Bioactive Anti-inflammatory, Antibacterial, Antioxidative Silicon-Based Nanofibrous Dressing Enables Cutaneous Tumor Photothermo-Chemo Therapy and Infection-Induced Wound Healing

Citric Acid: A Nexus Between Cellular Mechanisms and Biomaterial Innovations

Citrate-based biodegradable polymers have emerged as a distinctive biomaterial platform with tremendous potential for diverse medical applications. By harnessing their versatile chemistry, these polymers exhibit a wide range of material and bioactive properties, enabling them to regulate cell metabolism and stem cell differentiation through energy metabolism, metabonegenesis, angiogenesis, and immunomodulation. Moreover, the recent US Food and Drug Administration (FDA) clearance of the biodegradable poly(octamethylene citrate) (POC)/hydroxyapatite-based orthopedic fixation devices represents a translational research milestone for biomaterial science. POC joins a short list of biodegradable synthetic polymers that have ever been authorized by the FDA for use in humans. The clinical success of POC has sparked enthusiasm and accelerated the development of next-generation citrate-based biomaterials. This review presents a comprehensive, forward-thinking discussion on the pivotal role of citrate chemistry and metabolism in various tissue regeneration and on the development of functional citrate-based metabotissugenic biomaterials for regenerative engineering applications.

Obstructed vein delivery of ceftriaxone via poly(vinyl-pyrrolidone)-iodine-chitosan nanofibers for the management of diabetic foot infections and burn wounds

Superficial skin injuries especially burn injuries and unhealed diabetic foot open wounds remain troubling for public health. The healing process is often interrupted by the invasion of resistant pathogens that results in the failure of conventional procedures outside the clinical settings. Herein, we designed nanofibers dressing with intrinsic antibacterial potential of poly(vinyl-pyrrolidone)-iodine/ poly (vinyl)-alcohol by electrospinning with chitosan encapsulating ceftriaxone (CPC/NFs). The optimized electrospun CPC/NFs exhibited smooth surface morphology with average diameter of 165 ± 7.1 nm, drug entrapment and loading efficiencies of 76.97 ± 4.7 % and 8.32 ± 1.73 %, respectively. The results displayed smooth and uniformed fibers with adequate thermal stability and ensured chemical doping. The enhanced in vitro antibacterial efficacy of CPC/NFs against resistant E. coli isolates and biosafety studies encourage the use of designed nanofibers dressing for burn injuries and diabetic foot injuries. In vivo studies proved the healing power of dressing for burn wounds model and diabetic infected wounds model. Immunofluorescence investigation of the wound tissue also suggested promising healing ability of CPC/NFs. The designed approach would be helpful to treat these infected skin open wounds in the hospitals and outside the clinical settings.

Near-Infrared Responsive Nanocomposite Hydrogel Dressing with Anti-Inflammation and Pro-Angiogenesis for Wound Healing

Anti-inflammatory and angiogenesis are two important factors in wound healing. Wound dressings with anti-inflammation and vascularization are essential to address complex interventions, expensive treatments, and uncontrolled release mechanisms. Based on the above considerations, we designed a near-infrared (NIR)-responsive hydrogel dressing, which is composed of mPDA-DFO@LA nanoparticles (mPDA: dopamine hydrochloride nanoparticles, DFO: deferoxamine, LA: lauric acid), valsartan (abbreviated as Va), and dopamine-hyaluronic acid hydrogel. The hydrogel dressing demonstrated injectability, bioadhesive, and photothermal properties. The results indicated the obtained dressing by releasing Va can appropriately regulate macrophage phenotype transformation from M1 to M2, resulting in an anti-inflammatory environment. In addition, DFO encapsulated by LA can be sustainably released into the wound site by NIR irradiation, which further prevents excessive neovascularization. Notably, the results in vivo indicated the mPDA-DFO@LA/Va hydrogel dressing significantly enhanced wound recovery, achieving a healing rate of up to 96% after 11 days of treatment. Therefore, this NIR-responsive hydrogel dressing with anti-inflammation, vascularization, and on-demand programmed drug release will be a promising wound dressing for wound infection.

Robust Gradient Hydrogel-Loaded Nanofiber Fleshy Artificial Skin Via A Coupled Microfluidic Electrospinning-Reactive Coating Strategy

Skin regeneration attracts tremendous interest due to the important role of skin for human protection and beauty. Thus, methods allowing artificial skin to be carried out in a controllable fashion are potentially important for wound healing, which involves an intersection of materials, medicine, biology, and other disciplines. Herein, aiming at a new general methodology for fleshy materials, a new hydrogel-loaded hydrophobic-hydrophilic nanofiber fleshy artificial skin is designed and fabricated. The gradient hydrogel-loaded nanofiber artificial skin integrates both advantages of nanofiber and hydrogel, exhibiting fleshy feature (comparability to real skin in terms of appearance, texture, and function), excellent air permeability, compatibility, and good mechanical and antibacterial property. Interestingly, the efficient transport channels are formed throughout the hydrogel-loaded nanofiber structure, which is beneficial for water absorption and transfer. These advantages enable the establishment of a moist and favorable microenvironment; thus, greatly accelerating wound healing process. This work couples microfluidic electrospinning with reactive coating technique, which is in favor of material design and fabrication with controllable and uniform structures. The hydrogel-loaded nanofiber fleshy artificial skin shows comparability to real skin in terms of beauty, texture, and function, which would definitely provide new opportunities for the further optimization and upgrading of artificial skin.

A TLR4-Targeting Bioactive Peptide Hydrogel to Regulate Immune-Microenvironment for Diabetic Wound Repair

Persistent inflammation and disrupted immunoregulation are critical factors in impeding diabetic wound healing. While immunoregulatory hydrogel dressings hold significant promise for clinical applications in diabetic wound healing, the current application often demands intricate interventions and high-cost treatments involving cytokines and cell therapies. The development of single component immunoregulatory hydrogels remains a complex challenge. To address this issue, an active peptide hydrogel with immunoregulatory properties targeting the TLR4/NF-kB pathway, aiming to promote rapid diabetic wound healing, is engineered. The hydrogel sequence comprises naphthalene derivative, phenylalanine, and glycine to modulate hydrophilic/hydrophobic characteristics. The amino group on arginine contributes to tissue adhesion and regulation of intermolecular forces, ultimately yielding stable gels. The results underscore the formation of the peptide hydrogel (NFA) via the physical crosslinking of self-assembled nanofibers in water, thereby affording both excellent injectability and tissue adhesion. Notably, NFA demonstrates significant potential in promoting wound healing in a mouse model with full-thickness wounds by regulating macrophage responses in the inflammatory microenvironment through the TLR4/NF-kB pathway.

Injectable and Near-Infrared Light-Controllable Fibrin Hydrogels with Antimicrobial and Immunomodulating Properties for Infected Wound Healing

The management of infected wounds poses a significant challenge due to the growing issue of antibiotic resistance, underscoring the urgent necessity to innovate and implement alternative therapeutic strategies. These strategies should be capable of eliminating bacterial infections in infected wounds while circumventing the induction of multi-drug resistance. In the current study, we developed an easily prepared and injectable fibrin gel (FG) loaded with nanoparticles (NPs) that exhibit antibacterial and immunomodulatory properties to facilitate the healing of infected wounds. Initially, a novel type of NP was generated through the electrostatic interaction between the photothermal agent, mPEG-modified polydopamine (MPDA), and the nitric oxide (NO) donor, S-nitrosocysteamine (SNO). This interaction resulted in the formation of NPs referred to as SNO-loaded MPDA (SMPDA). Subsequently, the SMPDA was encapsulated into the FG using a double-barreled syringe, thereby producing the SMPDA-loaded FG (SMPDA/G). Experimental results revealed that SMPDA/G could effectively eliminate bacterial infections and alter the immune microenvironment. This efficacy is attributed to the synergistic combination of NO therapy and photothermal therapy, along with the role of SMPDA in facilitating M2 macrophage polarization within the gel. Accordingly, these findings suggest that the SMPDA/G holds substantial promise for clinical application in infected wound healing.

