Wound Healing Infection Research Articles

A H₂S-Evolving Alternately-Catalytic Enzyme Bio-Heterojunction with Antibacterial and Macrophage-Reprogramming Activity for All-Stage Infectious Wound Regeneration.

The disorder of the macrophage phenotype and the hostile by-product of lactate evoked by pathogenic infection in hypoxic deep wound inevitably lead to the stagnant skin regeneration. In this study, hydrogen sulfide (H2S)-evolving alternately catalytic bio-heterojunction enzyme (AC-BioHJzyme) consisting of CuFe2S3 and lactate oxidase (LOD) named as CuFe2S3@LOD is developed. AC-BioHJzyme exhibits circular enzyme-mimetic antibacterial (EMA) activity and macrophage re-rousing capability, which can be activated by near-infrared-II (NIR-II) light. In this system, LOD exhausts lactate derived from bacterial anaerobic respiration and generated hydrogen peroxide (H2O2), which provides an abundant stock for the peroxidase-mimetic activity to convert the produced H2O2 into germicidal •OH. The GPx-mimetic activity endows AC-BioHJzyme with a glutathione consumption property to block the antioxidant systems in bacterial metabolism, while the O2 provided by the CAT-mimetic activity can generate 1O2 under the NIR-II irradiation. Synchronously, the H2S gas liberated from CuFe2S3@LOD under the infectious micromilieu allows the reduction of Fe(III)/Cu(II) to Fe(II)/Cu(І), resulting in sustained circular EMA activity. In vitro and in vivo assays indicate that the CuFe2S3@LOD AC-BioHJzyme significantly facilitates the infectious cutaneous regeneration by killing bacteria, facilitating epithelialization/collagen deposition, promoting angiogenesis, and reprogramming macrophages. This study provides a countermeasure for deep infectious wound healing via circular enzyme-mimetic antibiosis and macrophage re-rousing.

Vivo application of a portable plasma generator in infected wound healing

AbstractIn this study, a portable plasma generator produced large‐area air plasma for treating infected wounds in BALB/c mice. Different plasma treatment times (30 s, 1 min, 3 min, and 4.5 min) were applied daily until the wounds healed completely. Results showed reduced inflammation and increased vascular endothelial growth factor (VEGF) expression in tissues treated for 1 and 3 min, promoting blood vessel proliferation and collagen fiber synthesis. However, treatment for 30 s and 4.5 min worsened inflammation and decreased VEGF expression. Overall, a 1‐min treatment was the most effective in promoting wound healing. Cold plasma shows promise for healing infected wounds, with treatment duration being a crucial factor.

Preparation of Anticancer Extract

In India, the hibiscus rosa-sinesis (HS) flower is well-known and is used to worship Lord Ganesha. China rose, or Hibiscus rosa sinensis, is a member of the Malvaceae family. In numerous tropical nations, this plant has a wide range of significant medical benefits for treating wounds, inflammation, fever and coughing, diabetes, infections caused by bacteria and fungi, hair loss, and gastric ulcers. According to phytochemical analysis, flavonoids, tannin, terpenoids, saponins, and alkaloids are the principal bioactive substances in charge of its therapeutic benefits. Various pharmacological properties, including anti-pyritic, analgesic, anti-inflammatory, anxiety study, and anti-depressant, were demonstrated by experiment from recent study. These reviews seek to provide information on the different pharmacological and pharmaceutical uses of Hibiscus rosa sinensis. The article discusses a few literary works that are based on the studies conducted on Hibiscus rosa sinensis. Background: Infectious diseases are the most common causes of morbidity and mortality in developing countries.Wound and wound infections are also major health problem. Nowadays, medicinal plants play a major role intreatment of infectious diseases and wound healing and they are easily available and more affordable as comparedto synthetic compounds. The aim of this study is therefore, to investigate the antibacterial and wound healingactivities of 80% methanol extract of Hibiscus micranthus leaves using disc diffusion methods and rat excisionmodel respectively.Methods: In vitro antibacterial screening was carried out against S. aureus, S.pneumoniae, S. pyogenes, E. coli, P.aeruginosa, K. pneumoniae and P. mirabilis bacterial strains using disc-well diffusion assay. Would healing activity wasdone in rats divided into four groups each consisting of six animals. Group I was served as a negative control(ointment base), Group II served as a positive control Nitrofurazone (NFZ 0.2% ointment), Groups III and IV wastreated 5 and 10% extracts respectively. The acute oral toxicity test and skin sensitivity test were also performed before conducting the actual study. The extract was analyzed for secondary meta using.

