Chronic wounds

Development of an aminoguanidine hybrid hydrogel composites with hydrogen and oxygen supplying performance to boost infected diabetic wound healing

Diabetic wounds tend to develop into non-healing wounds associated with a complex inflammatory microenvironment of uncontrollable bacterial infection, reactive oxygen species (ROS) accumulation, and chronic hypoxia. This study developed a multifunctional hydrogel system by integrating aminoguanidine and hydrogen and oxygen gas-release nanoparticles (PAP NPs) into phenylboronic acid-modified quaternized chitosan and an oxidized dextran network. Hollow mesoporous Prussian blue (HPB) nanozymes with superoxide dismutase- and catalase-like activities are promising bioreactors for simultaneously alleviating ROS accumulation and hypoxia by converting elevated endogenous hydrogen peroxide (H2O2) into oxygen in diabetic wounds. Simultaneously, incorporating ammonia borane (AB)-loaded HPB NPs served as a source of hydrogen, further reducing ROS overproduction and modulating pro-inflammatory cytokine responses. Aminoguanidine in the hydrogel network inhibits the formation of advanced glycation end products (AGEs), inhibiting skin cell apoptosis and promoting their proliferation and migration. Moreover, the hydrogel exhibited significant mechanical characteristics and self-healing capacity owing to the Schiff base and phenylboronate ester linkages. Incorporating PAP NPs into the hydrogel produced an exceptional photothermal response, effectively eradicating bacteria with a mortality rate exceeding 95 % within 10 min and protecting the wound from potential infections. In vivo studies demonstrated that PAP@Gel significantly accelerated the healing of infected diabetic wounds by mitigating oxidative stress, enhancing oxygenation, inhibiting inflammation and AGE formation, and reversing bacterial infections. This study highlights a promising nanomedicine approach for designing future diabetic wound dressings, providing a novel strategy for catalytic ROS scavenging and synergistic hydrogen and oxygen therapies.

Curcumin nanoparticles loaded in a bioengineering and biodegradable silk-hyaluronan scaffold triggered wound healing by regulating inflammation and accelerating proliferation in a diabetic rat model

The complex causes of diabetic wounds require a combined strategy for effective treatment. Herein we investigated whether bioengineering and biodegradable silk-hyaluronan (SH) scaffold incorporated with curcumin nanoparticles (CN) could promote wound repairing in diabetic rats. Forty-five diabetic animals were randomly divided into the control group, SH group, and CN-incorporated SH (SCN) group. Sampling took place on days 4 and 8 for additional evaluations. Evaluations indicated that the parameters related to regeneration, including wound closure, fibroblasts and blood vessel counts, collagen density, and tensile strength, as well as concentration levels of TGF-β and VEGF in both treatment groups were considerably greater than those of the control group, and these changes were more obvious in the SCN ones. This is while the number of neutrophils and macrophages, and the concentration levels of TNF-α and IL-1β decreased more notably in the SCN group than the other groups. In general, these results indicated that using the complementary or synergistic impacts of curcumin nanoparticles and SH could be a promising approach to accelerate diabetic wound healing.

Fabrication of curcumin‑incorporated poly glycerol sebacate/poly lactide acid (PGS/PLA) hydrogel to enhance full‑thickness wound healing in diabetic rats

New wound dressings with therapeutic benefits are consistently being developed to enhance the wound healing process. In present study, a biocompatible wound dressing was fabricated using curcumin- incorporated poly glycerol sebacate/poly lactide acid (PGS/PLA) hydrogel to promote diabetic wound healing in rats. A total of 60 diabetic rats were randomly planned to four groups: the control group, PGS/PLA group, curcumin group, and PGS/PLA+Curcumin group. Sampling occurred on days 7 and 14 for further evaluations. Our findings revealed that the rates of wound healing, dimensions and thickness of newly created epidermis, counts of blood vessels, collagen accumulation, levels of TGF-β and VEGF cytokines, and wound robustness were notably greater in the treated groups versus the control group, with these effects being more significant in the PGS/PLA+Curcumin group. In contrast to the other groups, the PGS/PLA+Curcumin group exhibited a more significant reduction in the inflammatory and apoptotic cell counts, and concentration levels of IL-1β and TNF-α cytokines. In conclusion, it was established that the partnership of PGS/PLA and curcumin greatly improves healing of diabetic wounds.

