Therapy Of Chronic Wounds Research Articles

Multifunctional Microneedle Patches Loaded With Engineered Nitric Oxide-Releasing Nanocarriers for Targeted and Synergistic Chronic Wound Therapy.

Chronic wounds impose significant physical and mental burdens on patients. Nano-based formulations offer a promising strategy for chronic wound healing due to their non-invasive nature and enhanced biofilms penetration, but they often lack targeting capability or fail to achieve long-term and synergistic effects. In this work, a multifunctional microneedle (MN) patch loaded with engineered nitric oxide (NO)-releasing nanocarriers are presented that encapsulate an antibacterial agent and are immobilized with Concanavalin A (Con A) and NO molecules for targeted and synergistic treatment of chronic wounds. With the assistance of MNs, the nanoparticles (NPs) can directly cross bacterial biofilms and be efficiently delivered to wound tissues, where they target harmful bacteria through the specific recognition between Con A and polysaccharides on bacterial surfaces, followed by the release of the encapsulated antimicrobial agent, thereby achieving effective antibacterial effect. Moreover, the NPs generate NO in a sustained manner as they dissociate in the wound tissue, which exerts potent anti-inflammatory action and benefits tissue regeneration, further promoting chronic wounds closure. Consequently, this work provides a novel MN patch loaded with engineered NPs designed for accelerating chronic wound healing through targeted and synergistic therapy.

Hyperbaric oxygen therapy for healing chronic foot wounds in diabetic patients: Randomised clinical trial

Introduction: foot wounds are highly prevalent in diabetic patients and can lead to limb amputation; thus, this pathology requires comprehensive treatment. Objective: the primary objective of this study was to evaluate the effectiveness of Hyperbaric oxygen therapy in improving the healing of diabetic foot ulcers. The secondary objective was to evaluate whether it reduces the number of amputations and enhances the quality of life. Methods: this non-blind randomized clinical study included diabetic patients who presented chronic foot ulcers classified as Wagner grades 2, 3, and 4. The sample consisted of 30 patients, 17 allocated to the control group and 13 to Hyperbaric oxygen therapy group. Hyperbaric oxygen therapy was applied once a day, five days a week for seven weeks; each session lasted 90min at 2.5 atmospheres absolute. The SF-36 quality of life questionnaire was administered to both groups. Results: the evaluation of foot wound healing in diabetic patients showed a better result in the Hyperbaric oxygen therapy group less than six months of follow-up (p = 0.04). There were two minor amputations in the control group with p=0.60. Furthermore, the quality of life was improved in the Hyperbaric oxygen therapy group compared to the control, with a statistically significant difference in most domains, except for mental health. Conclusions: our findings suggest that Hyperbaric oxygen therapy positively impacts the healing of foot wounds in diabetic patients who have undergone less than six months of follow-up. Data regarding the method’s benefit related to the reduction of minor or significant amputations are insufficient. Regarding quality of life, we obtained results that support the use of Hyperbaric oxygen therapy. Registration number RBR-7bd3xy (http://www.ensaiosclinicos.gov.br).

Advances in Metal and Metal Oxide Nanomaterials for Topical Antimicrobial Applications: Insights and Future Perspectives.

Nanotechnology has seen significant growth in the past few decades, with the use of nanomaterials reaching a wide scale. Given that antimicrobial resistance is peaking, nanotechnology holds distinct potential in this area. This review discusses recent applications of metal and metal oxide nanoparticles as antibacterial, antifungal, and antiviral agents, particularly focusing on their topical applications and their role in chronic wound therapy. We explore their use in various forms, including coated, encapsulated, and incorporated in hydrogels or as complexes, proposing them as topical antimicrobials with promising properties. Some studies have shown that metal and metal oxide nanoparticles can exhibit cytotoxic and genotoxic effects, while others have found no such properties. These effects depend on factors such as nanoparticle size, shape, concentration, and other characteristics. It is essential to establish the dose or concentration associated with potential toxic effects and to investigate the severity of these effects to determine a threshold below which metal or metal oxide nanoparticles will not produce negative outcomes. Therefore, further research should focus on safety assessments, ensuring that metal and metal oxide nanoparticles can be safely used as therapeutics in biomedical sciences.