Periplaneta americana extract promotes infectious diabetic ulcers wound healing by downregulation of LINC01133/SLAMF9

Wound healing in diabetic ulcers remains a significant clinical challenge, primarily due to bacterial infection and impaired angiogenesis. Periplaneta americana extract (PAE) has been widely used to treat diabetic wounds, yet its underlying mechanisms are not fully understood. This study aimed to elucidate these mechanisms by analyzing long non-coding RNA (lncRNA) expressions in the wound tissues from diabetic anal fistula patients treated with or without PAE, using high-throughput sequencing. Peripheral blood monocytes from patients were differentiated into M0 macrophages with human macrophage colony-stimulating factor (hM-CSF) and subsequently polarized into M1 macrophages with lipopolysaccharide. The results indicated that LINC01133 and SLAMF9 were downregulated in wound tissues of patients treated with PAE. Furthermore, PAE suppressed M1 macrophage polarization and enhanced human umbilical vein endothelial cell (HUVEC) proliferation, migration, and angiogenesis. These effects were diminished when LINC01133 or SLAMF9 were overexpressed. Mechanistically, LINC01133 was shown to upregulate SLAMF9 through interaction with ELAVL1. Overexpression of SLAMF9 reversed the effects of LINC01133 silencing on macrophage polarization and HUVEC functions. In conclusion, PAE facilitates the healing of infected diabetic ulcers by downregulating the LINC01133/SLAMF9 pathway.

Exploring trauma surgeons' views on trauma care in Nigeria: A qualitative study

BackgroundIn Nigeria, trauma care faces challenges due to high injury and death rates from road traffic accidents and violence. Improvements are underway, but gaps in service availability, training, and coordination persist, necessitating evidence-based interventions. PurposeTo evaluate trauma care practices in Nigeria, focusing on practitioners' perceptions of training, resources, and care quality to inform policy and practice enhancements. MethodsAn exploratory qualitative study was conducted with seven trauma surgeons across Nigeria, using semi-structured interviews and an Interpretive Description analysis approach, adhering to SRQR standards. ResultsAnalysis of interviews with seven Nigerian trauma surgeons highlighted a trauma care system burdened by high incidences of traffic-related injuries. Despite varying caseloads—from 20 cases per month to 65 weekly—common challenges included delayed care, leading to complications like infection and misaligned wound healing. Surgeons noted strengths in motivated staff and sub-specialization but stressed barriers such as underdeveloped prehospital care, financial constraints, and resource shortages, which hindered effective trauma management and outcomes. ConclusionsEffective trauma care in Nigeria is crucial and achievable through policy reforms, better resource distribution, and enhanced training. Systematic data collection and a national trauma care protocol are recommended to improve patient outcomes and guide future research and policymaking.

“All-in-one” self-healing and injectable cationic guar gum hydrogel dressing functionalized by bioactive complexes composed of natural small molecules

Reducing the risk of wound infection is an urgent issue health priority. Antibacterial polysaccharide-based hydrogels have attracted great attention for infectious wounds, attributed to their safe antimicrobial performance and natural non-toxicity and biodegradability advantages. In this study, the “all-in-one” self-adaptive and injectable cationic guar gum (CG)-based polysaccharide hydrogels (FA-TOB/CG) loaded with bioactive complexes were developed for infectious wound healing. The constructed antioxidant and antibacterial ferulic acid (FA)-tobramycin (TOB) bioactive complexes (FA-TOB) were used as the cross-linking agent and introduced into the CG matrix to construct the FA-TOB/CG hydrogel with a three-dimensional porous structure. The sterilization rates of FA-TOB/CG hydrogel against S. aureus and E. coli reached 98 % and 80 % respectively. In addition, the FA-TOB/CG also exhibits enhanced antioxidant performances (DPPH: > 40 %; ABTS: > 90 %; ·OH: > 50 %). More importantly, FA-TOB/CG hydrogel also showed the ability to sustain the release of FA and TOB. These superiorities of the FA-TOB/CG hydrogel enabled it to provide a moist wound environment and promote wound healing by eliminating bacteria, modulating the local inflammatory response, and accelerating collagen deposition and vascular regeneration. Thus, this study may enlarge a new sight for developing multifunctional dressings by incorporating bioactive complexes into polysaccharide hydrogels for infected wounds.