Recent advances in reactive oxygen species scavenging nanomaterials for wound healing

Reactive oxygen species play a crucial role in cell signaling pathways during wound healing phases. Treatment strategies to balance the redox level in the deep wound tissue are emerging for wound management. In recent years, reactive oxygen species scavenging agents including natural antioxidants, reactive oxygen species (ROS) scavenging nanozymes, and antioxidant delivery systems have been widely employed to inhibit oxidative stress and promote skin regeneration. Here, the importance of reactive oxygen species in different wound healing phases is critically analyzed. Various cutting-edge bioactive ROS nanoscavengers and antioxidant delivery platforms are discussed. This review also highlights the future directions for wound therapies via reactive oxygen species scavenging. This comprehensive review offers a map of the research on ROS scavengers with redox balancing mechanisms of action in the wound healing process, which benefits development and clinical applications of next-generation ROS scavenging-based nanomaterials in skin regeneration.

A bismuth-based double-network hydrogel-mediated synergistic photothermal-chemodynamic therapy for accelerated wound healing

Multidrug-resistant bacterial infections present a significant challenge to wound healing. Non-antibiotic approaches such as photothermal therapy (PTT) and chemodynamic therapy (CDT) are promising but have suboptimal anti-bacterial efficacy. Herein, we developed a green bismuth-based double-network hydrogel (Bi@P-Cu) as a PTT/CDT synergistic platform for accelerated drug-resistant bacteria-infected wound healing. Bismuth (Bi) nanoparticles fabricated using a microwave method were used as a highly efficient and biocompatible PTT agent while the integration of a small amount of CDT agent Cu2+ endowed the hydrogel with excellent mechanical and self-healing properties, markedly increased photothermal efficiency, promoted cell migration ability, and negligible toxicity. Importantly, PTT enhanced the production of hydroxyl radicals in CDT and the destruction of bacterial cell membranes, which in turn enhanced the thermal sensitivity of bacteria. This synergistic anti-bacterial effect, together with the demonstrated capability to promote angiogenesis and anti-inflammation as well as enhanced fibroblast proliferation, led to accelerated wound healing in a full-thickness mouse model of resistant bacterial infection. This study provides an effective and safe strategy to eliminate drug-resistant bacteria and accelerate wound healing through green, non-antibiotic, double-network hydrogel-mediated synergistic PTT and CDT.

Versatile Antibacterial and Antioxidant Bacterial Cellulose@Nanoceria Biotextile: Application in Reusable Antimicrobial Face Masks

Despite considerable interest in medical and pharmaceutical fields, there remains a notable absence of functional textiles that concurrently exhibit antibacterial and antioxidant properties. Herein, a new composite fabric constructed using nanostructured bacterial cellulose (BC) covalently-linked with cerium oxide nanoparticles (BC@CeO2NPs) is introduced. The synthesis of CeO2NPs on the BC is performed via a microwave-assisted, in situ chemical deposition technique, resulting in the formation of mixed valence Ce3+/Ce4+ CeO2NPs. This approach ensures the durability of the composite fabric subjected to multiple washing cycles. The Reactive oxygen species (ROS) scavenging activity of CeO2NPs and their rapid and efficient eradication of >99% model microbes, such as Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus remain unaltered in the composite. To demonstrate the feasibility of incorporating the fabric in marketable products, antimicrobial face masks are fabricated with filter layers made of BC@CeO2NPs cross-linked with propylene or cotton fibers. These masks exhibit complete inhibition of bacterial growth in the three bacterial strains, improved breathability compared to respirator masks and enhanced filtration efficiency compared to single-use surgical face masks. This study provides valuable insights into the development of functional BC@CeO2NPs biotextiles in which design can be extended to the fabrication of medical dressings and cosmetic products with combined antibiotic, antioxidant and anti-inflammatory activities.

Marine polysaccharides: Biological activities and applications in drug delivery systems

The ocean is the common home of a large number of marine organisms, including plants, animals, and microorganisms. Researchers can extract thousands of important bioactive components from the oceans and use them extensively to treat and prevent diseases. In contrast, marine polysaccharide macromolecules such as alginate, carrageenan, Laminarin, fucoidan, chitosan, and hyaluronic acid have excellent physicochemical properties, good biocompatibility, and high bioactivity, which ensures their wide applications and strong therapeutic potentials in drug delivery. Drug delivery systems (DDS) based on marine polysaccharides and modified marine polysaccharide molecules have emerged as an innovative technology for controlling drug distribution on temporal, spatial, and dosage scales. They can detect and respond to external stimuli such as pH, temperature, and electric fields. These properties have led to their wide application in the design of novel drug delivery systems such as hydrogels, polymeric micelles, liposomes, microneedles, microspheres, etc. In addition, marine polysaccharide-based DDS not only have smart response properties but also can combine with the unique biological properties of the marine polysaccharide base to exert synergistic therapeutic effects. The biological activities of marine polysaccharides and the design of marine polysaccharide-based DDS are reviewed. Marine polysaccharide-based responsive DDS are expected to provide new strategies and solutions for disease treatment.

Double-layered microneedle patch loaded with bioinspired nano-vaccine for melanoma treatment and wound healing

Malignant melanoma is a challenging problem worldwide, because the remaining tumor cells and extensive skin defects following surgical resection are difficult to treat. Biomaterial-mediated immunotherapy has emerged as a superior strategy for anti-tumor applications in recent years. Herein, a unique double-layer MNP was developed to address the problem of malignant melanoma. Hydroxyapatite (HAP) and short-chain peptides from tumor cells were self-assembled to prepare the bioinspired nano-vaccine, and then they were loaded onto the microneedle tips of methacrylated gelatin (GelMA)-based MNP. The products (dubbed HVMN) demonstrated relatively good biocompatibility and immune activity, inhibiting the proliferation and inducing apoptosis of malignant melanoma in a B16 cell-bearing model of C57BL/6 mice, and promoting skin tissue regeneration in a full thickness skin defect model of SD rats in 15 days. The putative molecular pathways were examined preliminarily. In conclusion, this research will develop a competitive microneedle patch with dual anti-tumor and pro-regenerative properties for the postoperative treatment of malignant melanoma.

Photopolymerized multifunctional sodium alginate-based hydrogel for antibacterial and coagulation dressings

Trauma caused by tissue damage in clinical applications has posed a serious threat to public safety. Dressings with a single function cannot meet the needs of wound healing, but multifunctional dressings are difficult to achieve and obtain. To address this issue, this research designed a facile one-pot photo-crosslinking method to prepare multifunctional sodium alginate-based hydrogel dressings for effective wound healing. According to irregular wounds, sodium alginate-based hydrogel dressings can be quickly prepared anytime and anywhere. The structure and physicochemical properties of hydrogels are regulated by modulating the proportion of main components sodium alginate and acrylamide. The results showed the sodium alginate-based composite hydrogel as a candidate multifunctional dressing that exhibits excellent stretchability and compressibility, viscoelasticity, and suitable tissue-like adhesion. In vitro drug release and antibacterial experiments indicated that the hydrogel has effective antibacterial properties against S. aureus and P. aeruginosa. Furthermore, the haemostatic behaviour of the hydrogel was demonstrated using the coagulation activation test, whole blood-clotting test, and blood cell and platelet adhesion experiments. All these results demonstrated that the sodium alginate-based hydrogel had high application potential as a multifunctional medical dressing for wound healing.

Thermo-sensitive hydroxybutyl chitosan/diatom biosilica hydrogel with immune microenvironment regulatory for chronic wound healing

This study proposes a chronic wound therapeutic strategy based on extracellular matrix (ECM) biomimetics and immune regulation. The hydroxybutyl chitosan/diatom biosilica hydrogel (H/D) which can regulate the immune microenvironment, is prepared from hydroxybutyl chitosan (HBC) as matrix to construct the bionic ECM and diatom biosilica (DB) as structural active unit. The hierarchical porous structure of DB provides strong anchoring interface effect to enhance the mechanical strength of hydrogel, while maintaining its favorable temperature phase transition behavior, improving the material's fit to the wound and convenience of clinical use. Silicates released from DB in H/D accelerate the transition of wounds from inflammation to proliferation and remodeling. In cellular and diabetic rat models, H/D reduces inflammation (induces conversion of M1-type macrophages to M2-type), induces angiogenesis (1.96-fold of control), promotes fibroblast proliferation (180.36 % of control), collagen deposition, keratinocyte migration (47.34 % more than control), and re-epithelialization. This study validates a possible biological mechanism for H/D bioactive hydrogel-mediated regulation of the immune microenvironment and provides a simple synergistic dressing strategy.

