactions and network architectures work synergistically to enable efficient water retention and adaptability. Their mechanical properties are explored in depth, with a focus on innovative chemical modifications and cross-linking techniques that enhance strength, elasticity, and functional versatility. The versatility of cellulose-based hydrogels shines in applications such as wound healing, precision drug delivery, and tissue engineering, where their biodegradability, biocompatibility, and adaptability meet the demands of cutting-edge healthcare solutions. By weaving together recent breakthroughs in their development and application, this review highlights their transformative potential to redefine regenerative medicine and other biomedical fields. Ultimately, it emphasizes the urgent need for continued research to unlock the untapped capabilities of these extraordinary biomaterials, paving the way for new frontiers in healthcare innovation.

Innovating chitosan-based bioinks for dermal wound healing: Current progress and future prospects

The field of three-dimensional (3D) bio/printing, known as additive manufacturing (AM), heavily relies on bioinks possessing suitable mechanical properties and compatibility with living cells. Among the array of potential hydrogel precursor materials, chitosan (CS) has garnered significant attention due to its remarkable physicochemical and biological attributes. These attributes include biodegradability, nontoxicity, antimicrobial properties, wound healing promotion, and immune system activation, making CS a highly appealing hydrogel-based bioink candidate. This review explores the transformative potential of CS-based bioink for enhancing dermal wound healing therapies. We highlight CS's unique qualities that make it an optimal choice for bioink development. Advancements in 3D bio/printing technology for tissue engineering (TE) are discussed, followed by an examination of strategies for CS-based bioink formulation and their impacts on wound healing. To address the progress in translating advanced wound healing from lab to clinic, we highlight the current and ongoing research in CS-based bioink for 3D bio/printing in skin wound healing applications. Finally, we explore current evidence, commercialization prospects, emerging innovations like 4D printing, and the challenges and future directions in this promising field.

Review on application of silk fibroin hydrogels in the management of wound healing

Wounds are regarded as disruptions in the integrity of human skin tissues, and the process of wound healing is often characterized as protracted and complex, primarily due to the potential infection or inflammation caused by microorganisms. The quest for innovative solutions that accelerate wound healing while prioritizing patient safety and comfort has emerged as a focal point. Within this pursuit, silkworm silk fibroin-a natural polymer extracted from silk cocoons-exhibits a distinctive combination of properties including biocompatibility, biodegradability, superior mechanical strength, water absorption, and low immunogenicity, which align closely with the demands of contemporary wound care. Its remarkable biocompatibility facilitates seamless integration with host tissues, thereby minimizing the risk of rejection or adverse reactions. Furthermore, its intrinsic degradability permits controlled release of therapeutic agents, promoting an optimal microenvironment conducive to healing. This review investigates the multifaceted potential of silk fibroin specifically as a wound dressing material and examines the intricate nuances associated with its application in hydrogels for wound healing, aiming to furnish a thorough overview for both researchers and clinicians. By scrutinizing underlying mechanisms, current applications, and prospective directions, we aspire to cultivate new insights and inspire innovative strategies within this rapidly evolving field.

Cell membrane-derived nanovesicles as extracellular vesicle-mimetics in wound healing

Cell membrane-derived nanovesicles (NVs) have emerged as promising alternatives to extracellular vesicles (EVs) for wound healing applications, addressing the limitations of traditional EVs, which include insufficient targeting capability, low production yield, and limited drug-loading capacity. Through mechanical cell extrusion methods, NVs exhibit superior characteristics, demonstrating enhanced yield, stability, and purity compared to natural EVs. These NVs can be derived from various membrane sources, including single cell types (stem cells, blood cells, immune cells, and bacterial membranes), hybrid cell membranes and cell membranes mixed with liposomes, with each offering unique therapeutic properties. The integration of genetic engineering and surface modifications has further enhanced NV functionality, enabling precise targeting and improved drug delivery capabilities. Recent advances in NV-based therapies have demonstrated their potential across multiple biomedical applications. Although challenges persist in terms of standardization, storage stability, and clinical translation, the combination of natural cell-derived functions with artificial modification potential positions NVs as a promising platform for next-generation therapeutic delivery systems, thereby offering new possibilities in wound healing applications. Finally, we explore the challenges and future prospects of translating NV-based therapeutics into clinical practice, providing insights into the future development of this innovative approach in wound healing and tissue repair.

Anionic polyelectrolyte-regulated cellulose nanocrystal-based hydrogels for controllable drug release

The application of inorganic salt-regulated Hofmeister effects in cellulose nanocrystals (CNC)-based hydrogels is hindered by limitations, including poor biocompatibility and difficulties in achieving precise drug release. In this study, we show that the anionic polyelectrolyte regulated Hofmeister effect promotes the aggregation and crystallization of CNC and polyvinyl alcohol (PVA) chains. This structural transformation significantly enhances the controllability of drug release in CNC-based hydrogels. The incorporation of anionic polyelectrolytes into CNC-based hydrogels creates a semi-interpenetrating polymer network (semi-IPN), significantly enhancing their mechanical properties and improving in vitro drug release controllability. Our hydrogel exhibits significant flexibility in controlling both drug release duration and capacity, with adjustable release times ranging from 16 to 52 h and tunable drug release capacities between 10.13 mg/g and 19.21 mg/g. Furthermore, antibacterial and cytotoxicity assays confirm its favorable biocompatibility and moderate antibacterial properties. Overall, our research findings emphasize that the preparation of cellulose-based hydrogels using polyelectrolytes has certain flexible regulatory functions in drug release.

Breathable, Moisturizing Biomimetic Wound Dressing with Broad-Spectrum Antimicrobial Properties

Maintaining wound breathability and preventing infection are crucial for moist wound healing. However, existing hydrogel dressings suffer from poor breathability and clinically used antimicrobial agents such as antibiotics, metal nanoparticles, and natural antimicrobial substances face challenges including resistance, toxicity, and high extraction costs, respectively. Inspired by the antimicrobial properties of airway surface liquid (ASL), a biomimetic moisturizing and antibacterial hydrogel dressing (BMAHD) is designed. It combines polyvinyl alcohol (PVA) hydrogel with ordinary gauze to achieve high breathability, while also secreting a water-glycerol mixture to moisturize the wound. Interestingly, Na2CO3 secreted by dressing achieves broad-spectrum bactericidal effects, with up to 99% sterilization rates within 24 h. Furthermore, co-cultivation experiments with mouse embryonic fibroblasts (L929) and sheep red blood cells (SRBC) demonstrate excellent cellular compatibility of the dressing. To prove of concept, the animal model confirms that BMAHD significantly promotes wound healing. The BMAHD provides a valuable reference for the design of novel medical dressings.