A New Nanoplatform Under NIR Released ROS Enhanced Photodynamic Therapy and Low Temperature Photothermal Therapy for Antibacterial and Wound Repair.

Skin injury, often caused by physical or medical mishaps, presents a significant challenge as wound healing is critical to restore skin integrity and tissue function. However, external factors such as infection and inflammation can hinder wound healing, highlighting the importance of developing biomaterials with antibiotic and wound healing properties to treat infections and inflammation. In this study, a novel photothermal nanomaterial (MMPI) was synthesized for infected wound healing by loading indocyanine green (ICG) on magnesium-incorporated mesoporous bioactive glass (Mg-MBG) and coating its surface with polydopamine (PDA). In this study, Mg-MBG and MMPI was synthesized via the sol-gel method and characterized it using various techniques such as scanning electron microscopy (SEM), the energy dispersive X-ray spectrometry (EDS) system and X-ray diffraction (XRD). The cytocompatibility of MMPI was evaluated by confocal laser scanning microscopy (CLSM), CCK8 assay, live/dead staining and F-actin staining of the cytoskeleton. The antibacterial efficiency was assessed using bacterial dead-acting staining, spread plate method (SPM) and TEM. The impact of MMPI on macrophage polarization was initially evaluated through flow cytometry, qPCR and ELISA. Additionally, an in vivo experiment was performed on a mouse model with skin excision infected. Histological analysis and RNA-seq analysis were utilized to analyze the in vivo wound healing and immunomodulation effect. Collectively, the new photothermal and photodynamic nanomaterial (MMPI) can achieve low-temperature antibacterial activity while accelerating wound healing, holds broad application prospects.

Polydopamine-armored zeolitic imidazolate framework-8-incorporated zwitterionic hydrogel with multifunctional properties for infected wound healing

Diabetic skin wound healing is compromised by bacterial infections, oxidative stress, and vascular disruption, leading to delayed recovery and potential complications. This study developed an antibacterial, antioxidant, and adhesive hydrogel dressing that promotes rapid bacterial-infected diabetic wound healing using the biological macromolecule of polydopamine (PDA). This hydrogel comprised PDA-armored zeolitic imidazolate framework-8 nanoparticles (PDA@ZIF-8 NPs) combined with a second armor of zwitterionic polymer network (poly(acrylamide-co-sulfobetaine methacrylate); PAS), realizing low concentration Zn2+ release, good adhesion (14.7 kPa for porcine skin), and improved tensile strength (83.2 kPa). The hydrogel exhibited good antibacterial efficacy against both Staphylococcus aureus (S. aureus, 92.8 %), Escherichia coli (E. coli, 99.6 %) and methicillin-resistant S. aureus (MRSA, 99.2 %), which was attributed to the properties of the incorporated PDA@ZIF-8 NPs. Notably, in vitro, the PDA@ZIF-8 PAS hydrogel not only promoted fibroblast proliferation and migration but also facilitated endothelial cell angiogenesis. In vivo, the PDA@ZIF-8 PAS hydrogel retained its Zn2+-releasing function and effectively suppressed bacterial growth in infected wounds, thereby accelerating the regeneration of both normal and diabetic wounds. This multiarmored hydrogel is a promising sustained-release carrier for functional metal ions and drugs, making it applicable for not only skin healing, but potentially the regeneration of other complex tissues.

Dynamic bond crosslinked maca polysaccharide hydrogels with reactive oxygen species scavenging and antibacterial effects on infected wound healing

In this study, a polysaccharide fragment with antioxidant and reactive oxygen species (ROS) scavenging activities was extracted from Maca (Lepidium meyenii Walp.) and subjected to structural analyses. The fragment, characterized by the α-D-Glcp-(1 → terminal group of the main chain linked to the →4)-Glcp-(1 → end unit through an O-6 bond and the O-3 bond of 1–3-4Glcp, was modified by introducing dialdehyde structures on its glucose units. It was then crosslinked with N-carboxymethyl chitosan via the Schiff base reaction to create a multifunctional hydrogel with antibacterial and ROS scavenging properties. Polyvinyl alcohol was incorporated to form a double crosslinked gel network, and the addition of silver nanoparticles enhanced its antibacterial efficacy. This gel system can scavenge excess ROS, mitigate wound inflammation, eradicate harmful bacteria, and aid in the restoration of skin microecology. The multifunctional maca polysaccharide hydrogel shows significant potential as a medical dressing for the treatment of infected wounds.