Cryopreservable, scalable and ready-to-use cell-laden patches for diabetic ulcer treatment

Stem cell-laden hydrogel patches are promising candidates to treat chronic ulcers due to cells' long-lasting and dynamic responses to wound microenvironment. However, their clinical translations are prohibited by the cryopreservation difficulty due to their weak mechanical strength and slow biotransport capability, and by the morphological mismatch between clinical ulcers and pre-fabricated patches. Here we report a stem cell-laden alginate-dopamine hydrogel patch that can be readily cryopreserved, processed, and scaled toward clinical usages. This cell-hydrogel patch not only maintains cell viability and structure integrity during cryopreservation, but also can be directly utilized without centrifugation or incubation post cryopreservation. In addition, this tissue-adhesive hydrogel patch enables close wound contact and fast cellular response, and its scalable and flexible structure enables assembly for large or irregularly shaped ulcers. Therefore, it accelerates ulcer healing and reduces scar formation via continuous, versatile, self-adjusting paracrine of imbedded, cryopreserved stem cells. These findings highlight its potential for scalable clinical applications in chronic wound management and pave the way for broader adoption of ready-to-use regenerative therapies.

Antheraea pernyi silk nanofibrils with inherent RGD motifs accelerate diabetic wound healing: A novel drug-free strategy to promote hemostasis, regulate immunity and improve re-epithelization

The chronic inflammation and matrix metalloprotease (MMP)-induced tissue degradation significantly disrupt re-epithelization and delay the healing process of diabetic wounds. To address these issues, we produced nanofibrils from Antheraea pernyi (Ap) silk fibers via a facile and green treatment of swelling and shearing. The integrin receptors on the cytomembrane could specifically bind to the Ap nanofibrils (ApNFs) due to their inherent Arg-Gly-Asp (RGD) motifs, which activated platelets to accelerate coagulation and promoted fibroblast migration, adhesion and spreading. These degradable nanofibrils served as effective competitive substrates to reduce MMP-induced tissue degradation. ApNFs and their enzymatic hydrolysates could modulate macrophage polarization due to their RGD motifs. RNA sequencing further revealed that ApNFs treatment activated the JAK2-STAT5b and PI3K-Akt signaling pathways while suppressed the NF-κB, IL-17 and TNF signaling pathways in macrophages. The full-thickness skin wound experiments confirmed that ApNFs significantly accelerated wound healing in both diabetic and non-diabetic rats. Notably, in diabetic wound, ApNFs and their enzymatic hydrolysates polarized the accumulated M1-type macrophages into M2-type, which promoted the wound to get rid of the inflammatory stage and transition to the following proliferative stage, improving the wound healing percentage on day 14 from 74.9 % to 93.2 % by facilitating collagen deposition, angiogenesis and re-epithelization. These results demonstrate that ApNFs are promising drug-free diabetic wound dressings with favorable inherent immunoregulatory properties for biomedical translation.

Hesperidin-loaded self-assembled supramolecular hydrogel based on quaternized chitosan as efficient photothermal antibacterial dressing for MRSA-infected wound healing

The management of infected chronic wounds is one of the urgent challenges. Herein, a hesperidin (Hes)-loaded self-assembled supramolecular hydrogel based on quaternized chitosan (CQHP) has been developed as an efficient photothermal antibacterial dressing for MRSA-infected wound healing. Specifically, CQHP hydrogels fabricated through the dynamic noncovalent interactions among CM-β-CD grafted QCS, Hes, proline and Fe3+, exhibited injectable and self-healing behaviors, along with adhesion, antioxidant, hemostatic and protein adsorption performance, satisfying the essential feature as chronic wound dressing. Of note, superior photothermal effect generated from the Hes-Fe3+ has been demonstrated, which endowed the CQHP hydrogels effectively and rapidly eliminate the E. coli, S. aureus and MRSA through photothermal therapy, thereby avoiding the use of antibiotics or photothermal conversion nanomaterials in hydrogels and substantially reducing the biological toxicity. Furtherly, sustained antibacterial performance in the absence of NIR can be achieved through the inherent antibacterial activities of Hes. Importantly, the developed CQHP hydrogels significantly promoted the closure of acute full-thickness scratch wounds, and exhibited remarkable better therapeutic effect on MRSA-infected wound than commercial 3M transparent film, by efficiency and sustained antibacterial activity, reducing inflammation, enhancing angiogenesis and collagen deposition, highlighting its promising application in the MRSA-infected wound healing with high efficiency, quality and security.