Proanthocyanidin capsules remodel the ROS microenvironment via regulating MAPK signaling for accelerating diabetic wound healing

Defective diabetic wound healing is a major clinical challenge, where hyperglycemia at the wound site induces excessive reactive oxygen species (ROS) which activate the MAPK pathway (particularly p38 MAPK), resulting in sustained release of inflammatory factors and cellular damage/apoptosis. Polyphenols are efficient ROS scavengers which reduce the level of inflammation at the wound site and promote wound healing, but the low bioavailability limits their biomedical application. This study developed a simple and highly efficient method for preparing proanthocyanidin (PC) capsules through hydrogen bonding and hydrophobic interactions among PC molecules. PC capsules can continuously scavenge free radicals and release proanthocyanidins, significantly enhancing their bioavailability. A single dose of PC capsules accelerates wound healing in diabetic mice by regulating the p38 MAPK signaling cascade, reducing inflammatory mediator concentration, inhibiting cell apoptosis, and remodeling the wound microenvironment. This research makes an important contribution to the field of enhancing polyphenol bioavailability for wound healing and reveals the potential of modulating the MAPK pathway for treating other inflammation and oxidative stress-related diseases.

A self-powered casein hydrogel E-dressing with synergistic photothermal therapy, electrical stimulation, and antibacterial effects for chronic wound management

Triboelectric nanogenerators (TENGs) have recently demonstrated great application potential for accelerating wound healing in the field of medical research due to their unique electrical stimulation effect. Among the various types of TENGs, solid-liquid TENGs have attracted much attention due to their significant advantages, such as high contact-separation efficiency and a wide range of liquid motion. Therefore, this study innovatively proposed a solid-liquid biphasic TENG electronic dressing constructed from a casein hydrogel enhanced by the metal-organic framework Zeolitic Imidazolate Framework-8 (ZIF-8). This hydrogel dressing comprised sodium caseinate (SC)/multi-walled carbon nanotubes-polydopamine@polydopamine (MWCNT@PDA)/polyacrylamide (PAM)/ZIF-8. It ingeniously integrates multiple functions such as photothermal, photodynamic antibacterial, and electrical stimulation therapies, thereby establishing a new multimodal synergistic treatment paradigm. Notably, the addition of ZIF-8 not only controlled photothermal release of antibacterial agents but also facilitates the development of a distinctive solid-liquid biphasic operational modality in TENG system, achieving a 131 V peak output voltage through significant enhancement of electrical performance parameters. In addition, the TENG-based system adopts a non-contact electrical stimulation method for wound treatment, fundamentally reducing the risk of infection caused by direct contact. Experiments using mouse fibroblasts revealed that the simultaneous real-time use of near-infrared light and TENG can significantly improve the cell migration process. Empirical studies on animals demonstrated that it could accelerate tissue regeneration and wound healing by increasing collagen deposition and angiogenesis. Based on these results, this study provides new perspectives for the developing intelligent biomedical composites for future wound management. STATEMENT OF SIGNIFICANCE: Chronic wounds have become a major threat to global medical and health fields due to pathogenic infections. Traditional wound dressings mostly focus on passive healing, which has limited effectiveness. To overcome these limitations, we developed an electronic dressing of a casein-based hydrogel TENG enhanced by a MOF. This electronic dressing combines photothermal, photodynamic antibacterial, and electrical stimulation functions and efficiently promotes wound healing through multifunctional synergy. This research provides a promising solution for diabetic wound care and a broader field of chronic wound treatment. It is a solid step in the scientific exploration of interdisciplinary integration, offering new ideas for making the wound treatment field more intelligent, efficient, and precise.

Chlorella-encapsulated living hydrogel based on gelatin and carrageenan with oxygen production, hemostatic and antibacterial capacity for promoting wound healing

Hypoxia can prolong the healing time of wounds and oxygen delivery to the hypoxic tissue has been reported an effective strategy for promoting wound regeneration. Bacterial infections can interfere with the wound healing process, leading to poor skin regeneration and even more serious complications, which is also an urgent issue to be solved during the process of wound healing. To address the problem of delayed wound healing caused by hypoxia and bacterial infections, we fabricated a series of Chlorella-loaded hydrogels (CK) using gelatin, κ-carrageenan and I-carrageenan as matrixes, which introduced Chlorella and ampicillin conferred oxygen-producing and antimicrobial capacity to the hydrogel. The CK hydrogels possessed good mechanical and adhesive properties, as well as the capability of efficient and sustained oxygen release. The hydrogels possessed outstanding hemostatic ability, excellent blood and cell compatibility, which also owned excellent antibacterial capacity against E. coli and S. aureus. More notably, the in vivo evaluation revealed that the hydrogel can accelerate wound healing by promoting collagen deposition, which may as a promising potential wound dressing for hypoxic wound healing.

Rapid in situ formation of a double cross-linked network hydrogels for wound healing promotion

The persistent challenge lies in accelerating wound healing. Bioactive hydrogels with in situ formation properties ensure that the dressing completely adheres to the wound and isolates it from external bacteria and microorganisms in order to meet the needs of damaged skin tissue for rapid hemostasis and wound healing. In this paper, hydrogel dressing that Polyacrylamide/Sodium alginate grafted with dopamine/Gelatin grafted with glycidyl methacrylate doped with Angelica sinensis polysaccharide was prepared (PDGA). Chemical cross-linking of PAAM by adding cross-linking agent to initiate free radical polymerization and photocross-linking by free radical polymerization of GMA-GEL under UV light irradiation are two cross-linking modes to construct dual-cross-linking network of PDGA hydrogel dressing. The hydrogel remains fluid when placed in a sealed syringe and solidify rapidly by photocross-linking when placed on the wound. Furthermore, the hydrogel demonstrated excellent biocompatibility and hematological safety. The interaction between angelica polysaccharides and integrins on the platelet surface facilitated an augmentation in platelet adhesion, activation, and aggregation, ultimately inducing rapid coagulation of the blood within 130 s in a mouse tail vein hemorrhage model. ASP can promote tissue healing by promoting cell proliferation around wounds and accelerating the formation of new blood vessels. In a mouse skin defect model, collagen deposition, blood vessel formation, hair follicle regeneration, and granulation tissue formation were observed due to the presence of angelica polysaccharides, showing significantly superior wound healing properties when compared to Tegaderm™ film. In addition, the expression of CD31 in skin wounds treated with PDGA was significantly upregulated. Consequently, PDGA multifunctional dressings exhibit considerable potential for in vitro hemostasis and skin wound repair applications.