A novel multifunction of wearable ionic conductive hydrogel sensor for promoting infected wound healing

Conductive hydrogels have attracted widespread attention in applications of artificial biological tissues and ionic skin. Herein, a highly ionically conductive and biocompatibility hydrogels that integrate sensing, low swelling, and antimicrobial are prepared by the composition of chitosan (CS) chains, tannic acid (TA), polyacrylic acid (PAA), and metal cations. The hydrogels with high conductivity had tensile strain repeatable adhesion, wide strain detection, biocompatibility, and motion sensing capabilities. Particularly, in the aspect of hydrogel strain sensing based on ion conduction, it has high nonliearity (GF=2.05) with a large strain (20 %-1400 %), and excellent cycle stability. In addition, owing to the low-swelling effect and dipole-dipole interaction between the existence of free catechol groups of the zwitterionic group and TA in the zwitterionic sulfobetaine methacrylate (SBMA), the hydrogels display repeatable and controllable adhesiveness. Meanwhile, the covalent cross-linking between AA and SBMA synergistically enhances the mechanical properties of the hydrogels (169 kPa, 1474 %). Furthermore, as demonstrated in the L929 mouse wound infection model, the results indicated that the prepared hydrogel group had antimicrobial activity and reduced inflammation, thereby accelerating wound healing. The biocompatible and mutli-functional conductive hydrogels provide a new method for the design of novel type ionic skin device.

Heparin mimicking sulfonated polyester synergistically promotes bacterial Infected-Wound healing with ROS responsive cinnamaldehyde based prodrugs

Excessive antibiotic usage has resulted in antibiotic resistance. This work introduces a novel ROS-responsive, cinnamaldehyde (CA)-based sulfonated all-polyester prodrug (RCSAP) to combat antibiotic resistance. RCSAP is a unique amphiphilic pseudo triblock copolymer comprising of two hydrophilic, heparin-mimicking sulfonated polyester (HSP) blocks and a hydrophobic polymeric block containing ROS-responsive CA thioacetal. RCSAP nanoparticles (NPs) not only achieve self-amplifying degradation and release, but orchestrate a “dual wielding” synergistic antibacterial mechanism. HSP shell competes with bacteria for host cell surface binding, hindering its internalization and infection. Simultaneously, ROS-responsive core liberates CA, boosting bacterial membrane permeability. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined. RCSAP NPs display exceptional antibacterial efficacy against both E. coli and S. aureus, as confirmed by survival analysis, colony-forming unit (CFU) quantification, microbial growth curve analysis, and live/dead bacterial viability assays. Importantly, RCSAP NPs effectively eradicated methicillin-resistant Staphylococcus aureus (MRSA). In addition, RCSAP NPs possess the unique ability to bind to S. aureus, aggregate and precipitate it. They competitively hinder S. aureus infection in both ARPE-19 and 293 T cells. Molecular simulation further verified the electrostatic interactions between HSP and the S. aureus SpA protein, which may mediate the binding of RCSAP NPs to S. aureus. In vivo assessments demonstrated that RCSAP NPs significantly accelerates wound healing in S. aureus-infected models, with excellent biocompatibility and minimal systemic toxicity. This work paves the way for all-polyester-based nanomedicines harnessing the power of natural antibacterial and heparin-mimicking agents synergistically for enhanced disinfection and wound healing, curbing drug resistance.

A functional hydrogel of dopamine-modified gelatin with photothermal properties for enhancing infected wound healing

Infected skin wound has gradually become a prevalent injury that affects overall health. Currently, biomaterials with good adhesion, efficient antibacterial properties, and angiogenesis are considered as a suitable way to effectively heal infected wound. Herein, a multifunctional hydrogel comprising gelatin, dopamine (DA), and ferric ions (Fe3+) was developed for infected wound healing. The modified gelatin-dopamine (Gel-DA) enhanced adhesive capability. Subsequently introducing ferric ions (Fe3+) to form Gel-DA-Fe3+ hydrogels by Fe3+ and catechol coordination bonds. The designed hydrogels demonstrated multifaceted functionality, encompassing photothermal antibacterial, angiogenesis, and so on. The introduction of DA enhanced the adhesion of Gel-DA-Fe3+ to the skin surface and might serve as a physical barrier to seal wound. Meanwhile, DA and Fe3+ jointly endowed good photothermal effects to composite hydrogels, which could eliminate over 95 % of bacteria. In vitro results revealed that Gel-DA-Fe3+ hydrogels had good biocompatibility and promoted HUVECs migration and tube formation. Furthermore, in vivo studies confirmed that Gel-DA-Fe3+ hydrogels markedly expedited the wound healing of rats through eradicating bacteria, accelerating the deposition of collagen, and promoting angiogenesis. What’s more, Gel-DA-Fe3+ hydrogels under near-infrared laser had a more pronounced ability for wound healing. Therefore, Gel-DA-Fe3+ hydrogels had great potential for application in bacteria-infected wound healing.