Multifunctional Therapeutic Nanodiamond Hydrogels for Infected-Wound Healing and Cancer Therapy

Wound infection and tumor recurrence are the two main threats to cancer patients after surgery. Although researchers have developed new treatment systems to address the two significant challenges simultaneously, the potential side effects of the heavy-metal-ion-based treatment systems still severely limit their widespread application in therapy. In addition, the wounds from tumor removal compared with general operative wounds are more complex. The tumor wounds mainly exhibit more hemorrhage, larger trauma area, greater vulnerability to bacterial infection, and residual tumor cells. Therefore, a multifunctional treatment platform is urgently needed to integrate rapid hemostasis, sterilization, wound healing promotion, and antitumor functions. In this work, nanodiamonds (NDs), a material that has been well proven to have excellent biocompatibility, are added into a solution of acrylic-grafted chitosan (CEC) and oxidized hyaluronic acid (OHA) to construct a multifunctional treatment platform (CEC-OHA-NDs). The hydrogels exhibit rapid hemostasis, a wound-healing-promoting effect, excellent self-healing, and injectable abilities. Moreover, CEC-OHA-NDs can effectively eliminate bacteria and inhibit tumor proliferation by the warm photothermal effect of NDs under tissue-penetrable near-infrared laser irradiation (NIR) without cytotoxicity. Consequently, we adopt a simple and convenient strategy to construct a multifunctional treatment platform using carbon-based nanomaterials with excellent biocompatibility to promote the healing of infected wounds and to inhibit tumor cell proliferation simultaneously.

Injectable hydrogel with antimicrobial and anti-inflammatory properties for postoperative tumor wound care

Clinically, tumor removal surgery leaves irregularly shaped wounds that are susceptible to bacterial infection and further lead to excessive inflammation. Injectable hydrogel dressings with antimicrobial and anti-inflammatory properties have been recognized as an effective strategy to care for postoperative tumor wounds and prevent recurrence in recent years. In this work, we constructed a hydrogel network by ionic bonding interactions between quaternized chitosan (QCS) and epigallocatechin gallate (EGCG)-Zn complexes which were coordinated by EGCG and zinc ions. Because of the synergistic effect of QCS and EGCG-Zn, the hydrogel exhibited outstanding antimicrobial capacity (>99.9% inhibition), which could prevent infections caused byEscherichia coli and Staphylococcus aureus. In addition, the hydrogel was able to inhibit the growth of mice breast cancer cells (56.81% survival rate within 72 h) and reduce inflammation, which was attributed to the sustained release of EGCG. The results showed that the hydrogel was effective in inhibiting tumor recurrence and accelerating wound closure when applied to the postoperative tumor wounds. This study provided a simple and reliable strategy for postoperative tumor wound care using antimicrobial and anti-inflammatory injectable dressings, confirming their great potential in the field of postoperative wound dressings.

An injectable nanocomposite hydrogel prevents postoperative tumor recurrence and wound infection via synergistic photothermal-chemo-therapy

HYPOTHESIS

Tumor recurrence, bacterial infection, and wound healing remain significant clinical challenges after skin-tumor resection. In this study, we tested the hypothesis that a multifunctional nanocomposite platform containing nanoparticles (NPs) with the photothermal agent IR820 and bioactive drug curcumin (Cur) would be able to prevent tumor recurrence, limit bacterial wound infections, and promote wound healing.

EXPERIMENTS

In this study, we developed a near-infrared light-activated nanocomposite hydrogel system (Hydrogel/Cur@IR820) by incorporating self-assembled NPs (Cur@IR820) in solutions containing Pluronic F127 modified with aldehyde groups (F127-CHO) and polyethyleneimine-grafted F127 (F127-PEI).

FINDINGS

The Hydrogel/Cur@IR820 platform exhibited inherent multifunctional properties, including superior injectability, self-healing behavior, photothermal effects, and free radical scavenging ability. The Cur@IR820 NPs led to photonic hyperthermia and near-infrared (NIR)-triggered Cur release, which drove synergistic therapeutic effects against bacteria and tumor cells. Furthermore, the Hydrogel/Cur@IR820 system promoted wound repair and tissue regeneration by reducing inflammation through the antioxidant properties of Cur. Overall, the results of this study have clinical implications for inhibiting tumor growth, treating bacterial infections, and accelerating tissue regeneration.

Antimicrobial, Antioxidant, and Anti-Inflammatory Nanoplatform for Effective Management of Infected Wounds

Burn wound healing continues to pose significant challenges due to excessive inflammation, the risk of infection, and impaired tissue regeneration. In this regard, an antibacterial, antioxidant, and anti-inflammatory nanocomposite (called HPA) that combines a nanosystem using hexachlorocyclotriphosphazene and the natural polyphenol of Phloretin with silver nanoparticles (AgNPs) is developed. HPA effectively disperses AgNPs to mitigate any toxicity caused by aggregation while also showing the pharmacological activities of Phloretin. During the initial stage of wound healing, HPA rapidly releases silver ions from its surface to suppress bacterial activity. Moreover, these nanoparticles are pH-sensitive and degrade efficiently in the acidic infection microenvironment, gradually releasing Phloretin. This sustained release of Phloretin helps scavenge overexpressed reactive oxygen species in the infected microenvironment area, thus reducing the upregulation of pro-inflammatory cytokines. The antibacterial activity, free radical clearance, and regulation of inflammatory factors of HPA through in vitro experiments are validated. Additionally, its effects using an infectious burn mouse model in vivo are evaluated. HPA is found to promote collagen deposition and epithelialization in the wound area. With its synergistic antibacterial, antioxidant, and anti-inflammatory activities, as well as favorable biocompatibilities, HPA shows great promise as a safe and effective multifunctional nanoplatform for burn injury wound dressings.

Enabling Proregenerative Medical Devices via Citrate-Based Biomaterials: Transitioning from Inert to Regenerative Biomaterials

Regenerative medicine aims to restore tissue and organ function without the use of prosthetics and permanent implants. However, achieving this goal has been elusive, and the field remains mostly an academic discipline with few products widely used in clinical practice. From a materials science perspective, barriers include the lack of proregenerative biomaterials, a complex regulatory process to demonstrate safety and efficacy, and user adoption challenges. Although biomaterials, particularly biodegradable polymers, can play a major role in regenerative medicine, their suboptimal mechanical and degradation properties often limit their use, and they do not support inherent biological processes that facilitate tissue regeneration. As of 2020, nine synthetic biodegradable polymers used in medical devices are cleared or approved for use in the United States of America. Despite the limitations in the design, production, and marketing of these devices, this small number of biodegradable polymers has dominated the resorbable medical device market for the past 50 years. This perspective will review the history and applications of biodegradable polymers used in medical devices, highlight the need and requirements for regenerative biomaterials, and discuss the path behind the recent successful introduction of citrate-based biomaterials for manufacturing innovative medical products aimed at improving the outcome of musculoskeletal surgeries.

Functional electrospun nanofibers: fabrication, properties, and applications in wound-healing process

Electrostatic spinning as a technique for producing nanoscale fibers has recently attracted increasing attention due to its simplicity, versatility, and loadability. Nanofibers prepared by electrostatic spinning have been widely studied, especially in biomedical applications, because of their high specific surface area, high porosity, easy size control, and easy surface functionalization. Wound healing is a highly complex and dynamic process that is a crucial step in the body's healing process to recover from tissue injury or other forms of damage. Single-component nanofibers are more or less limited in terms of structural properties and do not fully satisfy various needs of the materials. This review aims to provide an in-depth analysis of the literature on the use of electrostatically spun nanofibers to promote wound healing, to overview the infinite possibilities for researchers to tap into their biomedical applications through functional composite modification of nanofibers for advanced and multifunctional materials, and to propose directions and perspectives for future research.

Engineering Single-Component Antibacterial Anti-inflammatory Polyitaconate-Based Hydrogel for Promoting Methicillin-Resistant Staphylococcus aureus-Infected Wound Healing and Skin Regeneration

Hydrogel wound dressings play a crucial role in promoting the healing of drug-resistant bacterially infected wounds. However, their clinical application often faces challenges such as the use of numerous components, a complicated preparation process, and insufficient biological activity. Itaconic acid, known for its excellent biological and reaction activities, has not been extensively studied for the preparation of itaconic acid-based hydrogels and their application in infected wound healing. Therefore, there is a need to develop a multifunctional single-component itaconic acid-based hydrogel that is easy to synthesize and holds promising prospects for clinical use in promoting the healing of infected wounds. In this study, we present a single-component polyitaconate-based hydrogel (PICGI) with antibacterial, anti-inflammatory, and biological activity. The PICGI hydrogel demonstrates great potential in promoting healing of infected wounds and skin regeneration. It exhibits desirable thermosensitive, injectable, and adhesive properties, as well as broad-spectrum antibacterial activity and anti-inflammatory effects. Furthermore, the PICGI hydrogel is biocompatible and significantly enhances the migration and tube formation of endothelial cells. In the case of drug-resistant bacterially infected wounds, the PICGI hydrogel effectively inhibits bacterial infection and inflammation, promotes angiogenesis, and facilitates collagen deposition, thereby accelerating the healing and regeneration of the skin. This study highlights the promising application of the PICGI hydrogel as a single-component hydrogel in tissue repair associated with bacterial infection and inflammation. Moreover, the simplicity of its components, convenient preparation process, and sufficient biological activity make the PICGI hydrogel highly suitable for promotion and clinical application.