Dynamic mechanical analysis of alginate/gellan hydrogels under controlled conditions relevant to environmentally sensitive applications

Hydrogels are natural/synthetic polymer-based materials with a large percentage of water content, usually above 80 %, and are suitable for many application fields such as wearable sensors, biomedicine, cosmetics, agriculture, etc. However, their performance is susceptible to environmental changes in temperature, relative humidity, and mechanical deformation due to their aqueous and soft nature. We investigate the mechanical response of both filled and unfilled alginate/gellan hydrogels using a combined axial-torsional rheometric approach with cylindrical samples of large length/diameter ratio under controlled temperature and relative humidity. Dynamic Mechanical Analysis (DMA) is performed on the same specimen in both torsion and extension under identical experimental conditions. This rheometric approach ensures consistent initial and boundary conditions, which are essential for a reliable estimation of viscoelastic moduli G* and E*, and their dependence on temperature, frequency, and relative humidity. Our findings indicate that humidity critically affects the mechanical response of the material due to sample volume shrinkage, necessitating corrections to the viscoelastic moduli. We also find temperature plays a role only at low/medium relative humidity values. The inclusion of fillers leads to a modest increase in the elasticity of the hydrogel, probably due to restricted water diffusion out of the sample. In connection with the latest, unfilled samples in breaking tests present only slippage due to twist-induced surface water excess, opposite to breakage events shown by filled samples, probably linked to restricted water diffusion.

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.

Nanoparticle-Enhanced Collagen Hydrogels for Chronic Wound Management

Chronic wound infections present a persistent medical challenge; however, advancements in wound dressings and antimicrobial nanomaterials offer promising solutions for improving healing outcomes. This study introduces a hydrothermal synthesis approach for producing zinc oxide (ZnO) and copper oxide (CuO) nanoparticles, subsequently incorporated into PLGA microspheres and embedded within collagen hydrogels. The nanoparticles' physicochemical properties were characterized using X-ray diffraction (XRD) to confirm crystalline structure, scanning electron microscopy (SEM) for surface morphology, and Fourier-transform infrared spectroscopy (FT-IR) to verify functional groups and successful hydrogel integration. The hydrogels were tested for antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, which are key pathogens in chronic wounds. Biocompatibility was assessed using the human HaCat keratinocyte cell line. Both ZnO- and CuO-loaded hydrogels exhibited broad-spectrum antimicrobial efficacy. Cytocompatibility tests demonstrated that both ZnO- and CuO-loaded hydrogels sustain cell viability and proliferation, highlighting their biocompatibility and suitability for chronic wound healing applications, with superior biological performance of ZnO-loaded hydrogels. Furthermore, the distinct antimicrobial profiles of ZnO and CuO hydrogels suggest their tailored use based on wound microbial composition, with CuO hydrogels excelling in antibacterial applications and ZnO hydrogels showing potential for antifungal treatments. These results underscore the potential of nanoparticle-based collagen hydrogels as innovative therapeutic tools for managing chronic wounds.

Next-generation biopolymer gels: innovations in drug delivery and theranostics

Biopolymers or natural polymers like chitosan, cellulose, alginate, collagen, etc. have gained significant interest recently due to their remarkable tunable properties that make them appropriate for a variety of applications & play a crucial role in everyday life. The features of biopolymers which include biodegradability, biocompatibility, sustainability, affordability, & availability are vital for creating products for use in biomedical fields. Apart from these characteristics, smart or stimuli-responsive biopolymers also show a distinctive property of being susceptible to various factors like pH, temperature, light intensity, & electrical or magnetic fields. The current review would present a brief idea about smart biopolymer gels along with their biomedical applications. The use of smart biopolymers gels as theranostic agents are also discussed in the present review. This review also focuses on the application of biopolymers in the fields of drug delivery, cancer treatment, tissue engineering & wound healing. These areas demonstrate the development and utilization of different types of biopolymers in current biomedical applications.

Biomimetic Hydrogels - Tools for Regenerative Medicine, Oncology, and Understanding Medical Gas Plasma Therapy

Biomimetic hydrogels enable biochemical, cell biology, and tissue-like studies in the third dimension. Smart hydrogels are also frequently used in tissue engineering and as drug carriers for intra- or extracutaneous regenerative medicine. They have also been studied in bio-sensor development, 3D cell culture, and organoid growth optimization. Yet, many hydrogel types, adjuvant components, and cross-linking methods have emerged over decades, diversifying and complexifying such studies. Here, an evaluative overview is provided, mapping potential applications to the corresponding hydrogel tuning. Strikingly, hydrogels are ideal for studying locoregional therapy modalities, such as cold medical gas plasma technology. These partially ionized gases produce various reactive oxygen species (ROS) types along with other physico-chemical components such as ions and electric fields, and the spatio-temporal effects of these components delivered to diseased tissues remain largely elusive to date. Hence, this work outlines the promising applications of hydrogels in biomedical research in general and cold plasma science in particular and underlines the great potential of these smart scaffolds for current and future research and therapy.

The Printed Path to Healing: Advancing Wound Dressings through Additive Manufacturing

Wound care challenges healthcare systems worldwide as traditional dressings often fall short in addressing the diverse and complex nature of wound healing. Given conventional treatments limitations, innovative alternatives are urgent. Additive manufacturing (AM) has emerged as a distinct and transformative approach for developing advanced wound dressings, offering unprecedented functionality and customization. Besides exploring the AM processes state-of-the-art, this review comprehensively examines the application of AM to produce cellular-compatible and bioactive, therapeutic agent delivery, patient-centric, and responsive dressings. This review distinguishes itself from the published literature by covering a variety of wound types and by summarizing important data, including used materials, process/technology, printing parameters, and findings from in vitro, ex vivo, and in vivo studies. The prospects of AM in enhancing wound healing outcomes are also analyzed in a translational and cost-effective manner.

Hydrogel Dressings as Insulin Delivery Systems for Diabetic Wounds

Diabetic wounds are one of the most common and challenging complications of diabetes. Similar to chronic wounds, diabetic wounds are difficult to treat due to prolonged inflammation, a lack of angiogenesis, abnormal differentiation of new scar tissue, and the occurrence of numerous bacterial infections. Moreover, elevated sugar levels in tissues disrupt the healing process by enhancing inflammatory reactions, disrupting signaling pathways, and leading to the production of abnormal biological structures, which contribute to improper cell differentiation. Traditional dressings, such as bandages, gauze, and semi-occlusive foams, are inadequate for diabetic wounds with high exudation; moreover, frequently changing the dressing can cause secondary irritation. Hence, innovative hydrogel dressings are being developed, which, thanks to their soft polymer matrix, provide an ideal substrate for regenerating tissue. Hydrogels also allow for the introduction and controlled release of growth factors, making them a promising solution for treating diabetic wounds. Recently, researchers have focused on insulin, a hormone secreted by the human body to lower blood sugar levels, due to its interesting characteristics, such as supporting anti-inflammatory and proangiogenic processes and stimulating cell migration and proper proliferation. This review discusses the most important aspects of diabetes and diabetic wounds and traditional and innovative treatment methods, particularly hydrogel dressings used as systems for insulin delivery in response to glucose concentration.