Dental Pulp Stem Cell Lysate-Based Hydrogel Improves Diabetic Wound Healing via the Regulation of Anti-Inflammatory Macrophages and Keratinocytes.

The prolonged existence of chronic wounds heightens the risk of patients experiencing chronic pain, necrosis, and amputation. Dental pulp stem cells (DPSCs) have garnered attention due to their potential immunomodulatory and tissue repair regenerative effects in the management of chronic wounds. However, stem-cell-based therapy faces challenges such as malignant differentiation, immune rejection, and long-term effectiveness. To overcome these challenges, we proposed a chronic wound therapy using a hydrogel derived from human-originated dental pulp stem cell lysate (DPSCL). Our data indicate that, with the degradation of the dental pulp stem cell lysate-based hydrogel (DPSCLH), the slowly released cell lysates recruit anti-inflammatory M2 macrophages and promote the proliferation, migration, and keratinization of HacaT cells. In addition, in vivo studies revealed that DPSCLH avoids immune rejection reactions and induces a long-term accumulation of endogenous M2 macrophages. In a mouse model of diabetic wounds, DPSCLH effectively modulates the inflammatory microenvironment around diabetic wounds, promotes the formation of the stratum corneum, and facilitates the healing of wounds, thus holding tremendous potential for the treatment of diabetic wounds.

A Flexible Antibacterial Gel Electrochemiluminescence Device for Monitoring and Therapy of Chronic Diabetic Wounds

ABSTRACTThe rapid development of internal light‐driven photodynamic therapy stems from its capability to eliminate bulky physical light sources, addressing the medical requirements for comfort and portability in long‐term diabetic wound management. To overcome limitations such as tissue penetration depth and controllability of internal light sources, this study introduces an antibacterial gel electrochemiluminescence device for the treatment of diabetic wounds and the monitoring of wound bacteria. We deploy a large‐area luminescent device combining flexible screen‐printed electrodes and a dual‐network hydrogel, in which photodynamic therapy is driven by Ru@COFs' nanoconfinement‐enhanced near‐infrared electrochemiluminescence to achieve a deeper and safer antibacterial effect. The custom‐sized screen‐printed electrodes inherit the inborn electrochemical sensing function and enable intimate contact between reactive oxygen species and the wound. The device avoids physical light sources and provides a new paradigm for developing miniaturized integrated diagnostic and therapeutic wearable devices.

The efficacy of hemoglobin spray in wound management: a systematic review and network meta-analysis of comparative studies

Purpose There is no evidence comparing the treatment results of hemoglobin spray and hyperbaric oxygen therapy (HBOT) in chronic wounds. Therefore, we conducted a systematic review and network meta-analysis to explore the efficacy and role of hemoglobin spray in the treatment of chronic wounds. The probabilities of being the best treatment option were estimated and ranked between hemoglobin spray and HBOT. Methods A systematic review and network meta-analysis (NMA) were conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines and PROSPERO number: CRD42020161396. Results A total of 934 studies were identified from PUBMED and SCOPUS databases, and 112 articles were deleted. Among the 24 studies, 16 RCTs and eight cohort studies met our inclusion criteria. In direct meta-analysis, HBOT had higher proportion of wound healing rate than control with pooled risk ratios (RRs) of 1.67 (95%CI: 1.10, 2.52). Hemoglobin spray had a higher wound healing rate than the control, with a pooled odds ratio (OR) of 1.92 (95%CI: 1.35, 2.73). In the network meta-analysis, the probability of being the best treatment was hemoglobin spray, followed by hyperbaric, with surface under the cumulative ranking curve (SUCRAs) of 67.9, and 32.1, respectively. Conclusions Our evidence suggests that the proportion of wound healing in the hemoglobin spray and HBOT groups was higher than that in the control group. A network meta-analysis demonstrated that hemoglobin spray had the highest chance of treatment success. There is a need for further studies using well-designed RCTs and updated meta-analyses to provide enough evidence to compare the effectiveness of hemoglobin spray and HBOT in clinical practice.