Multifunctional Hydrogels for the Healing of Diabetic Wounds

The healing of diabetic wounds is hindered by various factors, including bacterial infection, macrophage dysfunction, excess proinflammatory cytokines, high levels of reactive oxygen species, and sustained hypoxia. These factors collectively impede cellular behaviors and the healing process. Consequently, this review presents intelligent hydrogels equipped with multifunctional capacities, which enable them to dynamically respond to the microenvironment and accelerate wound healing in various ways, including stimuli -responsiveness, injectable self-healing, shape -memory, and conductive and real-time monitoring properties. The relationship between the multiple functions and wound healing is also discussed. Based on the microenvironment of diabetic wounds, antibacterial, anti-inflammatory, immunomodulatory, antioxidant, and pro-angiogenic strategies are combined with multifunctional hydrogels. The application of multifunctional hydrogels in the repair of diabetic wounds is systematically discussed, aiming to provide guidelines for fabricating hydrogels for diabetic wound healing and exploring the role of intelligent hydrogels in the therapeutic processes.

Dual-crosslinked methacrylamide chitosan/poly(ε-caprolactone) nanofibers sequential releasing of tannic acid and curcumin drugs for accelerating wound healing

The objective of this research study is to develop novel composite nanofibers based on methacrylamide chitosan (ChMA)/poly(ε-caprolactone) (PCL) materials by the dual crosslinking and coaxial-electrospinning strategies. The prepared ChMA/PCL composite nanofibers can sequentially deliver tannic acid and curcumin drugs to synergistically inhibit bacterial reproduction and accelerate wound healing. The rapid delivery of tannic acid is expected to inhibit pathogenic microorganisms and accelerate epithelialization in the early stage, while the slow and sustained release of curcumin is with the aim of relieving chronic inflammatory response and inducing dermal tissue maturation in the late stage. Meanwhile, dual-drugs sequentially released from the membrane exhibited a DPPH free radical scavenging rate of ca. 95 % and an antibacterial rate of above 85 %. Moreover, the membrane possessed great biocompatibility in vitro and significantly inhibited the release of pro-inflammatory factors (IL-1β and TNF-α) in vivo. Animal experiments showed that the composite membrane by means of the synergistic effect of polyphenol drugs and ChMA nanofibers, could significantly alleviate macrophage infiltration and accelerate the healing process of wounds. From the above, the as-prepared ChMA-based membrane with a stage-wise release pattern of drugs could be a promising bioengineered construct for wound healing application.

Photothermal synergistic nitric oxide controlled release injectable self-healing adhesive hydrogel for biofilm eradication and wound healing

The development of injectable self-healing adhesive hydrogel dressings with excellent bactericidal activity and wound healing ability is urgently in demand for combating biofilm infections. Herein, a multifunctional hydrogel (QP/QT-MB) with near-infrared (NIR) light-activated mild photothermal/gaseous antimicrobial activity was developed based on the dynamic reversible borate bonds and hydrogen bonds crosslinking between quaternization chitosan (QCS) derivatives alternatively containing phenylboronic acid and catechol-like moieties in conjunction with the in situ encapsulation of BNN6-loaded mesoporous polydopamine (MPDA@BNN6 NPs). Given the dynamic reversible cross-linking feature, the versatile hybrid hydrogel exhibited injectability, flexibility, and rapid self-healing ability. The numerous phenylboronic acid and catechol-like moieties on the QCS backbone confer the hydrogel with specific bacterial affinity, desirable tissue adhesion, and antioxidant stress ability that enhance bactericidal activity and facilitate the regeneration of infection wounds. Under NIR irradiation, the QP/QT-MB hydrogels exhibited a desirable mild photothermal effect and NIR-activity controllable NO delivery, combined with the endogenous contact antimicrobial activity of hydrogel, contributing jointly to induce dispersal of biofilms and disruption of the bacterial plasma membranes, ultimately leading to bacteria inactivation and biofilm elimination. In vivo experiments demonstrated that the fabricated QP/QT-MB hydrogel platform was capable of inducing efficient eradication of the S. aureus biofilm in a severely infected wound model and accelerating infected wound repair by promoting collagen deposition, angiogenesis, and suppressing inflammatory responses. Additionally, the QP/QT-MB hydrogel demonstrated excellent biocompatibility in vitro and in vivo. Collectively, the hydrogel (QP/QT-MB) reveals great potential application prospects as a promising alternative in the field of biofilm-associated infection treatment.

Multifunctional Nanofibrous Scaffolds Capable of Localized Delivery of Theranostic Nanoparticles for Postoperative Cancer Management

Postoperative recovery of cancer patients can be affected by complications, such as tissue dysfunction or disability caused by tissue resection, and also cancer recurrence resulting from residual cancer cells. Despite impressive progress made for tissue engineering scaffolds that assist tissue regeneration for postoperative cancer patients, the majority of existing tissue engineering scaffolds still lack functions for monitoring and killing residual cancer cells, if there are any, upon their detection. In this study, multifunctional scaffolds that comprise biodegradable nanofibers and core-shell structured microspheres encapsulated with theranostic nanoparticles (NPs) are developed. The multifunctional scaffolds possess an extracellular matrix-like nanofibrous architecture and soft tissue-like mechanical properties, making them excellent tissue engineering patch candidates for assisting in the repair and regeneration of tissues at the cancerous sites after surgery. Furthermore, they are capable of localized delivery of theranostic NPs upon quick degradation of core-shell structured microspheres that contain theranostic NPs. Leveraging on folic acid-mediated ligand-receptor binding, surface-enhanced Raman scattering activity, and near-infrared-responsive photothermal effect of the theranostic gold NPs (AuNPs) delivered locally, the multifunctional scaffolds display excellent active targeting, diagnosis, and photothermal therapy functions for cancer cells, showing great promise for adaptive postoperative cancer management.

A multifunctional chitosan composite aerogel based on high density amidation for chronic wound healing

The management of chronic wounds remains a challenging clinical problem worldwide, mainly because of secondary infections, excessive oxidative stress, and blocked angiogenesis. Aerogel is a novel material with high porosity and specific surface area that allows gas exchange and rapid absorption of a large amount of exudate as well as loading bioactive molecules. Therefore, functional aerogel can be an ideal material for chronic wound treatment. The multifunctional aerogel (CG-DA-VEGF) was prepared by a simple and eco-friendly freeze-drying process combined with harmless EDC/NHS as crosslinking agents using chitosan and dopamine-grafted gelatin as raw materials. The physicochemical characterization revealed that the CG-DA-VEGF aerogel had excellent water absorption, water retention, and mechanical properties, and could release VEGF continuously and stably. In vitro experiments demonstrated that the CG-DA-VEGF aerogel exhibited effective antioxidant and antibacterial properties, as well as superb cytocompatibility. In vivo experiments further confirmed that the CG-DA-VEGF aerogel could significantly improve angiogenesis and re-epithelialization, and promote collagen deposition, thus accelerating wound healing with excellent biosafety. These results suggest that the as-prepared CG-DA-VEGF aerogel may be adopted as a promising multifunctional graft for the treatment of chronic wounds.