Polyaminoglycoside nanosystem expressing antimicrobial peptides for multistage chronic wound management

Chronic wounds are difficult to heal due to pathogenic microbial colonization and dysregulation of healing cascades, necessitating novel therapeutic strategies. This study developed a multifunctional nanosystem by integrating the antimicrobial peptide LL37 with cationic polyaminoglycoside (SS-HPT), constructing a self-sustaining "AMP factory" to achieve multi-stage modulation of the wound healing. Validation through cell-level experiments and in vivo dual models (mechanical injury and bacterial infection) in immunocompromised rats demonstrated the system's unique dual intracellular-extracellular pathogen-killing capability, significantly accelerating the wound healing process. Transcriptomic analysis revealed that its mechanism involves the dual effects of suppressing pro-inflammatory factor expression and activating tissue repair pathways. Histological evidence confirmed that the system promotes angiogenesis, enhances re-epithelialization rates, and guides orderly collagen fiber deposition. This nanosystem, combining efficient AMP delivery and integrated therapeutic strategies, achieves three-dimensional synergy in microbial clearance, immune microenvironment regulation, and tissue matrix remodeling, providing theoretical and technical foundations for a paradigm shift in chronic wound treatment.

Stimuli-responsive hydrogel with spatiotemporal co-delivery of FGF21 and H₂S for synergistic diabetic wound repair

Chronic diabetic wounds pose significant clinical challenges due to persistent inflammation, impaired angiogenesis, and disrupted cellular homeostasis. To address these multifactorial barriers, we engineered an injectable, biodegradable, and biocompatible methylated silk fibroin (SilMA) hydrogel system co-loaded with cobalt sulfide (CoS) and fibroblast growth factor 21 (FGF21), designed for on-demand therapeutic release. In the acidic microenvironment characteristic of the inflammatory phase of diabetic wounds, the hydrogel rapidly releases hydrogen sulfide (H₂S) and Co2+ ions, mitigating inflammation and exerting antibacterial effects. Subsequently, during the proliferative and remodeling phases, sustained release of FGF21 promotes cellular proliferation, angiogenesis, and enzymatic homeostasis, thereby accelerating wound healing. Mechanistic studies reveal that the hydrogel facilitates M2 macrophage polarization and activates the JAK/STAT signaling pathway, leading to upregulation of vascular endothelial growth factor (VEGF). Additionally, it enhances antioxidant enzyme activities (superoxide dismutase, catalase, glutathione) while suppressing pro-oxidant enzymes (NADPH oxidase, lipoxygenase, cyclooxygenase). In vivo studies using a diabetic mouse model demonstrate that this dual-functional hydrogel significantly improves wound closure rates and tissue regeneration. These findings suggest that the SilMA-FGF21/CoS hydrogel represents a promising therapeutic strategy for the management of diabetic wounds.

Injectable nanocomposite hydrogels for targeted intervention in cancer, wound healing, and bone and myocardial tissue engineering