Ultrasound, laser and plasma therapy: basic indications for use - application in the therapy of chronic wounds

Ultrasound, laser and plasma therapy: basic indications for use - application in the therapy of chronic wounds

Localized Surface Plasmon Resonance-Enhanced Photocatalytic Antibacterial of In Situ Sprayed 0D/2D Heterojunction Composite Hydrogel for Treating Diabetic Wound.

Chronic diabetic wounds pose significant challenges due to uncontrolled bacterial infections, prolonged inflammation, and impaired angiogenesis. The rapid advancement of photo-responsive antibacterial therapy shows promise in addressing these complex issues, particularly utilizing 2D heterojunction materials, which offer unique properties. Herein, an in situ sprayed Bi/BiOCl 0D/2D heterojunction composite fibrin gel with the characteristics of rapid formation and effective near-infrared activation is designed for the treatment of non-healing diabetes-infected wounds. The sprayed composite gel can provide protective shielding for skin tissues and promote endothelial cell proliferation, vascularization, and angiogenesis. The Bi/BiOCl 0D/2D heterojunction, with its localized surface plasmon resonance (LSPR), can overcome the wide bandgap limitation of BiOCl, enhancing the generation of local heat and reactive oxygen species under near-infrared irradiation. This facilitates bacterial elimination and reduced inflammation, supporting the accelerated healing of diabetes-infected wounds. This study underscores the potential of LSPR-enhanced heterojunctions as advanced wound therapies for chronic diabetic wounds.

Design of a clinical study to demonstrate the therapeutic benefit of another wound treatment product

Due to new legal requirements, a patient-relevant benefit for other wound treatment products (sPW) must be demonstrated through clinical studies if reimbursement at the expense of the statutory health insurance is sought in the non-inpatient sector. An interdisciplinary group with expertise in clinical wound care has developed general recommendations for the design of suitable studies. In addition to regulatory documents, previous studies that have already been recognized as proof of benefit in other areas served as a basis. Randomized controlled trials that cover at least the most common types of chronic wounds (arterial, venous, diabetic or pressure sore) are recommended as the best method for gathering evidence. Despite the heterogeneous etiology of chronic wounds, the results should also be transferable to other wound types. The test intervention does not usually consist of the sPW alone, but of a combined wound treatment that follows a treatment plan that is as clearly defined as possible. In the comparison group, all wound treatment options (besides the sPW) must also be available and used according to a similar predefined treatment plan. Depending on the intended purpose and treatment goal, complete wound closure should, if possible, be recorded as the cardinal - although not always as the primary - endpoint. In justified cases, e.g. in the case of intermediate use as part of phase-appropriate wound therapy for chronic wounds, a significant reduction in the wound area can also be considered for benefit assessment. Quality of life (e.g. pain) can also justify a benefit and can therefore be recorded as a primary outcome parameter in clinical trials. The duration of the clinical trial should be adapted to the central endpoints, the medical or nursing goal of wound care and the intended purpose of the sPW. A benefit does not always arise from microbiological, physiological, laboratory or histological parameters or imaging findings.

Self-Adapting Biomass Hydrogel Embodied with miRNA Immunoregulation and Long-Term Bacterial Eradiation for Synergistic Chronic Wound Therapy.