Healing wounds with plasma-activated hydrogel therapy

Chronic wound infections are a silent pandemic in danger of becoming a global healthcare crisis. Innovations to control infections and improve healing are required. In the context of this challenge, researchers are exploiting plasma-activated hydrogel therapy (PAHT) for use either alone or in combination with other antimicrobial strategies. PAHT involves the cold atmospheric pressure plasma activation of hydrogels with reactive oxygen and nitrogen species to decontaminate infections and promote healing. This opinion article describes PAHT for wound treatment and provides an overview of current research and outstanding challenges in translating the technology for medical use. A 'blueprint' of an autonomous PAHT is presented in the final section that can move the management and treatment of wounds from the clinical setting to the community.

Revealing the promising era of silk-based nanotherapeutics: a ray of hope for chronic wound healing treatment

Chronic wounds significantly contribute to disability and affect the mortality rate in diabetic patients. In addition, pressure ulcers, diabetic foot ulcers, arterial ulcers, and venous ulcers pose a significant health burden due to their associated morbidity and death. The complex healing process, environmental factors, and genetic factors have been identified as the rate-limiting stages of chronic wound healing. Changes in temperature, moisture content, mechanical strain, and genetics can result in slow wound healing, increased susceptibility to bacterial infections, and poor matrix remodelling. These obstacles can be addressed with natural biomaterials exhibiting antimicrobial, collagen synthesis, and granulation tissue formation properties. Recently, silk proteins have gained significant attention as a natural biomaterial owing to good biocompatibility, biodegradability, reduced immunogenicity, ease of sterilization, and promote the wound healing process. The silk components such as sericin and fibroin in combination with nano(platforms) effectively promote wound repair. This review emphasises the potential of sericin and fibroin when combined with nano(platforms) like nanoparticles, nanofibers, and nanoparticles-embedded films, membranes, gels, and nanofibers.

A composite dressing combining ultralong hydroxyapatite nanowire bio-paper and a calcium alginate hydrogel accelerates wound healing

An acute wound is the most common type of skin injury. Developing wound dressings with excellent mechanical properties, wound protection, comfort, angiogenic capacity and therapeutic effects is significant for effective treatments, yet remains challenging. Herein, we have designed a novel HAP-Alg composite dressing comprising a complementary ultralong hydroxyapatite (HAP) nanowire bio-paper and calcium alginate hydrogel. The HAP bio-paper assembled by ultralong HAP nanowires, in contrast to typical brittle HAP bio-ceramics, exhibits a highly flexible and interwoven structure to enhance the mechanical and protective performance of an alginate hydrogel, and the alginate matrix creates a moist environment for skin regeneration. Therefore, the HAP-Alg composite dressing presents good mechanical properties and high resistance to swelling and shrinkage, along with a reliable bacterial shielding ability. In addition, its moisturizing effect can deliver bioactive calcium ions to promote angiogenesis, accelerate re-epithelialization and reduce scar formation. In vitro studies reveal that the HAP-Alg composite dressing has excellent biocompatibility, promotes cell migration and angiogenesis, and enhances calcium ion influx. In vivo wound models further prove the ability of the HAP-Alg composite dressing to accelerate wound closure, enhance collagen deposition, and induce neovascularization. This work demonstrates that the HAP-Alg composite dressing offers a promising wound dressing for acute wound treatment and protection.

Recent Advances in Asymmetric Wettability Dressings for Wound Exudate Management

The management of wound exudate is of vital importance for wound healing. Exudate accumulation around wound prolongs inflammation and hinders healing. Although traditional dressings can absorb wound exudate, they are unable to drain exudate in time, often resulting in a poor feature with wound healing. In recent years, the appearance of asymmetric wettability dressings has shown great potential in exudate management. Here, we summarize the latest progress of 3 kinds of asymmetric wettability wound dressings in exudate management, including Janus structure, sandwich structure, and gradient structure. The most common Janus structural dressing among asymmetric wettability dressings is highlighted from 2 aspects: single-layer modified Janus structure and double-layer Janus structure. The challenges faced by asymmetric wettability wound dressings are discussed, and the developing trends of smart wound dressings in this field are prospected.

Zn ion-incorporated injected hydrogels with reactive oxygen species and glucose scavenging capacity for diabetic wound healing

Background

Patients with diabetic wounds often experience challenges in the repair process, owing to increased concentration of glucose and reactive oxygen species (ROS). In addition, high glucose levels usually result in bacterial infections, which in turn worsen wound healing. This study aims to develop a multifunctional hydrogel with integrated antibacterial activity, ROS scavenging, and glucose-responsive properties to accelerate healing of infected diabetic wounds.

Methods

A Zn ion-incorporated injected hydrogel was prepared using 4-carboxyphenylboronic acid-modified gelatine, tannic acid, and zinc ions. The spectra were detected using a Fourier transform infrared spectrometer and surface morphologies of hydrogels were obtained using a scanning electron microscopy. The release behavior of Zn ions was investigated using an inductively coupled plasma mass spectrometry instrument. To evaluate the antimicrobial properties of the GPT and GPT@Zn hydrogels, strains of Escherichia coli and Staphylococcus aureus were utilized. Cytocompatibility was evaluated using mouse fibroblasts (L929 cells) and human umbilical vein endothelial cells (HUVECs). Finally, diabetic wound models were constructed in rats to evaluate the effects of hydrogels on wound healing.

Results

The results show that the hydrogels are injectable and have self-healing properties. Moreover, borate ester bonds are formed in the hydrogels, which are responsive to H2O2 and glucose and can eliminate them. At the same time, zinc ions were released, giving the hydrogels good antibacterial efficacy, with antibacterial rates of 99.7% and 99.9% against S. aureus and E. coli, respectively. Furthermore, the hydrogels demonstrated good cell compatibility with L929 cells and HUVECs and increased the gene expression of VEGF, COL I, and COL III because of the addition of zinc ions. Based on the ROS, glucose scavenging capacity, and biological functions of zinc ions, the hydrogels advanced the recovery of S. aureus-contaminated whole skin wounds in diabetic rats.

Conclusions

This study provides a novel treatment strategy for diabetic wound healing by constructing Zn ion-incorporated injected hydrogels with reactive oxygen species and glucose-scavenging capacity.