A multifunctional hydrogel dressing with high tensile and adhesive strength for infected skin wound healing in joint regions

Most hydrogel dressings are designed for skin wounds in flat areas, and few are focused on the joint skin regions which undergo frequent movement. The mismatch of mechanical properties and poor fit between a hydrogel dressing and a wound in joint skin results in hydrogel shedding, bacterial infection and delayed healing. Therefore, it is of great significance to design and prepare a multifunctional hydrogel with high tensile and tissue-adhesive strength as well as other therapeutic effects for the treatment of joint skin wounds. In this work, a multifunctional hydrogel was reasonably prepared by simply mixing polyvinyl alcohol (PVA), borax, tannic acid (TA) and iron(III) chloride in certain proportions, which was further used to treat the skin wounds at the joint of the hind limb. Acting as the physical crosslinkers, borax and TA dynamically bond with PVA and provide the resulting hydrogel with strong tensile, fast shape-adaptive and self-healing properties. The photothermal bacteriostatic activity of the hydrogel is attributed to the formation of a metallic polyphenol network (MPN) between ferric ions and TA. In addition, the hydrogel exhibits high levels of adhesion, hemostatic performance, antioxidant abilities, and biocompatibility, and shows great potential to promote joint skin wound healing.

Mussel-inspired "plug-and-play" hydrogel glue for postoperative tumor recurrence and wound infection inhibition

Currently, clinical tumor resection is faced with two options: open and minimally invasive surgery. Open surgery is easy to completely remove the lesion but is prone to infection, while minimally invasive surgery recovers faster but may cause tumor recurrence. To fill the shortcomings of the two surgical modes and make the choice for tumor resection more effortlessly, we developed a postoperative black phosphorus-Ag nanocomposites-loaded dopamine-modified hyaluronic acid-Pluronic® F127 (BP-Ag@HA-DA-Plu) hydrogel implantation system that can prevent tumor recurrence and wound infection simultaneously. Experiments have shown that the hydrogel system combined with 808 nm near-infrared (NIR) irradiation has excellent anti-tumor, antibacterial, and wound healing abilities. Additionally, unlike existing surgical hydrogel products that require inconvenient in-situ cross-linking, the BP-Ag@HA-DA-Plu hydrogel system offers "plug-and-play" functionality during surgery due to its thermo-responsiveness, injectability, and adhesion, thereby greatly improving the efficiency of surgery.

Janus polyurethane sponge as an antibiofouling, antibacterial, and exudate-managing dressing for accelerated wound healing

The non-fouling condition, bacteria-free environment and suitable moisture at wound site are crucial for chronic wound healing. However, it remains highly meaningful yet challenging to develop wound dressings that can simultaneously achieve these desirable functions. In this work, a kind of multifunctional Janus polyurethane sponge (Janus-PU) was designed and fabricated by coating near-infrared (NIR)-responsive and superhydrophobic nanoparticles (F-ZnO@Ag NPs) on one surface of sponge. The nano-functionalized outer layer can endow Janus-PU with superhydrophobic antifouling property for preventing bacterial colonization and broad-spectrum antibacterial activity due to the presence of Ag NPs. Especially, the synergistic combination of asymmetric structure and strong NIR photothermal effect can impart Janus-PU with NIR-controlled unidirectional exudate removal, thus achieving an optimal wetting environment for wound healing. The mice full-thickness skin acute wounds treated with Janus-PU under NIR irradiation showed superior anti-infection and healing effect compared to the commercial dressings. Significantly, the treatment using Janus-PU with NIR irradiation can accelerate the recovery of methicillin-resistant Staphylococcus aureus (MRSA)-infected diabetic chronic wounds due to the synergistic effect of antibiofouling, antibacterial and exudate-managing. The Janus-PU as a promising multifunctional dressing can prevent bacterial invasion and create an appropriate environment for wound healing, providing an effective solution for intractable wounds and infections. STATEMENT OF SIGNIFICANCE: The development of advanced wound dressings to ensure non-fouling condition, bacteria-free environment and suitable moisture is crucial for chronic wound healing. However, it remains a considerable challenge to simultaneously integrate antibiofouling, antibacterial and exudate-managing properties into a single dressing. In this work, we developed a kind of multifunctional Janus polyurethane sponge (Janus-PU) by a single-sided superhydrophobic modification strategy, which can simultaneously achieve superhydrophobic antifouling property, effective broad-spectrum antibacterial and near-infrared controlled exudate removal. The Janus-PU designed herein can not only create an optimal environment for accelerated wound healing, but also avoid frequent dressing replacement, thus providing an ideal material system for intractable wounds and infections.

Phase Change Material-Embedded Multifunctional Janus Nanofiber Dressing with Directional Moisture Transport, Controlled Release of Anti-Inflammatory Drugs, and Synergistic Antibacterial Properties

Wound healing is a systematic and complex process that involves various intrinsic and extrinsic factors affecting different stages of wound repair. Therefore, multifunctional wound dressings that can modulate these factors to promote wound healing are in high demand. In this work, a multifunctional Janus electrospinning nanofiber dressing with antibacterial and anti-inflammatory properties, controlled release of drugs, and unidirectional water transport was prepared by depositing coaxial nanofibers on a hydrophilic poly(ε-caprolactone)@polydopamine-ε-polyl-lysine (PCL@PDA-ε-PL) nanofiber membrane. The coaxial nanofiber was loaded with the phase change material lauric acid (LA) in the shell layer and anti-inflammatory ibuprofen (IBU) in the core layer. Among them, LA with a melting point of 43 °C served as a phase change material to control the release of IBU. The phase transition of LA was induced by near-infrared (NIR) irradiation that triggered the photothermal properties of PDA. Moreover, the Janus nanofiber dressing exhibited synergistic antimicrobial properties for Escherichia coli and Staphylococcus aureus due to the photothermal properties of PDA and antibacterial ε-PL. The prepared Janus nanofiber dressing also exhibited anti-inflammatory activity and biocompatibility. In addition, the Janus nanofiber dressing had asymmetric wettability that enabled directional water transport, thereby draining excessive wound exudate. The water vapor transmission test indicated that the Janus nanofiber dressing had good air permeability. Finally, skin wound healing evaluation in rats confirmed its efficacy in promoting wound healing. Therefore, this strategy of designing and manufacturing a multifunctional Janus nanofiber dressing had great potential in wound healing applications.

Photothermal antibacterial materials to promote wound healing

Wound healing is a crucial process that restores the integrity and function of the skin and other tissues after injury. However, external factors, such as infection and inflammation, can impair wound healing and cause severe tissue damage. Therefore, developing new drugs or methods to promote wound healing is of great significance. Photothermal therapy (PTT) is a promising technique that uses photothermal agents (PTAs) to convert near-infrared radiation into heat, which can eliminate bacteria and stimulate tissue regeneration. PTT has the advantages of high efficiency, controllability, and low drug resistance. Hence, nanomaterial-based PTT and its related strategies have been widely explored for wound healing applications. However, a comprehensive review of PTT-related strategies for wound healing is still lacking. In this review, we introduce the physiological mechanisms and influencing factors of wound healing, and summarize the types of PTAs commonly used for wound healing. Then, we discuss the strategies for designing nanocomposites for multimodal combination treatment of wounds. Moreover, we review methods to improve the therapeutic efficacy of PTT for wound healing, such as selecting the appropriate wound dressing form, controlling drug release, and changing the infrared irradiation window. Finally, we address the challenges of PTT in wound healing and suggest future directions.

Reactive X (where X = O, N, S, C, Cl, Br, and I) species nanomedicine

Reactive oxygen, nitrogen, sulfur, carbonyl, chlorine, bromine, and iodine species (RXS, where X = O, N, S, C, Cl, Br, and I) have important roles in various normal physiological processes and act as essential regulators of cell metabolism; their inherent biological activities govern cell signaling, immune balance, and tissue homeostasis. However, an imbalance between RXS production and consumption will induce the occurrence and development of various diseases. Due to the considerable progress of nanomedicine, a variety of nanosystems that can regulate RXS has been rationally designed and engineered for restoring RXS balance to halt the pathological processes of different diseases. The invention of radical-regulating nanomaterials creates the possibility of intriguing projects for disease treatment and promotes advances in nanomedicine. In this comprehensive review, we summarize, discuss, and highlight very-recent advances in RXS-based nanomedicine for versatile disease treatments. This review particularly focuses on the types and pathological effects of these reactive species and explores the biological effects of RXS-based nanomaterials, accompanied by a discussion and the outlook of the challenges faced and future clinical translations of RXS nanomedicines.