Chronic wound rescue is critical for diabetic patients but is challenging to achieve with a specific and long-term strategy. The prolonged bacterial inflammation is particularly prevalent in hyperglycemia-induced wounds, usually leading to severe tissue damage. Such a trend could further suffer from an environmental suitability provided by macrophages for persisting Staphylococcus aureus (S. aureus) and even deteriorate by their mutual reinforcement. However, the strategy of both suppressing bacteria growth and immunoreprogramming the inflammatory type of macrophages to break their vicious harm to wound healing is still lacking. Here, a self-adapting biomass carboxymethyl chitosan (CMC) hydrogel comprising immunomodulatory nanoparticles is reported to achieve Gram-negative/Gram-positive bacteria elimination and anti-inflammatory cytokines induction to ameliorate the cutaneous microenvironment. Mechanistically, antibacterial peptides and CMCs synergistically result in a long-term inhibition against methicillin-resistant S. aureus (MRSA) over a period of 7 days, and miR-301a reprograms the M2 macrophage via the PTEN/PI3Kγ/mTOR signaling pathway, consequently mitigating inflammation and promoting angiogenesis for diabetic wound healing in rats. In this vein, immunoregulatory hydrogel is a promising all-biomass dressing ensuring biocompatibility, providing a perspective to regenerate cutaneous damaged tissue, and repairing chronic wounds on skin.

Features of the regulation of reparative processes of chronic wounds in response to the effect of photobiomodulation therapy on a wound defect. Photobiomodulation therapy for chronic wounds.

One of the promising methods of influencing the wound process is photobiomodulation (PBM) therapy. The optimal parameters of PBM therapy have not yet been found because the molecular mechanisms of light interaction with tissue are not fully understood. Studying the influence of PBM of various parameters on the regulation of reparative process- es of chronic wounds using the example of indicators of aggregation activity of platelets, platelet-derived growth factor (PDGF), interleukin-8 (IL-8), and amino-terminal propeptide of type III procollagen (PIIINP) at the remodeling stage. And also the study of the structural and functional features of chronic wound heal- ing in an experiment under various parameters of PBM therapy. Experiments were carried out on Wistar rats. Chronic wounds were simulated. Experimental animals were exposed to PBM at a wavelength of 660 nm and an energy density of 1 J/cm2. In serum, PDGF, IL-8, and PIIINP levels were measured by enzyme-linked immunosorbent assay. The functional activity of platelets was measured using the turbidimetric method. Histological analysis was performed. The work noted the dose-dependent effect of PBM using the example of platelet aggregation at the remodeling stage during the healing of chronic wounds. The use of PBM therapy resulted in increased serum PDGF levels. Histological examination data indicate a positive effect of PBM therapy on the wound healing process. The effectiveness of the use of PBM therapy for the healing of chronic wounds to regulate reparative processes has been proven.

Negative Pressure Wound Therapy for Chronic Wounds.

Chronic wounds, including those caused by venous and arterial insufficiency, diabetic complications, and pressure-induced ulcers, pose significant treatment challenges. Negative pressure wound therapy has been increasingly used for managing these wounds. This treatment aims to promote wound healing, prepare the wound bed for further surgical intervention, minimize the risk of infection, and potentially shorten the time to wound healing. Considering variances in techniques applied in different regions globally, there is an emerging need to comprehensively evaluate the effectiveness of negative pressure wound therapy on chronic wounds. Unfortunately, detailed descriptions of the techniques applied to achieve negative pressure are often lacking in existing literature abstracts, posing challenges for direct comparisons. This review aims to analyze the application of negative pressure wound therapy in the treatment of chronic wounds, summarize its advantages and disadvantages, and further explore the potential value and future research direction of negative pressure wound therapy in the repair of chronic wounds.

Skin-like breathable wound dressings with antimicrobial and hemostatic properties