Despite current medicine's fast-paced advances, many acute and chronic illnesses still lack truly effective and safe therapies. Cancer treatments often lead to off-target healthy tissue damage and poor therapeutic outcomes, wound standard treatments generally demonstrate poor healing efficacy and increased susceptibility to infection, and bone tissue engineering and myocardial tissue engineering can result in immunological rejection and limited availability. To tackle these issues, injectable hydrogels have emerged, and through the incorporation of nanoparticles, nanocomposite hydrogels have appeared as versatile platforms, offering improved biocompatibility, mechanical strength, stability, and precise controlled drug release, as well as targeted delivery with increased drug retention at the site of action, reducing systemic drug distribution to non-target sites. With the ability to deliver a diverse range of therapeutic entities, including low molecular weight drugs, proteins, antibodies, and even isolated cells, injectable nanocomposite hydrogels have revolutionized current therapies, working as multifunctional platforms capable of improving efficacy and safety in cancer treatment, including in chemotherapy, immunotherapy, photothermal therapy, magnetic hyperthermia, photodynamic therapy, chemodynamic therapy, radiotherapy, molecularly targeted therapy, and after tumor surgical removal, and in general, chronic diabetic or tumor-induced wound healing, as well as in bone tissue engineering and myocardial tissue engineering. This review provides a thorough summary and critical insight of current advances on injectable nanocomposite hydrogels as an innovative approach that could bring substantial contributions to biomedical research and clinical practice, with a focus on their applications in cancer therapy, wound healing management, and tissue engineering.

Development of a bioactive hyaluronic acid hydrogel functionalised with antimicrobial peptides for the treatment of chronic wounds

Chronic wounds present significant clinical challenges due to delayed healing and high infection risk. This study presents the development and characterisation of acrylated hyaluronic acid (AcHyA) hydrogels functionalised with gelatin (G) and the antimicrobial peptide (AMP) PP4-3.1 to enhance cellular responses while providing antimicrobial activity. AcHyA-G and AcHyA-AMP hydrogels were formed via thiol-acrylate crosslinking, enabling in situ AcHyA hydrogel formation with stable mechanical properties across varying gelatin concentrations. Biophysical characterisation of AcHyA-G hydrogels showed rapid gelation, elastic behaviour, uniform mesh size, and consistent molecular diffusion across all formulations. Moreover, the presence of gelatin enhanced stability without affecting the hydrogel's degradation kinetics. AcHyA-G hydrogels supported the adhesion and spreading of key cell types involved in wound repair (dermal fibroblasts and endothelial cells), with 0.5% gelatin identified as the optimal effective concentration. Furthermore, the conjugation of the AMP conferred bactericidal activity against Staphylococcus aureus and Escherichia coli, two of the most prevalent bacterial species found in chronically infected wounds. These results highlight the dual function of AcHyA-AMP hydrogels in promoting cellular responses and antimicrobial activity, offering a promising strategy for chronic wound treatment. Further in vivo studies are needed to evaluate their efficacy, including in diabetic foot ulcers.

Programmable hierarchical hydrogel dressing for sequential release of growth factor and DNase to accelerate diabetic wound healing

Dysregulation of growth factor expression causes impaired healing of diabetic foot ulcer (DFU). Platelet-derived growth factor (PDGF)-containing gel has been clinically applied for topical treatment of DFU. Recruitment of neutrophils stimulated by PDGF favors the wound healing of DFU. However, overactivation of neutrophils induced by hyperglycemia causes massive generation and long-term persistence of neutrophil extracellular traps (NETs), ultimately leading to unexpected skin damage and delayed wound repair. Here, we engineer a hierarchically-assembled hydrogel to achieve local release of the growth factor, PDGF-BB and the NET scavenger, deoxyribonuclease (DNase) I with distinct kinetics for enhanced healing of DFU. The hydrogel is constructed by crosslinking of anti-bacterial quaternized chitosan and hypochlorite-degradable nanogel via a copper-free click reaction, in which PDGF-BB is loaded in the hydrogel matrix while DNase I is encapsulated in the inner nanogel. Programmable release of combinatorial therapeutics is implemented by the hydrogel in response to the wound microenvironment. We show that the hierarchical hydrogel co-loaded with PDGF-BB and DNase I promotes neutrophil recruitment, increases endothelial cell migration, degrades excess NETs, and prevents wound infection for accelerating the wound closure in the diabetic mouse wound models.