Current Insight of Peptide-Based Hydrogels for Chronic Wound Healing Applications: A Concise Review

Chronic wounds present a substantial healthcare obstacle, marked by an extended healing period that can persist for weeks, months, or even years. Typically, they do not progress through the usual phases of healing, which include hemostasis, inflammation, proliferation, and remodeling, within the expected timeframe. Therefore, to address the socioeconomic burden in taking care of chronic wounds, hydrogel-based therapeutic materials have been proposed. Hydrogels are hydrophilic polymer networks with a 3D structure which allows them to become skin substitutes for chronic wounds. Knowing that peptides are abundant in the human body and possess distinct biological functionality, activity, and selectivity, their adaptability as peptide-based hydrogels to individual therapeutic requirements has made them a significant potential biomaterial for the treatment of chronic wounds. Peptide-based hydrogels possess excellent physicochemical and mechanical characteristics such as biodegradability and swelling, and suitable rheological properties as well great biocompatibility. Moreover, they interact with cells, promoting adhesion, migration, and proliferation. These characteristics and cellular interactions have driven peptide-based hydrogels to be applied in chronic wound healing.

Encapsulation of Hydrogen Peroxide in PVA/PVP Hydrogels for Medical Applications

Researchers have been investigating the physical and morphological properties of biodegradable polymer and copolymer films, blending them with other chemicals to solve challenges in medical, industrial, and eco-environmental fields. The present study introduces a novel, straightforward method for preparing biodegradable hydrogels based on polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) for medical applications. The resulting PVA/PVP-based hydrogel uniquely combines the water absorbency, biocompatibility, and biodegradability of the polymer composite. For hygiene products and medical uses, such as wound healing, hydrogen peroxide (HP) was encapsulated in the PVA/PVP hydrogels for controlled release application. Incorporating PVP into PVA significantly enhances the hydrogel water absorbency and improves the mechanical properties. However, to mitigate the disadvantage of high water absorbency which could result in undesired early dissolution, efforts were made to increase the water resistance and the mechanical characteristics of these hydrogels using freeze-thaw (F/T) cycles and chemical crosslinking PVA chains with trisodium trimetaphosphate (STMP). The resulting hydrogels serve as environmentally friendly bio-based polymer blends, broadening their applications in medical and industrial products. The structural and morphological properties of the hydrogel were characterized using Fourier transform infrared spectroscopy (FTIR), environmental scanning electron microscope analysis (E-SEM), and water-swelling tests. The HP controlled release rate was evaluated through kinetic release experiments using the ex vivo skin model. The antibacterial activity of the hydrogel films was examined on four medically relevant bacteria: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, with an adapted disk diffusion assay. Using this assay, we also evaluated the antibacterial effect of the hydrogel films over the course of days, demonstrating the HP controlled release from these hydrogels. These findings support further in vivo investigation into controlled HP release systems for improved wound-healing outcomes.

In Situ Formation of Hydrogels Loaded with ZnO Nanoparticles Promotes Healing of Diabetic Wounds in Rats

The challenge of healing diabetic skin wounds presents a significant hurdle in clinical practice and scientific research. In response to this pressing concern, we have developed a temperature-sensitive, in situ-forming hydrogel comprising poly(n-isopropylacrylamide166-co-n-butyl acrylate9) -poly(ethylene glycol) -poly(n-isopropylacrylamide166-co-butyl acrylate9) copolymer, denoted as PEP, in combination with zinc oxide nanoparticles, forming what we refer to as PEP-ZnO hydrogel. The antimicrobial properties of the PEP-ZnO hydrogel against methicillin-resistant Staphylococcus aureus were rigorously assessed by using the bacteriostatic banding method. In vitro evaluations encompassed examinations of hemocompatibility and biocompatibility. The study further employed a diabetic Sprague-Dawley (SD) rat whole-layer trauma model for comprehensive in vivo analyses. In vivo healing assessments revealed the potential of the PEP-ZnO hydrogel, characterized by increased collagen deposition and enhanced vascularization at the trauma site, thus significantly expediting the healing process. Collectively, these findings endorse the PEP-ZnO hydrogel as a safe and effective dressing for addressing chronic wounds in diabetic patients. This hydrogel not only holds promise for improving the quality of life for diabetic individuals grappling with chronic wounds but also represents a noteworthy advancement in wound care.

Injectable Gelatin-Palmitoyl-GDPH Hydrogels as Bioinks for Future Cutaneous Regeneration: Physicochemical Characterization and Cytotoxicity Assessment

Tissue engineering and regenerative medicine have made significant breakthroughs in creating complex three-dimensional (3D) constructs that mimic human tissues. This progress is largely driven by the development of hydrogels, which enable the precise arrangement of biomaterials and cells to form structures resembling native tissues. Gelatin-based bioinks are widely used in wound healing due to their excellent biocompatibility, biodegradability, non-toxicity, and ability to accelerate extracellular matrix formation. However, the role of a novel fatty acid conjugated tetrapeptide, palmitic acid-glycine-aspartic acid-proline-histidine (palmitoyl-GDPH), in enhancing hydrogel performance with human dermal fibroblasts (HDFs) concerning cell survival, proliferation, growth, and metabolism remains poorly understood. This study fabricated gelatin-palmitoyl-GDPH hydrogels at various concentrations (GE_GNP_ELS_PAL12.5 and GE_GNP_ELS_PAL25) using an injectable method and preliminary extrusion-based 3D bioprinting at 24 °C. Physicochemical characterization revealed superior water absorption, biocompatibility, and stability, aligning with optimal wound-healing criteria. In vitro cytotoxicity assays demonstrated >90% cell viability of HDFs cultured on these scaffolds for five days. These results highlight their ability to promote cell survival, proliferation, and adhesion, establishing them as strong contenders for wound healing. This study underscores the potential of gelatin-palmitoyl-GDPH hydrogels as effective bioinks for 3D bioprinting, offering a promising platform for skin tissue engineering and regenerative medicine.

Carbonized Plant Powder Gel for Rapid Hemostasis and Sterilization in Regard to Irregular Wounds

Irregularly shaped wounds cause severe chronic infections, which have attracted worldwide attention due to their high prevalence and poor treatment outcomes. In this study, we designed a new composite functional dressing consisting of traditional Chinese herb carbonized plant powder (CPP) and a polyacrylic acid (PAA)/polyethylenimine (PEI) gel. The rapid gelation of the dressing within 6-8 s allowed the gel to be firmly attached to an irregularly shaped wound surface and avoided powder detachment. In addition, through an infrared thermography analysis, a coagulation assay, and a morphological examination of regenerative tissue in animal wound models, it was found that the dressing substrates had synergistic effects on photothermal sterilization, rapid hemostasis, and anti-inflammatory activity, thereby achieving an 88% wound closure rate on the 9th day after the formation of the wound. This multifunctional hemostatic material is expected to be adaptable to irregular wounds and promote rapid wound healing.