Wound healing requires a contamination-free, sterile, and breathable environment. However, to develop an ideal wound dressing with all these functionalities simultaneously poses significant challenges. In this study, we designed a wound dressing that mimics the structure of skin with good breathability and protective functions. The wound dressing consists of a hydrophilic Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) membrane coated with zinc oxide nanoparticles and a hydrophobic polyvinylidene fluoride (PVDF) membrane. Meanwhile, plasma treatment was also utilized to bond the two layers, resulting in an enhancement of 60 % in mechanical properties. The crosslinked fibrous membranes exhibited uniform stress distribution when stretching. Due to the unique structures of the wound dressing, it demonstrates wound exudate management, antibacterial functions, and hemostatic properties. The hydrophobic layer guided wound exudate towards the hydrophilic layer and the zinc oxide nanoparticles acted as a barrier against external bacteria and released zinc ions to inhibit bacterial growth in the exudate. Moreover, the water vapor transmission rate (WVTR) was measured to be over 86.55 kg/m2/day, the hemolysis rate was 2.38 %, and an impressive 81.98 % healing rate was recorded during in vitro wound healing. This skin-mimicking wound dressing shows great potential as a promising solution for the therapy of chronic wounds and infections.

A novel conductive microtubule hydrogel for electrical stimulation of chronic wounds based on biological electrical wires

Electrical stimulation (ES) is considered a promising therapy for chronic wounds via conductive dressing. However, the lack of a clinically suitable conductive dressing is a serious challenge. In this study, a suitable conductive biomaterial with favorable biocompatibility and conductivity was screened by means of an inherent structure derived from the body based on electrical conduction in vivo. Ions condensed around the surface of the microtubules (MTs) derived from the cell’s cytoskeleton are allowed to flow in the presence of potential differences, effectively forming a network of biological electrical wires, which is essential to the bioelectrical communication of cells. We hypothesized that MT dressing could improve chronic wound healing via the conductivity of MTs applied by ES. We first developed an MT-MAA hydrogel by a double cross-linking method using UV and calcium chloride to improve chronic wound healing by ES. In vitro studies showed good conductivity, mechanical properties, biocompatibility, and biodegradability of the MT-MAA hydrogel, as well as an elevated secretion of growth factors with enhanced cell proliferation and migration ability in response to ES. The in vivo experimental results from a full-thickness diabetic wound model revealed rapid wound closure within 7d in C57BL/6J mice, and the wound bed dressed by the MT-MAA hydrogel was shown to have promoted re-epithelization, enhanced angiogenesis, accelerated nerve growth, limited inflammation phases, and improved antibacterial effect under the ES treatment. These preclinical findings suggest that the MT-MAA hydrogel may be an ideal conductive dressing for chronic wound healing. Furthermore, biomaterials based on MTs may be also promising for treating other diseases.

M.O.I.S.T. Concept for the Local Therapy of Chronic Wounds: An International Update.

Chronic wounds remain a significant clinical challenge both for those affected and for healthcare systems. The treatment is often comprised and complex. All patients should receive wound care that is integrated into a holistic approach involving local management that addresses the underlying etiology and provides for gold standard therapy to support healing, avoid complications and be more cost effective. There have been significant advances in medicine over the last few decades. The development of new technologies and therapeutics for the local treatment of wounds is also constantly increasing. To help standardize clinical practice with regard to the multitude of wound products, the M.O.I.S.T. concept was developed by a multidisciplinary expert group. The M stands for moisture balance, O for oxygen balance, I for infection control, S for supporting strategies, and T for tissue management. Since the M.O.I.S.T. concept, which originated in the German-speaking countries, is now intended to provide healthcare professionals with an adapted instrument to be used in clinical practice, and a recent update to the concept has been undertaken by a group of interdisciplinary experts to align it with international standards. The M.O.I.S.T. concept can now be used internationally both as an educational tool and for the practical implementation of modern local treatment concepts for patients with chronic wounds and can also be used in routine clinical practice.

Fabrication and Therapeutic Process of a Green Silver-Nanoparticle-Embedded Mucilage Microsphere for Pathogenic-Bacteria-Infected Second-Degree Burn and Excision Wounds.