Bioclay Enzyme with Bimetal Synergistic Sterilization and Infectious Wound Regeneration.

Bacteria invasion is the main factor hindering the wound-healing process. However, current antibacterial therapies inevitably face complex challenges, such as the abuse of antibiotics or severe inflammation during treatment. Here, a drug-free bioclay enzyme (Bio-Clayzyme) consisting of Fe2+-tannic acid (TA) network-coated kaolinite nanoclay and glucose oxidase (GOx) was reported to destroy harmful bacteria via bimetal antibacterial therapy. At the wound site, Bio-Clayzyme was found to enhance the generation of toxic hydroxyl radicals for sterilization via cascade catalysis of GOx and Fe2+-mediated peroxidase mimetic activity. Specifically, the acidic characteristics of the infection microenvironment accelerated the release of Al3+ from kaolinite, which further led to bacterial membrane damage and amplified the antibacterial toxicity of Fe2+. Besides, Bio-Clayzyme also performed hemostasis and anti-inflammatory functions inherited from Kaol and TA. By the combination of hemostasis and anti-inflammatory and bimetal synergistic sterilization, Bio-Clayzyme achieves efficient healing of infected wounds, providing a revolutionary approach for infectious wound regeneration.

Effect of collagen hydrogel containing Lavandula officinalis essential oil nanoemulsion in wound healing of infectious burn.

The main cause of mortality in burn patients is infection from burns. Drug-resistant bacteria are the main causes of wound infection, so alternative antibiotic therapies hold significant importance. The objective of this study was to examine the impact of a collagen hydrogel that contains a nanoemulsion of Lavandula essential oil on the healing process of infected burn wounds. In this experimental study, 20 rats were randomly divided after applying burns with a 10 mm diameter hot plate and infecting the wounds with multidrug-resistant Pseudomonas aeruginosa into four groups, including a positive control, a negative control, the first experiment (collagen hydrogel), and the second experiment (collagen hydrogel containing Lavandula essential oil nanoemulsion). On the 4th, 11th, and 18th days, tissue samples were taken for pathology studies. The important parameters in burn wound healing with hematoxylin and eosin and Masson's trichrome staining methods were investigated and scored according to Abramov's method. Based on the pathology findings, experimental groups 1 and 2 compared to the negative and positive control groups were effective in rat infection wound healing. The hydrogel scaffold in the experimental groups increased fibroblasts and angiogenesis compared to the control groups. Epithelization was noticed only in the hydrogel group containing nanoemulsion. The study findings suggest that the use of collagen hydrogel with Lavandula essential oil nanoemulsion has potential as a wound dressing. This is because it has the potential to effectively promote healing and act as an antibacterial agent to prevent infections.

Multifunctional composite soluble microneedle patch based on “one stone, three birds” strategy for promoting the healing of infectious wounds

The colonisation of microorganisms such as bacteria forms a biofilm barrier on the wound's surface, preventing or delaying the penetration of antibacterial drugs. At the same time, continuous bacterial infection can cause oxidative stress and an inflammatory response and hinder angiogenesis, resulting in difficult wound healing. Based on the “one stone, three birds” strategy, a multi-functional nanoparticle composite soluble microneedle was designed and developed to solve this dilemma better. Ginsenoside-liposomes(R-Lipo) were prepared by ginsenoside Rg3, which had the effect of promoting repair, instead of cholesterol, and loaded with berberine (Ber), the antibacterial component of Coptis, together with polydopamine (PDA), which had anti-inflammatory and antioxidant properties, into microneedles based on hyaluronic acid (PDA/R-Lipo@BerMN). PDA/R-Lipo@BerMN tip can penetrate and destroy the integrity of the biofilm, dissolve under the action of hyaluronidase in the skin, and gradually release the drug to achieve rapid antibacterial, anti-inflammatory, antioxidant, and proliferation. As expected, the PDA/R-Lipo@BerMN patch effectively cleared ROS during wound closure, further promoted M2 macrophage polarisation, eradicated bacterial infection, and regulated the immune microenvironment, promoting inflammation suppression, collagen deposition, angiogenesis, and tissue regeneration.