Poly(thioctic acid) Hydrogels Integrated with Self-Healing, Bioadhesion, Antioxidation, and Antibiosis for Infected Wound Treatment

Bacterial infections pose significant challenges in wound healing and are a serious threat to human health. Hydrogels have emerged as an ideal wound dressing due to their three-dimensional network, which facilitates exudate absorption and maintains a moist environment conducive to healing. Herein, we developed integrated hydrogels composed of poly(thioctic acid) (PTA), polydopamine (PDA), and curcumin (Cur). The formation of covalent and hydrogen bonds among PTA, PDA, and Cur endowed the hydrogels with excellent self-healing and bioadhesion properties. These hydrogels were utilized as dressings for healing Staphylococcus aureus-infected wounds. The PDA-PTA-Cur 16 hydrogel showed the best overall performance in stability, bioadhesion, antioxidant activity, and antibacterial effectiveness. The in vivo results revealed that the PDA-PTA-Cur 16 hydrogel accelerated infected wound healing by inhibiting bacterial growth, alleviating inflammation, promoting collagen deposition, and inducing angiogenesis. This multifunctional hydrogel not only enhances wound healing but also presents a promising strategy for combating bacterial infections in clinical settings.

Multifaceted role of nanocomposite hydrogels in diabetic wound healing: enhanced biomedical applications and detailed molecular mechanisms

The complex microenvironment of diabetic wounds, which is characterized by persistent hyperglycemia, excessive inflammatory responses, and hypoxic conditions, significantly impedes the efficacy of traditional hydrogels. Nanocomposite hydrogels, which combine the high-water content and biocompatibility of hydrogels with the unique functionalities of nanomaterials, offer a promising solution. These hydrogels exhibit enhanced antibacterial, antioxidant, and drug-release properties. Incorporating nanomaterials increases the mechanical strength and bioactivity of hydrogels, allowing for dynamic regulation of the wound microenvironment and promoting cell migration, proliferation, and angiogenesis, thereby accelerating wound healing. This review provides a comprehensive overview of the latest advances in nanocomposite hydrogels for diabetic wound treatment and discusses their advantages and molecular mechanisms at various healing stages. The study aims to provide a theoretical foundation and practical guidance for future research and clinical applications. Furthermore, it highlights the challenges related to the mechanical durability, antimicrobial performance, resistance issues, and interactions with the cellular environments of these hydrogels. Future directions include optimizing smart drug delivery systems and personalized medical approaches to enhance the clinical applicability of nanocomposite hydrogels.

Involvement of macromolecules in 3D printing for wound healing management: A narrative review

Wound healing comprises four overlapping stages involving complex biochemical and cellular processes. Any lapse in this procedure causes irregular healing, which generates clinical and financial burdens for the health system. Personalized treatment is preferred to overcome the limitations of classical as well as modern methods of wound healing. This review discusses recently developed 3D printing models for personalized treatment with varying degrees of success. It is an effective approach for treating wounds by developing custom dressings tailored to the patient's needs and reducing incidents of infections. Additionally, incorporating natural or synthetic polymers can further enhance their effectiveness. Macromolecular polymers, laminin, cellulose, collagen, gelatin, etc. that make up the bulk of 3D printable bio-inks, have been essential in diverse 3D bioprinting technologies throughout the layered 3D manufacturing processes. The polymers need to be tailored for the specific requirements of printing and effector functions in cancer treatment, dental & oral care, biosensors, and muscle repair. We have explored how 3D printing can be utilized to fasten the process of wound healing at each of the four stages. The benefits as well as the future prospects are also discussed in this article.

Enhancing Wound Healing With Sprayable Hydrogel Releasing Multi Metallic Ions: Inspired by the Body's Endogenous Healing Mechanism

In the pursuit of new wound care products, researchers are exploring methods to improve wound healing through exogenous wound healing products. However, diverging from this conventional approach, this work has developed an endogenous support system for wound healing, drawing inspiration from the body's innate healing mechanisms governed by the sequential release of metal ions by body at wound site to promote different stages of wound healing. This work engineers a multi-ion-releasing sprayable hydrogel system, to mimic this intricate process, representing the next evolutionary step in wound care products. It comprises Alginate (Alg) and Fibrin (Fib) hydrogel infused with Polylactic acid (PLA) polymeric microcarriers encapsulating multi (calcium, copper, and zinc) nanoparticles (Alg-Fib-PLA-nCMB). Developed sprayable Alg-Fib-PLA-nCMB hydrogel show sustained release of beneficial multi metallic ions at wound site, offering a range of advantages including enhanced cellular function, antibacterial properties, and promotion of crucial wound healing processes like cell migration, ROS mitigation, macrophage polarization, collagen deposition, and vascular regeneration. In a comparative study with a commercial product (Midstress spray), developed Alg-Fib-PLA-nCMB hydrogel demonstrates superior wound healing outcomes in a rat model, indicating its potential for next generation wound care product, addressing critical challenges and offering a promising avenue for future advancements in the wound management.

Advancing burn wound treatment: exploring hydrogel as a transdermal drug delivery system

Burn injuries are prevalent and life-threatening forms that contribute significantly to mortality rates due to associated wound infections. The management of burn wounds presents substantial challenges. Hydrogel exhibits tremendous potential as an ideal alternative to traditional wound dressings such as gauze. This is primarily attributed to its three-dimensional (3D) crosslinked polymer network, which possesses a high water content, fostering a moist environment that supports effective burn wound healing. Additionally, hydrogel facilitates the penetration of loaded therapeutic agents throughout the wound surface, combating burn wound pathogens through the hydration effect and thereby enhancing the healing process. However, the presence of eschar formation on burn wounds obstructs the passive diffusion of therapeutics, impairing the efficacy of hydrogel as a wound dressing, particularly in cases of severe burns involving deeper tissue damage. This review focuses on exploring the potential of hydrogel as a carrier for transdermal drug delivery in burn wound treatment. Furthermore, strategies aimed at enhancing the transdermal delivery of therapeutic agents from hydrogel to optimize burn wound healing are also discussed.