Nano-drug delivery system targeting tumor microenvironment: A prospective strategy for melanoma treatment

Melanoma, the most aggressive form of cutaneous malignancy arising from melanocytes, is frequently characterized by metastasis. Despite considerable progress in melanoma therapies, patients with advanced-stage disease often have a poor prognosis due to the limited efficacy, off-target effects, and toxicity associated with conventional drugs. Nanotechnology has emerged as a promising approach to address these challenges with nanoparticles capable of delivering therapeutic agents specifically to the tumor microenvironment (TME). However, the clinical approval of nanomedicines for melanoma treatment remains limited, necessitating further research to develop nanoparticles with improved biocompatibility and precise targeting capabilities. This comprehensive review provides an overview of the current research on nano-drug delivery systems for melanoma treatment, focusing on liposomes, polymeric nanoparticles, and inorganic nanoparticles. It discusses the potential of these nanoparticles for targeted drug delivery, as well as their ability to enhance the efficacy of conventional drugs while minimizing toxicity. Furthermore, this review emphasizes the significance of interdisciplinary collaboration between researchers from various fields to advance the development of nanomedicines. Overall, this review serves as a valuable resource for researchers and clinicians interested in the potential of nano-drug delivery systems for melanoma treatment and offers insights into future directions for research in this field.

In Situ Precision Cell Electrospinning as an Efficient Stem Cell Delivery Approach for Cutaneous Wound Healing

Mesenchymal stem cell (MSC) therapies have been brought forward as a promising treatment modality for cutaneous wound healing. However, current approaches for stem cell delivery have many drawbacks, such as lack of targetability and cell loss, leading to poor efficacy of stem cell therapy. To overcome these problems, in the present study, an in situ cell electrospinning system is developed as an attractive approach for stem cell delivery. MSCs have a high cell viability of over 90% even with a high applied voltage of 15 kV post-cell electrospinning process. In addition, cell electrospinning does not show any negative effect on the surface marker expression and differentiation capacity of MSCs. In vivo studies demonstrate that in situ cell electrospinning treatment can promote cutaneous wound healing through direct deposition of bioactive fish gelatin fibers and MSCs onto wound sites, leading to a synergic therapeutic effect. The approach enhances extracellular matrix remodeling by increasing collagen deposition, promotes angiogenesis by increasing the expression of vascular endothelial growth factor (VEGF) and forming small blood vessels, and dramatically reduces the expression of interleukin-6 (IL-6) during wound healing. The use of in situ cell electrospinning system potentially provides a rapid, no touch, personalized treatment for cutaneous wound healing.

Implantable, Biodegradable, and Wireless Triboelectric Devices for Cancer Therapy through Disrupting Microtubule and Actins Dynamics

Electric-field-based stimulation is emerging as a new cancer therapeutic modality through interfering with cell mitosis. To address its limitations of complicated wire connections, bulky devices, and coarse spatial resolution, an improved and alternative method is proposed for wirelessly delivering electrical stimulation into tumor tissues through designing an implantable, biodegradable, and wirelessly controlled therapeutic triboelectric nanogenerator (ET-TENG). With the excitation of ultrasound (US) to the ET-TENG, the implanted ET-TENG can generate an alternating current voltage and concurrently release the loaded anti-mitotic drugs into tumor tissues, which synergistically disrupts the assembly of microtubules and filament actins, induces cell cycle arrest, and finally enhances cell death. With the assistance of US, the device can be completely degraded after the therapy, getting free of a secondary surgical extraction. The device can not only work around those unresectable tumors, but also provides a new application of wireless electric field in cancer therapy.

Biodegradable trimethyl chitosan nanofiber mats by electrospinning as bioabsorbable dressings for wound closure and healing

The paper aimed to prepare quaternary chitosan-based nanofibers as bioabsorbable wound dressings. To this aim, fully biodegradable chitosan/N,N,N-trimethyl chitosan (TMC) nanofibers were designed and prepared via electrospinning, using poly(ethylene glycol) as sacrificial additive. The new biomaterials were structurally and morphologically characterized by FTIR and NMR spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy, and their properties required for wound dressings application were investigated and discussed in detail. Thus, the nanofiber behavior was investigated by swelling, dynamic vapor sorption, and in vitro biodegradation in media mimicking the wound exudate. The mechanical properties were analysed from the stress-strain curves, the bioadhesivity from the texture analysis and the mucoadhesivity from the Zeta potential and transmittance measurements. The antimicrobial activity was assessed against S. aureus and E. coli strains, and the biocompatibility was tested in vitro on normal human dermal fibroblasts, and in vivo on rats. The application of the fiber mats with the best balance of properties as dressings on deep burn wound models in rats showed wound closure and active healing, with fully restoration of epithelia. It was concluded that the combination of chitosan with TMC into nanofibers provides new potential bioabsorbable wound dressing, opening new perspectives in regenerative medicine.

Carrier-Free Binary Self-Assembled Nanomedicines Originated from Traditional Herb Medicine with Multifunction to Accelerate MRSA-Infected Wound Healing by Antibacterial, Anti-Inflammation and Promoting Angiogenesis

Background

Deaths from bacterial infections have risen year by year. This trend is further aggravated as the overuse antibiotics and the bacterial resistance to all known antibacterial agents. Therefore, new therapeutic alternatives are urgently needed.

Methods

Enlightenment the combination usage of traditional herb medicine, one carrier-free binary nanoparticles (GA-BBR NPs) was discovered, which was self-assembled from gallic acid and berberine through electrostatic interaction, π-π stacking and hydrophobic interaction; and it could be successfully prepared by a green, cost-effective and "one-pot" preparation process.

Results

The nanoparticles exhibited strong antibacterial activity and biofilm removal ability against multidrug-resistant S. aureus (MRSA) by downregulating mRNA expression of rpsF, rplC, rplN, rplX, rpsC, rpmC and rpsH to block bacterial translation mechanisms in vitro and in vivo, and it had well anti-inflammatory activity and a promising role in promoting angiogenesis to accelerate the wound healing on MRSA-infected wounds model in vivo. Additionally, the nanoparticles displayed well biocompatibility without cytotoxicity, hemolytic activity, and tissue or organ toxicity.

Conclusion

GA-BBR NPs originated from the drug combination has potential clinical transformation value, and this study provides a new idea for the design of carrier-free nanomedicine derived from natural herbals.

Matricaria chamomilla essential oil-loaded hybrid electrospun nanofibers based on polycaprolactone/sulfonated chitosan/ZIF-8 nanoparticles for wound healing acceleration

Recently, developing antibacterial wound dressings based on biomaterials display good biocompatibility and the potential to accelerate wound healing. For this aim, we prepared eco-friendly and biodegradable nanofibers (NFs) based on N-(3-sulfopropyl)chitosan/ poly (ε-caprolactone) incorporated by zeolite imidazolate framework-8 nanoparticles (ZIF-8 NPs) and chamomile essential oil (MCEO) via the electrospinning technique for their efficacy as wound dressing scaffolds. Fabricated NFs were characterized and studied for their structural, morphological, mechanical, hydrophilic, and thermal stability properties. The results of scanning electron microscopy (SEM) revealed that adding the ZIF-8 NPs/ MCEO, very slightly influenced the average diameter of NFs (PCL/SPCS (90:10) with 90 ± 32 nm). The developed uniform MCEO-loaded ZIF-8/PCL/SPCS NFs displayed better cytocompatibility, proliferation, and physicochemical properties (e.g. thermal stability and mechanical properties) than neat NFs. The results of cytocompatibility, DAPI (4',6-diamidino-2-phenylindole) staining study, and SEM micrographs demonstrated that formulated NFs had promising adhesion and proliferation against normal human foreskin fibroblasts-2 (HFF-2 cell line). The prepared NFs revealed excellent antibacterial activity against both Staphylococcus aureus and Escherichia coli with inhibition of 32.3 mm and 31.2 mm, respectively. Accordingly, the newly developed antibacterial NFs hold great potential as effective biomaterials for use as an active platform in wound healing applications.

NIR- and pH-responsive injectable nanocomposite alginate-graft-dopamine hydrogel for melanoma suppression and wound repair

Surgical excision, chemotherapy, and radiotherapy are the main approaches used for treating melanoma. Unfortunately, surgical excision usually inevitably causes large area skin defects. In addition, chemotherapy and radiotherapy are often accompanied by adverse reactions and multi-drug resistance. To overcome these limitations, a near-infrared (NIR)- and pH-responsive injectable nanocomposite hydrogel was developed using sodium alginate-graft-dopamine (SD) and biomimetic polydopamine-Fe(III)-doxorubicin nanoparticles (PFD NPs) for treating melanoma and promoting skin regeneration. Firstly, the SD/PFD hydrogel can precisely deliver anti-cancer agents to the tumor site to reduce its loss and off-target toxicity. Then, PFD can convert light into heat energy under NIR irradiation to kill cancer cells. Meanwhile, doxorubicin can be administered continuously and controllably by NIR- and pH-responsive. Additionally, the SD/PFD hydrogel can also relieve tumor hypoxia by decomposing endogenous hydrogen peroxide (H₂O₂) into oxygen (O₂). Therefore, photothermal, chemotherapy, and nanozyme synergetic therapy resulted in the tumor suppression. Specifically, the SA-based hydrogel can kill bacteria, scavenge reactive oxygen species, promote the proliferation and migration of cells, and significantly accelerate skin regeneration. Therefore, this study provides a safe and effective strategy for melanoma treatment and wound repair.