Cell Wall Binding Strategies Based on Cu3SbS3 Nanoparticles for Selective Bacterial Elimination and Promotion of Infected Wound Healing.

Utilizing nanomaterials as an alternative to antibiotics, with a focus on maintaining high biosafety, has emerged as a promising strategy to combat antibiotic resistance. Nevertheless, the challenge lies in the indiscriminate attack of nanomaterials on both bacterial and mammalian cells, which limits their practicality. Herein, Cu3SbS3 nanoparticles (NPs) capable of generating reactive oxygen species (ROS) are discovered to selectively adsorb and eliminate bacteria without causing obvious harm to mammalian cells, thanks to the interaction between O of N-acetylmuramic acid in bacterial cell walls and Cu of the NPs. Coupled with the short diffusion distance of ROS in the surrounding medium, a selective antibacterial effect is achieved. Additionally, the antibacterial mechanism is then identified: Cu3SbS3 NPs catalyze the generation of O2•-, which has subsequently been conversed by superoxide dismutase to H2O2. The latter is secondary catalyzed by the NPs to form •OH and 1O2, initiating an in situ attack on bacteria. This process depletes bacterial glutathione in conjunction with the disruption of the antioxidant defense system of bacteria. Notably, Cu3SbS3 NPs are demonstrated to efficiently impede biofilm formation; thus, a healing of MRSA-infected wounds was promoted. The bacterial cell wall-binding nanoantibacterial agents can be widely expanded through diversified design.

Ferroelectric catalytic BaTiO3‐based composite insoles to promote healing of infected wounds: Analysis of antibacterial efficacy and angiogenesis

AbstractOur feet are often subjected to moist and warm environments, which can promote the growth of harmful bacteria and the development of severe infection in wounds located in the foot. As a result, there is a need for new and innovative strategies to safely sterilize feet, when shoes are worn, to prevent any potential foot‐related diseases. In this paper, we have produced a non‐destructive, biocompatible and convenient‐to‐use insole by embedding a BaTiO3 (BT) ferroelectric material into a conventional polydimethylsilane (PDMS) insole material to exploit a ferroelectric catalytic effect to promote the antibacterial and healing of infected wounds via the ferroelectric charges generated during walking. The formation of reactive oxygen species generated through a ferroelectric catalytic effect in the PDMS‐BT composite is shown to increase the oxidative stress on bacteria and decrease both the activity of bacteria and the rate of formation of bacterial biofilms. In addition, the ferroelectric field generated by the PDMS‐BT insole can enhance the level of transforming growth factor‐beta and CD31 by influencing the endogenous electric field of a wound, thereby promoting the proliferation, differentiation of fibroblasts and angiogenesis. This work therefore provides a new route for antimicrobial and tissue reconstruction by integrating a ferroelectric biomaterial into a shoe insole, with significant potential for health‐related applications.

A 2D self-cascade catalytic system based on CoCuFe-LDH nanosheets for accelerated healing of infected wounds

The emergence of drug-resistant bacteria has rendered traditional antibiotics ineffective, posing a serious threat to human health. There is an urgent need to find alternative antimicrobial agents. Inspired by enzyme immobilization and multi-enzyme biocatalysis, we have designed a tri-metal layered double hydroxide (LDHs)-based cascade catalytic system (CoCuFe-LDH@Gox nanosheets) for treating drug-resistant bacterial infections and promoting wound healing. The synergistic effects of the Co, Cu, and Fe in the tri-metal LDHs structure endow CoCuFe-LDH nanosheets with excellent peroxidase (POD)-like activity. The large specific surface area of CoCuFe-LDH nanosheets render them ideal carriers for glucose oxidase (Gox). CoCuFe-LDH@Gox nanosheets can catalyze glucose to produce gluconic acid and H2O2. The generated gluconic acid decreases the local pH, further enhancing the POD-like activity of CoCuFe-LDH@Gox nanosheets at wound site. CoCuFe-LDH@Gox nanosheets can then catalyze H2O2 generating hydroxyl radicals (•OH) to effectively kill drug-resistant bacteria. This synergistic integration of the catalytic LDHs and the Gox components enables the cascade catalytic system to be highly effective against drug-resistant bacteria. In addition to its remarkable antibacterial properties, this LDHs-based system also exhibits excellent biocompatibility and considerable immunomodulatory capabilities. It can accelerate the healing of drug-resistant bacteria-infected wounds by inhibiting the inflammatory response and regulating macrophage polarization. These multifunctional attributes make the CoCuFe-LDH@Gox nanosheets a highly promising candidate for the treatment of drug-resistant bacterial infections in future clinical applications.