Multidrug-resistant bacteria are a serious problem in biomedical applications that decrease the wound healing process and increase the mortality rate. Therefore, in this study, we have prepared a green-synthesized silver-nanoparticle-encapsulated mucilage microsphere (HMMS@GSNP) from Hibiscus rosa sinensis leaves and applied it to pathogen-infected burn and excision wounds. Biophysical properties like size, polydispersity index, absorbance capacity, and drug release were measured by different techniques like field-emission scanning electron microscopy, dynamic light scattering, swelling ratio, etc. The strong antibacterial activity of a HMMS@GSNP microsphere was measured by minimum inhibitory concentration assay, minimum bactericidal concentration assay, and agar well diffusion methods. The HMMS@GSNP microsphere enhanced the cell viability, cell proliferation, migration, antioxidant, and antiinflammation activity compared to untreated GSNP and HMMS, as quantified by MTT assay, BrdU assay, scratch wound assay, reactive oxygen species scavenging assay, and Western blot analysis, respectively. In the in vivo experiment, we used a methicillin-resistant Staphylococcus aureus bacteria-infected, burn-and-excision-wound-created male BALB/c mice model. The HMMS@GSNP-treated burn-and-excision-wound-infected mice showed significant results compared to other groups (untreated, Silverex Ionic Gel, AgNO3, HMMS, and GSNP), and the mice tissues were utilized for bacteria count, immunoblot analysis, histological studies, and real-time polymerase chain reaction. Thus, the HMM@GSNP microsphere is an excellent therapeutic material that can be used as a topical agent for the management of chronic wound therapy.

Low-level photodynamic therapy in chronic wounds

BackgroundChronic wounds refer to those that can't reconstruct anatomical and physical functional integrity, and are usually associated with signs of microbial infection. Current therapies include debridement and dressing change, local or systemic application of antibiotics, and medical dressing care, which are not ideal for the healing of chronic wounds. ObjectiveTo explore the efficacy and safety of photodynamic therapy (ALA-PDT) for the treatment of chronic infectious wounds. Materials and methodsALA-PDT was used in ten patients with persistent wound infections and systemic complications who did not respond to conventional treatment. 5 % ALA solution was applied to the wound surface after debridement, incubated for 3 h with light protection, and then irradiated with red light for 20 min. This procedure was repeated every two weeks, and any adverse reactions were recorded. After the end of three treatments, the patients were followed up for 3 months. ResultsPatients who exhibit resistance to traditional therapies demonstrate a favorable therapeutic outcome with ALA-PDT, although complications may impede wound healing. All participants successfully underwent ALA-PDT treatment and subsequent monitoring, with 90 % achieving complete healing. Common adverse reactions to ALA-PDT encompass treatment-related pain, temporary erythema, and swelling, all of which are well-tolerated by patients without enduring severe consequences. ConclusionsALA-PDT proves to be an efficacious intervention for managing chronic wounds, irrespective of the presence of localized infections or systemic complications.

Combination of curcuminoid and collagen marine peptides for healing diabetic wounds infected by methicillin-resistant Staphylococcus aureus