Recent Advances of Natural-Polymer-Based Hydrogels for Wound Antibacterial Therapeutics

Hydrogels have a three-dimensional network structure and high-water content, are similar in structure to the extracellular matrix, and are often used as wound dressings. Natural polymers have excellent biocompatibility and biodegradability and are commonly utilized to prepare hydrogels. Natural-polymer-based hydrogels can have excellent antibacterial and bioactive properties by loading antibacterial agents or being combined with therapeutics such as phototherapy, which has great advantages in the field of treatment of microbial infections. In the published reviews of hydrogels used in the treatment of infectious wounds, the common classification criteria of hydrogels include function, source of antibacterial properties, type of antibacterial agent, etc. However, there are few reviews on the classification of hydrogels based on raw materials, and the description of natural-polymer-based hydrogels is not comprehensive and detailed. In this paper, based on the principle of material classification, the characteristics of seven types of natural polymers that can be used to prepare hydrogels are discussed, respectively, and the application of natural-polymer-based hydrogels in the treatment of infectious wounds is described in detail. Finally, the research status, limitations, and prospects of natural-polymer-based hydrogels are briefly discussed.

Microenvironment responsive nanocomposite hydrogel with NIR photothermal therapy, vascularization and anti-inflammation for diabetic infected wound healing

Bacterial infection, excessive inflammation and damaging blood vessels network are the major factors to delay the healing of diabetic ulcer. At present, most of wound repair materials are passive and can't response to the wound microenvironment, resulting in a low utilization of bioactive substances and hence a poor therapeutic effect. Therefore, it's essential to design an intelligent wound dressing responsive to the wound microenvironment to achieve the release of drugs on-demand on the basis of multifunctionality. In this work, metformin-laden CuPDA NPs composite hydrogel (Met@ CuPDA NPs/HG) was fabricated by dynamic phenylborate bonding of gelatin modified by dopamine (Gel-DA), Cu-loaded polydopamine nanoparticles (CuPDA NPs) with hyaluronic acid modified by phenyl boronate acid (HA-PBA), which possessed good injectability, self-healing, adhesive and DPPH scavenging performance. The slow release of metformin was achieved by the interaction with CuPDA NPs, boric groups (B-N coordination) and the constraint of hydrogel network. Metformin had a pH and glucose responsive release behavior to treat different wound microenvironment intelligently. Moreover, CuPDA NPs endowed the hydrogel excellent photothermal responsiveness to kill bacteria of >95% within 10 min and also the slow release of Cu²⁺ to protect wound from infection for a long time. Met@ CuPDA NPs/HG also recruited cells to a certain direction and promoted vascularization by releasing Cu²⁺. More importantly, Met@CuPDA NPs/HG effectively decreased the inflammation by eliminating ROS and inhibiting the activation of NF-κB pathway. Animal experiments demonstrated that Met@CuPDA NPs/HG significantly promoted wound healing of diabetic SD rats by killing bacteria, inhibiting inflammation, improving angiogenesis and accelerating the deposition of ECM and collagen. Therefore, Met@CuPDA NPs/HG had a great application potential for diabetic wound healing.

Alleviate Periodontitis and Its Comorbidity Hypertension using a Nanoparticle-Embedded Functional Hydrogel System

Periodontitis and hypertension often occur as comorbidities, which need to be treated at the same time. To resolve this issue, a controlled-release composite hydrogel approach is proposed with dual antibacterial and anti-inflammatory activities as a resolution to achieve the goal of co-treatment of comorbidities. Specifically, chitosan (CS) with inherent antibacterial properties is cross-linked with antimicrobial peptide (AMP)-modified polyethylene glycol (PEG) to form a dual antibacterial hydrogel (CS-PA). Subsequently, curcumin loaded into biodegradable nanoparticles (CNP) are embedded in the hydrogel exhibiting high encapsulation efficiency and sustained release to achieve long-term anti-inflammatory activities. In a mouse model of periodontitis complicated with hypertension, CS-PA/CNP is applied to gingival sulcus and produced an optimal therapeutic effect on periodontitis and hypertension simultaneously. The therapeutic mechanisms are deeply studied and indicated that CS-PA/CNP exerted excellent immunoregulatory effects by suppressing the accumulation of lymphocytes and myeloid cells and enhanced the antioxidant capacity and thus the anti-inflammatory capacity of macrophages through the glutathione metabolism pathway. In conclusion, CS-PA/CNP has demonstrated its superior therapeutic effects and potential clinical translational value in the co-treatment of periodontitis and hypertension, and also serves as a drug delivery platform to provide combinatorial therapeutic options for periodontitis with complicated pathogenesis.

Curcumin-based nanoformulations alleviate wounds and related disorders: A comprehensive review

Despite numerous advantages, curcumin's (CUR) low solubility and low bioavailability limit its employment as a free drug. CUR-incorporated nanoformulation enhances the bioavailability and angiogenesis, collagen deposition, fibroblast proliferation, reepithelization, collagen synthesis, neovascularization, and granulation tissue formation in different wounds. Designing nanoformulations with controlled-release properties ensure the presence of CUR in the defective area during treatment. Different nanoformulations encompassing nanofibers, nanoparticles (NPs), nanospray, nanoemulsion, nanosuspension, nanoliposome, nanovesicle, and nanomicelle were described in the present study comprehensively. Moreover, for some other systems which contain nano-CUR or CUR nanoformulations, including some nanofibers, films, composites, scaffolds, gel, and hydrogels seems the CUR-loaded NPs incorporation has better control of the sustained release, and thereby, the presence of CUR until the final stages of wound healing is more possible. Incorporating CUR-loaded chitosan NPs into nanofiber increased the release time, while 80% of CUR was released during 240 h (10 days). Therefore, this system can guarantee the presence of CUR during the entire healing period. Furthermore, porous structures such as sponges, aerogels, some hydrogels, and scaffolds disclosed promising performance. These architectures with interconnected pores can mimic the native extracellular matrix, thereby facilitating attachment and infiltration of cells at the wound site, besides maintaining a free flow of nutrients and oxygen within the three-dimensional structure essential for rapid and proper wound healing, as well as enhancing mechanical strength.

Hierarchically Structured Hydroxyapatite Particles Facilitate the Enhanced Integration and Selective Anti-Tumor Effects of Amphiphilic Prodrug for Osteosarcoma Therapy

Efficient delivery of cargo into target cells is a formidable challenge in modern medicine. Despite the great promise of biomimetic hydroxyapatite (HA) particles in tissue engineering, their potential applications in bone tumor therapy, particularly their structure-function relationships in cargo delivery to target cells, have not yet been well explored. In this study, biomimetic multifunctional composite microparticles (Bm-cMPs) are developed by integrating an amphiphilic prodrug of curcumin with hierarchically structured HA microspheres (Hs-hMPs). Then, the effects of the hierarchical structure of vehicles on the integration and delivery of cargo as well as the anti-osteosarcoma (OS) effect of the composite are determined. Different hierarchical structures of the vehicles strongly influence the self-assembly behavior of the prodrug. The flake-like crystals of Hs-hMPs enable the highest loading capacity and enhance the stability of the cargo. Compared to the normal cells, OS cells exhibit 3.56-times better uptake of flake-like Hs-hMPs, facilitating the selective anti-tumor effect of the prodrug. Moreover, Bm-cMPs suppress tumor growth and metastasis by promoting apoptosis and inhibiting cell proliferation and tumor vascularization. The findings shed light on the potential application of Bm-cMPs and suggest a feasible strategy for developing an effective targeted therapy platform using hierarchically structured minerals for OS treatment.