Green synthesis-inspired antibacterial, antioxidant and adhesive hydrogels with ultra-fast gelation and hemostasis for promoting infected skin wound healing

Bacterial infections are a serious threat to wound healing and skin regeneration. In recent years, photothermal therapy (PTT) has become one of the most promising tools in the treatment of infectious diseases. However, wound dressings with photo-responsive properties are currently still limited by the difficulties of biosafety and thermal stability brought by the introduction of photosensitizers or photothermal agents. Therefore, how to improve the therapeutic efficiency and biosafety from material design is still a major challenge at present. In this study, the carboxymethyl chitosan (CMCS) and protocatechuic aldehyde (PA) hydrogels based on horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) enzymatic catalysis was developed. Therein, HRP and H2O2 catalyzed cross-linking while polymerizing PA, which not only endowed the hydrogels with photothermal responsiveness but also with good biosafety through this enzyme-catalyzed green approach. Meanwhile, the hydrogels possessed highly efficient bacteriostatic ability with the assistance of near infrared (NIR). Moreover, the ultra-rapid gelation, strong tissue adhesion, high swelling ability, good antioxidant property and hemostatic property of the CMCS-PA hydrogels based on HRP/H2O2 enzymatic catalysis were suitable for the treatment of skin wounds. Meanwhile, NIR-assistant CMCS-PA hydrogels based on HRP/H2O2 enzymatic catalysis reduced inflammation, decreased bacterial infection, and promoted collagen deposition and angiogenesis, which showed remarkable therapeutic effects in a skin wound infection model. All results indicate that this green approach to introduce photothermal property by HRP-catalyzed PA polymerization endows the hydrogels with efficient photothermal conversion efficiency, suggesting that they are promising to provide new options for replacing photothermal agents and photosensitizers. Statement of significanceIn recent years, wound dressings with photo-responsive properties are currently still limited by the difficulties of biosafety and thermal stability brought by the introduction of agent photosensitizers or photothermal agents. In this study, the carboxymethyl chitosan and protocatechuic aldehyde hydrogels based on horseradish peroxidase and hydrogen peroxide enzymatic catalysis was developed. The photothermal properties of hydrogels were transformed from absent to present just by horseradish peroxidase-catalyzed protocatechuic aldehyde polymerization in a green approach. Meanwhile, the hydrogels possessed highly efficient bacteriostatic ability with the assistance of near infrared. The green approach of introducing photothermal properties from material design solves the biosafety challenge. Therefore, this study is expected to provide new options for alternative photothermal agents and photosensitizers.

Silicone Bioadhesive with Shear-Stiffening Effect: Rate-Responsive Adhesion Behavior and Wound Dressing Application.

Stimuli-responsive adhesives with on-demand adhesion capabilities are highly advantageous for facilitating wound healing. However, the triggering conditions of stimuli-responsive adhesives are cumbersome, even though some of them are detrimental to the adhesive and adjacent natural tissues. Herein, a novel stimuli-responsive adhesive called shear-stiffening adhesive (SSA) has been created by constructing a poly(diborosiloxane)-based silicone network for the first time, and SSA exhibits a rate-responsive adhesion behavior. Furthermore, we introduced bactericidal factors (PVP-I) into SSA and applied it as a wound dressing to promote the healing of infected wounds. Impressively, the wound dressing not only has excellent biocompatibility and long-term antibacterial properties but also performs well in accelerating wound healing. Therefore, this study provides a new strategy for the synthesis of intelligent adhesives with force rate response, which simplifies the triggering conditions by the force rate. Thus, SSA has great potential to be applied in wound management as an intelligent bioadhesive with on-demand adhesion performance.