Pitaya stem polysaccharide promotes wound healing by modulating macrophage polarization via single-cell RNA sequencing evidence

Hyperactivation of M1 macrophages or delayed macrophage M2/M1 polarization during wound healing is a major obstacle to wound healing. Polysaccharide, as a biomaterial, has shown great potential and advantages in the field of wound dressings, but little is known about the role of polysaccharide (PSP) in wound healing. The aim of this study was to investigate the promotional effect of PSP on wound healing through its effect on macrophage M2/M1 polarization. The results showed that PSP treatment polarized the macrophage population toward an M2 phenotype, significantly accelerating wound closure in vivo, as evidenced by increased levels of collagen deposition, decreased levels of pro-inflammatory cytokines (INOS, IL-6, and IL-1β), and increased expression of CD31 (an angiogenic marker) and Ki67 (a cell proliferation marker). Functional changes in skin macrophages during wound healing were analyzed using single-cell RNA sequencing (scRNA-seq). The results highlighted a unique transcriptional signature associated with PSP-induced polarization of M2 macrophages. Moreover, PSP was found to upregulate the PI3K/Akt signaling pathway, which is crucial for cell survival, migration, and tissue repair. These results reveal that PSP can promote skin wound healing, emphasizing its potential as a natural product for treating skin wounds.

Electroactive Electrospun Nanofibrous Scaffolds: Innovative Approaches for Improved Skin Wound Healing

The incidence and burden of skin wounds, especially chronic and complex wounds, have a profound impact on healthcare. Effective wound healing strategies require a multidisciplinary approach, and advances in materials science and bioengineering have paved the way for the development of novel wound healing dressing. In this context, electrospun nanofibers can mimic the architecture of the natural extracellular matrix and provide new opportunities for wound healing. Inspired by the bioelectric phenomena in the human body, electrospun nanofibrous scaffolds with electroactive characteristics are gaining widespread attention and gradually emerging. To this end, this review first summarizes the basic process of wound healing, the causes of chronic wounds, and the current status of clinical treatment, highlighting the urgency and importance of wound dressings. Then, the biological effects of electric fields, the preparation materials, and manufacturing techniques of electroactive electrospun nanofibrous (EEN) scaffolds are discussed. The latest progress of EEN scaffolds in enhancing skin wound healing is systematically reviewed, mainly including treatment and monitoring. Finally, the importance of EEN scaffold strategies to enhance wound healing is emphasized, and the challenges and prospects of EEN scaffolds are summarized.

Integrated insights into gene expression dynamics and transcription factor roles in diabetic and diabetic-infectious wound healing using rat model

BACKGROUND

Diabetic or diabetic infectious wounds pose a global challenge, marked by delayed healing and high amputation/mortality rates. This study of participating transcriptomes and their regulators unveils critical alterations.

METHODS

Transcriptome data from GEO analyzed DEGs in diabetic foot ulcers vs. controls using RNA-Seq, limma, STRINGdb, Cytoscape, and clusterProfiler for PPI networks and functional enrichment. TRRUST database was used to predict transcriptional factors (TFs). Adverse molecular pathology in different models of wounds (non-diabetic, acute diabetic, diabetic infectious wounds) was validated by RT-PCR, Western blotting, oxidative stress markers, cytokines, and histological analysis.

RESULTS

RNA-Seq dataset 'GSE199939' was analyzed after normalization to identify DEGs (total 47 DEG, 31 upregulated, 16 downregulated) in diabetic wound healing using limma. PPI networks revealed seven hub genes which were further processed for functional enrichment and highlighted oxidative stress, ECM remodeling, AGE-RAGE, and IL-17 signaling in diabetic wound pathology. Additionally, 17 key TFs were identified as hub gene regulators. The healing rate was significantly impaired in diabetic wounds, with delayed contraction, elevated pro-inflammatory cytokines, oxidative stress, reduced anti-inflammatory cytokines, antioxidants, angiogenesis, collagen deposition, and re-epithelialization. Further, RT-PCR and Western blot analysis validated the expression of target genes including the overexpression of HSPA1B, FOS, and down-expression of SOD2, COL1A1, and CCL2, whereas TFs including upregulation of RELA, NFKB1, STAT3, and downregulation of SP1 and JUN in diabetic and diabetic infectious wounds.

CONCLUSION

Molecular analyses reveal disrupted oxidative stress, ECM remodeling, and inflammatory signaling in diabetic and diabetic infectious, emphasizing impaired healing dynamics and identifying therapeutic targets.