Multifunctional carboxymethyl chitosan/oxidized carboxymethyl cellulose hydrogel loaded with ginsenoside Rg1 and polydopamine nanoparticles for infected diabetic wound healing

Besides bacterial infection, diabetic wounds are often accompanied by local inflammatory response, oxidative stress imbalances, and vascular formation disorders, which are the main reasons for long-term non-healing of diabetic wounds. In order to solve this problem, Ch-OCMC-PDA NPs-Rg1 self-healing hydrogel was constructed by Schiff base reaction. With the addition of PDA NPs and Rg1, Ch-OCMC-PDA NPs-Rg1 hydrogel showed excellent physical properties, like compressive strength of 142 kPa, swelling ratio of 148.91 %, and Rg1 carried in the hydrogel could achieve a slow release of 90.59 % within 48 h. What's more, PDA NPs endowed it with highly efficient photothermal antibacterial properties. In addition to excellent biocompatibility, Ch-OCMC-PDA NPs-Rg1 hydrogel could effectively clear intracellular reactive oxygen species, promote macrophages M2 transformation, and facilitate human umbilical vein endothelial cells migration and tube formation. In vivo experiments exhibited that Ch-OCMC-PDA NPs-Rg1 hydrogel could reduce wound inflammation, stimulate early angiogenesis, promote collagen deposition, and shorten the healing process of diabetic infected wounds, and the wound healing rate was significantly increased compared with other groups, reaching 98.41 ± 0.31 %. In summary, the multi-functional dynamic Ch-OCMC-PDA NPs-Rg1 hydrogel provides a new possibility for the treatment of diabetic infection wounds.

Latest advance anti-inflammatory hydrogel wound dressings and traditional Lignosus rhinoceros used for wound healing agents

Wound healing is a physiological process occurring after the onset of a skin lesion aiming to reconstruct the dermal barrier between the external environment and the body. Depending on the nature and duration of the healing process, wounds are classified as acute (e.g., trauma, surgical wounds) and chronic (e.g., diabetic ulcers) wounds. The latter, often affect millions of people globally, take months to heal or not heal non-healing chronic wounds, are typically susceptible to microbial infection, and are a major cause of morbidity. Wounds can be treated with a variety of non-surgical (topical formulations, wound dressings) and surgical (debridement, skin grafts/flaps) methods. Three-dimensional (3D)-(bio) printing and traditional wound dressings are two examples of modern experimental techniques. This review focuses on several types of anti-inflammatory wound dressings, especially focusing on hydrogels and traditional macro-fungi like L. rhinocerotis as agents that promote wound healing. In this study, we introduced novel anti-inflammatory hydrogel dressings and offered innovative methods for application and preparation to aid in the healing. Additionally, we summarize the key elements required for wound healing and discuss our analysis of potential future issues. These findings suggest that L. rhinocerotis and various anti-inflammatory hydrogels can be considered as conventional and alternative macro-fungi for the treatment of non-communicable diseases. We summarized the development of functional hydrogel dressings and traditional Lignosus rhinoceros used for wound healing agents in recent years, as well as the current situation and future trends, in light of their preparation mechanisms and functional effects.

Inflammation-Modulating Biomedical Interventions for Diabetic Wound Healing: An Overview of Preclinical and Clinical Studies

A diabetic wound exemplifies the challenge of chronic, nonhealing wounds. Elevated blood sugar levels in diabetes profoundly disrupt macrophage function, impairing crucial activities such as phagocytosis, immune response, cell migration, and blood vessel formation, all essential for effective wound healing. Moreover, the persistent presence of pro-inflammatory cytokines and reactive oxygen species, coupled with a decrease in anti-inflammatory factors, exacerbates the delay in wound healing associated with diabetes. This review emphasizes the dysfunctional inflammatory responses underlying diabetic wounds and explores preclinical studies of inflammation-modulating bioactives and biomaterials that show promise in expediting diabetic wound healing. Additionally, this review provides an overview of selected clinical studies employing biomaterials and bioactive molecules, shedding light on the gap between extensive preclinical research and limited clinical studies in this field.

Endogenous/exogenous stimuli‐responsive smart hydrogels for diabetic wound healing

Diabetes significantly impairs the body's wound‐healing capabilities, leading to chronic, infection‐prone wounds. These wounds are characterized by hyperglycemia, inflammation, hypoxia, variable pH levels, increased matrix metalloproteinase activity, oxidative stress, and bacterial colonization. These complex conditions complicate effective wound management, prompting the development of advanced diabetic wound care strategies that exploit specific wound characteristics such as acidic pH, high glucose levels, and oxidative stress to trigger controlled drug release, thereby enhancing the therapeutic effects of the dressings. Among the solutions, hydrogels emerge as promising due to their stimuli‐responsive nature, making them highly effective for managing these wounds. The latest advancements in mono/multi‐stimuli‐responsive smart hydrogels showcase their superiority and potential as healthcare materials, as highlighted by relevant case studies. However, traditional wound dressings fall short of meeting the nuanced needs of these wounds, such as adjustable adhesion, easy removal, real‐time wound status monitoring, and dynamic drug release adjustment according to the wound's specific conditions. Responsive hydrogels represent a significant leap forward as advanced dressings proficient in sensing and responding to the wound environment, offering a more targeted approach to diabetic wound treatment. This review highlights recent advancements in smart hydrogels for wound dressing, monitoring, and drug delivery, emphasizing their role in improving diabetic wound healing. It addresses ongoing challenges and future directions, aiming to guide their clinical adoption.

Effect of oxidized Bletilla striata polysaccharide on fibrin hydrogel formation and its application in wound healing dressing

Wound healing is influenced by various factors, including oxidative damage, bacterial infection, and inadequate angiogenesis, which collectively contribute to a protracted healing process. In this work, we designed innovative multifunctional hydrogels based on fibrin integrated with Bletilla striata polysaccharides (BSP) or oxidated Bletilla striata polysaccharides (OBSP) for use as wound dressings. The preliminary structure and bioactivity of BSP and OBSP were investigated. The effect of polysaccharides on the self-assembly process of fibrin hydrogels were also evaluated. BSP and OBSP significantly altered the initial fibrin fibrillogenesis and the ultimate structure of the fibrin network. Relative to pure fibrin hydrogel, the incorporation of BSP and OBSP enhanced water swelling and retention, and decelerated the degradation of hydrogels in PBS. Furthermore, BSP and OBSP augmented the antioxidant, antibacterial, and anti-inflammatory properties of fibrin hydrogels, with OBSP demonstrating superior performance in these aspects. Through the development of a murine wound model, it was observed that the wound healing efficacy of hydrogels incorporating BSP and OBSP surpassed that of the pure fibrin group. Notably, the hydrogel formulated with 25 mg/mL OBSP exhibited the most pronounced therapeutic effect, achieving a healing rate approaching 100 %. Consequently, fibrin-OBSP composite hydrogels demonstrate significant potential as wound dressings.

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.