Microstructure, Physical and Biological Properties, and BSA Binding Investigation of Electrospun Nanofibers Made of Poly(AA-co-ACMO) Copolymer and Polyurethane

In this study, poly(AA-co-ACMO) and polyurethane-based nanofibers were prepared in a ratio of 1:1 (NF11) and 2:1 (NF21) as antimicrobial carriers for chronic wound management. Different techniques were used to characterize the nanofibers, and poly(AA-co-ACMO) was mostly found on the surface of PU. With an increase in poly(AA-co-ACMO) dose from 0 (PU) and 1:1 (NF11) to 2:1 (NF21) in the casting solution, the contact angle (CA) was reduced from 137 and 95 to 24, respectively, and hydrophilicity was significantly increased. As most medications inhibit biological processes by binding to a specific protein, in vitro protein binding was investigated mechanistically using a stopped-flow technique. Both NF11 and NF21 bind to BSA via two reversible steps: a fast second-order binding followed by a slow first-order one. The overall parameters for NF11 (K_a = 1.1 × 10⁴ M^-1, K_d = 89.0 × 10^-6, ΔG⁰ = -23.1 kJ mol^-1) and NF21 (K_a = 189.0 × 10⁴ M^-1, K_d = 5.3 × 10^-6 M, ΔG⁰ = -27.5 kJ mol^-1) were determined and showed that the affinity for BSA is approximately (NF11)/(NF21) = 1/180. This indicates that NF21 has much higher BSA affinity than NF11, although BSA interacts with NF11 much faster. NF21 with higher hydrophilicity showed effective antibacterial properties compared to NF11, in agreement with kinetic data. The study provided an approach to manage chronic wounds and treating protein-containing wastewater.

Recapitulating Antioxidant and Antibacterial Compounds into a Package for Tissue Regeneration: Dual Function Materials with Synergistic Effect

Oxidative damage and infection can prevent or delay tissue repair. Moreover, infection reinforces reactive oxygen species (ROS) formation, which makes the wound's condition even worse. Therefore, the need for antioxidant and antibacterial agents is felt for tissue regeneration. There are emerging up-and-coming biomaterials that recapitulate both properties into a package, offering an effective solution to turn the wound back into a healing state. In this article, the principles of antioxidant and antibacterial activity are summarized. The review starts with biological aspects, getting the readers to familiarize themselves with tissue barriers against infection. This is followed by the chemistry and mechanism of action of antioxidant and antibacterial materials (dual function). Eventually, the outlook and challenges are underlined to provide where the dual-function biomaterials are and where they are going in the future. It is expected that the present article inspires the designing of dual-function biomaterials to more advanced levels by providing the fundamentals and comparative points of view and paving the clinical way for these materials.

Biochemical Characteristics and Potential Biomedical Applications of Hydrolyzed Carrageenans

Seaweed contains a variety of bioactive compounds; the most abundant of them are polysaccharides, which have significant biological and chemical importance. Although algal polysaccharides, especially the sulfated polysaccharides, have great potential in the pharmaceutical, medical and cosmeceutical sectors, the large molecular size often limits their industrial applications. The current study aims to determine the bioactivities of degraded red algal polysaccharides by several in vitro experiments. The molecular weight was determined by size-exclusion chromatography (SEC), and the structure was confirmed by FTIR and NMR. In comparison to the original furcellaran, the furcellaran with lower molecular weight had higher OH scavenging activities. The reduction in molecular weight of the sulfated polysaccharides resulted in a significant decrease in anticoagulant activities. Tyrosinase inhibition improved 2.5 times for hydrolyzed furcellaran. The alamarBlue assay was used to determine the effects of different Mw of furcellaran, κ-carrageenan and ι-carrageenan on the cell viability of RAW264.7, HDF and HaCaT cell lines. It was found that hydrolyzed κ-carrageenan and ι-carrageenan enhanced cell proliferation and improved wound healing, whereas hydrolyzed furcellaran did not affect cell proliferation in any of the cell lines. Nitric oxide (NO) production decreased sequentially as the Mw of the polysaccharides decreased, which indicates that hydrolyzed κ-Carrageenan, ι-carrageenan and furcellaran have the potential to treat inflammatory disease. These findings suggested that the bioactivities of polysaccharides were highly dependent on their Mw, and the hydrolyzed carrageenans could be used in new drug development as well as cosmeceutical applications.

Photoactivated MXene Nanosheets for Integrated Bone-Soft Tissue Therapy: Effect and Potential Mechanism

The bone defects caused by trauma are inevitably accompanied by soft tissue damage. The development of multifunctional bioactive biomaterials with integrated bone and soft tissue regeneration is necessary and needed urgently in orthopedics. In this work, we found that the photoactivated MXene (Ti₃C₂T_x) nanosheet showed positive effects on promoting both bone and soft tissue regeneration. We further investigated the detailed effect and potential mechanism of photoactivated MXene on tissue regeneration. Photoactivated MXene shows a good thermal effect and robust antibacterial activity to inhibit the expression of inflammation factors and methicillin-resistant Staphylococcus aureus (MRSA) infection and induces the expression of pro-angiogenic factors and soft tissue wound repair. Photoactivated MXene can also regulate the osteogenic differentiation of adipose-derived stem cells (ADSCs) through the ERK signaling pathway by activating the heat shock protein 70 (HSP70) and enhancing the repair of bone tissue. This work sheds light on the development of bioactive MXene with photothermal activation as an efficient strategy for bone and soft tissue regeneration simultaneously.

Recent Applications of Melanin-like Nanoparticles as Antioxidant Agents

Nanosized antioxidants are highly advantageous in terms of versatility and pharmacokinetics, with respect to conventional molecular ones. Melanin-like materials, artificial species inspired by natural melanin, combine recognized antioxidant (AOX) activity with a unique versatility of preparation and modification. Due to this versatility and documented biocompatibility, artificial melanin has been incorporated into a variety of nanoparticles (NP) in order to give new platforms for nanomedicine with enhanced AOX activity. In this review article, we first discuss the chemical mechanisms behind the AOX activity of materials in the context of the inhibition of the radical chain reaction responsible for the peroxidation of biomolecules. We also focus briefly on the AOX properties of melanin-like NP, considering the effect of parameters such as size, preparation methods and surface functionalization on them. Then, we consider the most recent and relevant applications of AOX melanin-like NPs that are able to counteract ferroptosis and be involved in the treatment of important diseases that affect, e.g., the cardiovascular and nervous systems, as well as the kidneys, liver and articulations. A specific section will be dedicated to cancer treatment, since the role of melanin in this context is still very debated. Finally, we propose future strategies in AOX development for a better chemical understanding of melanin-like materials. In particular, the composition and structure of these materials are still debated, and they present a high level of variability. Thus, a better understanding of the mechanism behind the interaction of melanin-like nanostructures with different radicals and highly reactive species would be highly advantageous for the design of more effective and specific AOX nano-agents.

Porcupine-inspired microneedles coupled with an adhesive back patching as dressing for accelerating diabetic wound healing

Diabetes chronic wound is a severe and frequently occurring medical issue in patients with diabetes that often leads to more serious complications. Microneedles (MNs) can be used for wound healing as they can effectively pierce the epidermis and inject drugs into the wound tissue. However, common MN patches cannot provide sufficient skin adhesion to prevent detachment from the wound area. Inspired by the barb hangnail microstructure of porcupine quills, a porcupine quill-like multilayer MN patch with an adhesive back patching for tissue adhesion and diabetic wound healing was designed. Sodium hyaluronate-modified CaO2 nanoparticles and metformin (hypoglycemic agent) were loaded into the polycaprolactone tips of MNs, endowing them with exceptional antibacterial ability and hypoglycemic effect. A flexible and adhesive back patching was formed by polyacrylamide-polydopamine/Cu2+ composite hydrogel, which ensures that the MN patches do not peel off from the application sites and reduce bacterial infection. The bioinspired multilayer structure of MN patches exhibits satisfactory mechanical and antibacterial properties, which is a potential multifunctional dressing platform for promoting wound healing. STATEMENT OF SIGNIFICANCE: The porcupine quill-like microneedles (MNs) with PAM-PDA/Cu2+ (PPC) composite hydrogel back patching have been fabricated, which can enhance the adhesion property of MNs to the skin through a physical interlock of multilayer MNs and chemical bonding of hydrogel patching. CaO2-HA NPs and metformin were loaded into the polycaprolactone tips of MNs, endowing them with the exceptional antibacterial ability and hypoglycemic effect, which could accelerate diabetic wound healing. As a safe and effective strategy in transdermal delivery of drugs, the as-fabricated flexible multilayer MN patch with good antibacterial, hypoglycemic, and biocompatibility has been used to promote the healing of diabetic wound by releasing oxygen and inhibiting inflammation at the wound site.