Background and Aim: The high prevalence of diabetes mellitus in Indonesia indirectly reflects the high risk of developing chronic wounds that are susceptible to infection. Methicillin-resistant Staphylococcus aureus (MRSA) is an infectious pathogen that is resistant to various antibiotics. Therefore, antibiotic therapy is ineffective enough to treat chronic hyperglycemic wounds caused by MRSA infection. Curcuminoids have anti-inflammatory and antibacterial effects by inhibiting the enzymatic pathways involved in the pathogenesis of inflammation. Collagen is a tissue regeneration inducer. The combination of these two ingredients is expected to be an alternative therapy for MRSA-infected hyperglycemic chronic wounds without the risk of antibiotic resistance. The aim of this study was to investigate the efficacy of hydrolacin-gel in wound healing and inhibiting the growth of MRSA bacteria, as well as to determine the optimal concentration of curcuminoids combined with collagen marine peptides (CMPs). Materials and Methods: Hydrolacin-gels were prepared by homogenizing curcuminoid nanoemulsions and CMPs. The evaluation of preparation includes stability tests and antibacterial activity tests. Wound diabetic mice were treated with various combinations of curcuminoid and CMPs. Wound healing was observed based on malondialdehyde levels as a marker of oxidative stress and histopathological changes in the skin wound. Results: Hydrolacin-gel was formulated by combining curcuminoid nanoemulsion (more water soluble) and CMPs, with the ratio of formula 1 (1:2, curcuminoid 43.3 mg and CMPs 5.58 mg), formula 2 (1:1, curcuminoid 86.8 mg and CMPs 3.72), and formula 3 (2:1, curcuminoid 130.2 mg and CMPs 1.87 mg) calculated based on the effective dose of curcuminoid 200 mg/kg body weight (BW) and CAMPs 0.9 g/kg BW. Hydrolacin-gel had a potential antibacterial activity against MRSA. Hydrolacin-gel induced wound tissue repair and reduced oxidative stress caused by inflammation in diabetic-infected MRSA. Hydrolacin-gel could be used for healing MRSA-infected diabetic wounds, especially formula 3 with the ratio of curcuminoid: CMPs = 2:1. Conclusion: Hydrolacin-gel combining curcuminoid nanoemulsion and CMPs effectively inhibited the inflammatory process and increased re-epithelialization in MRSA-infected diabetic wound healing. Hydrolacin-gel with curcuminoid (130.2 mg) and CMPs (1.87 mg) at a concentration ratio of 2:1 appeared to be the best formula against MRSA infection in diabetic wounds. Keywords: collagen marine peptides, curcuminoids, diabetic, methicillin-resistant Staphylococcus aureus, wound.

A smart band-aid with temperature and reactive oxygen species dual-responsiveness for synergistic mechanical and pharmacological therapy of chronic wounds

In this study, a dual-responsive multifunctional band-aid comprising a force-induced shrinkage layer and a drug-treated layer has been developed, characterized by its on-demand drug release. Evaluated through the pig skin the force-induced shrinkage layer facilitates active wound closure by forming stable adhesion to the skin. Afterward, the layer could provide mechanical force simulating the embryonic skin in response to temperature changes. Concomitantly, confronting the increased levels of reactive oxygen species (ROS) at the wound site, the drug-treated layer made of an ROS-responsive hydrogel, promptly releases zinc oxide (ZnO) and catalase (CAT) to exert antibacterial and anti-inflammatory stress effects, ultimately accelerating the healing process of chronic wounds. More important, this versatile hydrogel-based band-aid demonstrates remarkable efficacy in both bacteria-infected rat wounds and rat tooth extraction wounds. Overall, the versatility of this approach presents a comprehensive and convenient strategy for the treatment of clinical chronic wounds.

Multifunctional PDA/ZIF8 based hydrogel dressing modulates the microenvironment to accelerate chronic wound healing by ROS scavenging and macrophage polarization

An ideal wound dressing has both efficient antimicrobial and anti-inflammatory properties, as well as the potential to regulate the immune microenvironment for the treatment of chronically infected wounds. Herein, a novel multifunctional hydrogel wound dressing (HPZ8) was developed for wound healing by incorporating polydopamine Zeolite Imidazole Framework 8 (PDA-ZIF8) nanoparticles into a dynamic cross-linked network consisting of hydrazide-modified hyaluronic acid (HA-CDH) and oxidized hyaluronic acid (HA-CHO). The results suggested that the HPZ8 hydrogel could be injected into the wound to form a barrier, facilitating tissue adhesion and rapid hemostasis. After loaded with PDA-ZIF8 nanoparticles, the hydrogel exhibited excellent antioxidant and photothermal antimicrobial properties, which could effectively scavenge ROS, reduce oxidative stress and eliminate bacterial infections. Especially, near-infrared (NIR) irradiation strengthened the photothermal therapy (PTT). Besides, HPZ8 hydrogel could release zinc ions to promote cell migration, angiogenesis and M2 polarization of macrophages, accelerating macrophage transition from inflammation to proliferation stages, thus promoting infected wound healing. Therefore, the HPZ8 multifunctional hydrogel dressing has application prospects for the therapy of chronic infected wounds.