Biowaste rice husk derived cellulosic hydrogel incorporating industrial cotton waste nonwoven for wound dressing

Bio-wastes are organic materials achieved through biological sources. The rice crop produces a substantial amount of biowaste in the form of rice husk, which is rich in cellulose. In this research, cellulose was extracted from rice husk by alkalization and bleaching process. The rice husk extracted cellulose was further used to develop cellulose hydrogel by using the sol-gel technique. The nonwoven fabric of industrial cotton waste was developed in three different GSM (50, 100, and 150). The nonwoven fabric was incorporated in the cellulose hydrogel having three different concentrations (1 %, 2 %, and 3 %) to develop the hydrogel non-woven cotton fabric composite for sustainable wound dressing applications. Moreover, prepared rice husk extracted cellulose hydrogel loaded with AgNO3 (0.5 %, 1 %, and 1.5 %) for achieving antibacterial characteristics. The Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to confirm the existence of cellulose hydrogel layers within the cotton nonwoven composite. The developed hydrogel S12 exhibited a maximum fluid absorbency of 1281.84 % with a tensile strength of 28.6 N and elongation of 40.96 %. The results show successful rice husk extracted cellulose hydrogel formation, exhibiting structural stability, excellent exudate absorbency and moisture management, antimicrobial efficacy, and sustainability.

Advances in DNA nanotechnology for chronic wound management: Innovative functional nucleic acid nanostructures for overcoming key challenges

Chronic wound management is affected by three primary challenges: bacterial infection, oxidative stress and inflammation, and impaired regenerative capacity. Conventional treatment methods typically fail to deliver optimal outcomes, thus highlighting the urgency to develop innovative materials that can address these issues and improve efficacy. Recent advances in DNA nanotechnology have garnered significant interest, particularly in the field of functional nucleic acid (FNA) nanomaterials, owing to their exceptional biocompatibility, programmability, and therapeutic potential. Among them, FNAs with unique nanostructures have garnered considerable attention. First, they inherit the biological properties of FNAs, including biocompatibility, reactive oxygen species (ROS)-scavenging capabilities, and modulation of cellular functions. Second, based on a precise design, these nanostructures exhibit superior physical properties, stability, and cellular uptake. Third, by leveraging the programmability of DNA strands, FNA nanostructures can be customized to accommodate therapeutic nucleic acids, peptides, and small-molecule drugs, thereby enabling a stable and controlled drug delivery system. These unique characteristics enable the use of FNA nanostructures to effectively address the major challenges in chronic wound management. This review focuses on various FNA nanostructures, including tetrahedral framework nucleic acids (tFNAs), DNA hydrogels, DNA origami, and rolling-circle amplification (RCA) DNA assembly. Additionally, a summary of recent advancements in their design and application for chronic wound management as well as insights for future research in this field are provided.

Polysaccharide-based chondroitin sulfate macromolecule loaded hydrogel/scaffolds in wound healing- A comprehensive review on possibilities, research gaps, and safety assessment

Wound healing is an intricate multifactorial process that may alter the extent of scarring left by the wound. A substantial portion of the global population is impacted by non-healing wounds, imposing significant financial burdens on the healthcare system. The conventional dosage forms fail to improve the condition, especially in the presence of other morbidities. Thus, there is a pressing requirement for a type of wound dressing that can safeguard the wound site and facilitate skin regeneration, ultimately expediting the healing process. In this context, Chondroitin sulfate (CS), a sulfated glycosaminoglycan material, is capable of hydrating tissues and further promoting the healing. Thus, this comprehensive review article delves into the recent advancement of CS-based hydrogel/scaffolds for wound healing management. The article initially summarizes the various physicochemical characteristics and sources of CS, followed by a brief understanding of the importance of hydrogel and CS in tissue regeneration processes. This is the first instance of such a comprehensive summarization of CS-based hydrogel/scaffolds in wound healing, focusing more on the mechanistic wound healing process, furnishing the recent innovations and toxicity profile. This contemporary review provides a profound acquaintance of strategies for contemporary challenges and future direction in CS-based hydrogel/scaffolds for wound healing.

Tannic acid-reinforced soy protein/oxidized tragacanth gum-based multifunctional hemostatic film for regulation of wound healing

With recent advances in the field of tissue engineering, composite films with biocompatibility, antimicrobial properties, and wound healing properties have gained potential applications in the field of wound dressings. In this research work, composite films of soy protein (S)/oxidized tragacanth gum (G) were successfully made using the solution casting process. The metal-organic framework containing curcumin (MOF) with concentrations of 5 and 10 wt% and tannic acid (TA) with concentrations of 6 and 12 wt% were entered into the polymer film. Surface morphology with scanning electron microscope (FE-SEM), thermal stability, mechanical properties, chemical structure, antioxidant, water absorption, cell viability, antibacterial activity, and biodegradability of the prepared films were investigated in laboratory conditions. In addition, the toxicity of the films in the cell environment was investigated, and the results showed that cell growth and proliferation improved in the presence of the prepared films, especially films SG/MOF10/TA6 and SG/MOF10/TA12 due to the presence of TA and MOF containing curcumin. Also, the antibacterial activity of the films showed that the presence of tannic acid and curcumin in the structure of the films increases their ability against pathogens. According to the obtained results, the newly produced nanocomposite film (SG/MOF10/TA12) has a high potential to be used for wound dressing due to its favorable characteristics and was considered the optimal film.

Nanofiber-reinforced chitosan/gelatine hydrogel with photothermal, antioxidant and conductive capabilities promotes healing of infected wounds

The wound healing process was often accompanied by bacterial infection and inflammation. The combination of electrically conductive nanomaterials and wound dressings could accelerate cell proliferation through endogenous electrical signaling, effectively promoting wound healing. In this study, polypyrrole was modified with dopamine hydrochloride by an in situ polymerization to form dopamine-polypyrrole (DA-Ppy) conductive nanofibers which successfully enhanced the water dispersibility and biocompatibility of polypyrrole. The DA-Ppy nanofibers were dispersed in an aqueous solution for >48 h and still maintained good stability. In addition, the DA-Ppy nanofibers showed good photothermal properties, and the temperature could reach 59.7 °C by 1.5 W/cm2 near-infrared light irradiation (NIR) for 10 min. DA-Ppy conductive nanofibres could be well dispersed in 3,4-dihydroxyphenylpropionic acid modified chitosan-carboxymethylated β-cyclodextrin modified gelatin (CG) hydrogel due to the presence of DA, which endowed CG/DA-Ppy hydrogel with good adhesion properties, and the hydrogel adhered to the pigskin would not be dislodged by washing with running water. Under NIR, the CG/DA-Ppy hydrogel showed significant antimicrobial properties. Moreover, the CG/DA-Ppy hydrogel had excellent biocompatibility. In addition, CG/DA-Ppy hydrogel was effective in scavenging ROS, inducing macrophage polarization towards the M2 phenotype, and modulating the level of wound inflammation in vitro. Finally, it was confirmed in rat-infected wounds that the tissue regeneration effect and collagen deposition in the CG/DA-Ppy + NIR group were significantly better than the other groups in the repair of infected wounds, indicating better repair of infected wounds. The results suggested that the photothermal, antioxidant DA-Ppy conductive nanofiber had great potential for application in infected wound healing.