Sound Wave-Activated Self-Powered Adhesive Dressing for Accelerated Wound Healing

Self-powered wound dressings are effective in treating chronic wounds because of their low toxicity and convenience. However, current self-powered dressings rely on the bending movements of the skin or additional large ultrasonic devices. Herein, a flexible adhesive self-powered wound dressing (FASW) that promotes skin regeneration through daily sound wave driving without relying on skin bending or external sound devices is proposed. The FASW dressing consists of a bioadhesive film (BAF), a unidirectional fluorinated conductive film (UFCF), and a liquid metal (LM) interlayer. Benefiting from the cross-linking of chitosan, the dressing exhibits excellent properties, such as biocompatibility, stretchability, tissue adhesion, and recyclability. In vivo experiments show that the FASW dressing reduced inflammation and stimulated hair follicle regeneration. This wound dressing utilizes previously overlooked natural energies for the treatment of chronic wounds, thereby enhancing the therapeutic effect of traditional self-powered dressings on individuals with movement disorders.

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

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

Efficacy of continuous topical oxygen therapy in hard-to-heal wounds in Colombia: a retrospective analysis

OBJECTIVE

To evaluate the use of continuous topical oxygen therapy (cTOT) in hard-to-heal or chronic wounds in Colombia, South America.

METHOD

This multicentre, retrospective analysis studied the efficacy of treating hard-to-heal wounds using a cTOT device in patients over a 3-6-month period. Data were collected retrospectively from patient records. Descriptive statistics were used to summarise the characteristics of the patient population, types of wounds and treatment outcomes. Patients were divided into two groups: a continuous cTOT-treated group (n=47) and a discontinuous cTOT-treated group (n=22). The duration of treatment and wound size reduction were compared. Changes in pain medication usage and the incidence of infections were also analysed.

RESULTS

A total of 69 patients were included in the analysis. Complete healing was achieved in 64% of the continuous cTOT-treated group and 36% of the discontinuous cTOT-treated group, with most patients being pain-free and not requiring medication after treatment.

CONCLUSION

The results of this study suggest the benefits of cTOT over traditional treatments in accelerating wound healing and reducing pain, medication necessity and wound infection.

Green synthesis of a lactoferrin-infused silver nanoparticle gel for enhanced wound healing

The study analyzed the benefits of nano-silver (AgNPs) in reducing side effects and enhancing efficacy, highlighting the advantages compared to silver ions. The study examined the production of AgNPs-lactoferrin complexes (AgNPs-LTF) using bovine lactoferrin (LTF) at 1, 2, and 4 mM concentrations. The objective was to create an AgNPs-LTF gel with Carbopol as the base and assess its effectiveness in enhancing wound healing in rats. UV-Vis, PL, FTIR, and XRD analyses confirmed the synthesis of AgNPs. Microscopic examinations (TEM and SEM) showed mainly spherical AgNPs in the AgNPs-LTF samples, with diameters between 11 and 27 nm. The AgNPs-LTF gel with biologically processed AgNPs demonstrated effective infection control and enhanced wound healing outcomes. In Sprague-Dawley rats, the 4 mM AgNPs-LTF gel demonstrated significant wound closure, achieving complete closure by day 10, exceeding the healing rates of both the LTF and control groups. The AgNPs-LTF complex demonstrated high robustness and exceeded the performance of native LTF, exhibiting similar toxicity levels to AgNPs. The study shows the effectiveness of AgNPs-LTF gel in wound treatment, indicating its potential as a viable treatment option.

Advances in Designer Materials for Chronic Wound Healing

Significance: Nonhealing or chronic wounds represent a significant and growing global health concern, imposing substantial burdens on individuals, health care systems, and economies worldwide. Although the standard-of-care treatment involves the application of wound dressings, most dressing materials are not specifically designed to address the pathological processes underlying chronic wounds. This review highlights recent advances in biomaterial design tailored to chronic wound healing. Recent Advances: Chronic wounds are characterized by persistent inflammation, impaired granulation tissue formation, and delayed re-epithelialization. Newly developed designer materials aim to manage reactive oxygen species and extracellular matrix degradation to suppress inflammation while promoting vascularization, cell proliferation, and epithelial migration to accelerate tissue repair. Critical Issues: Designing optimal materials for chronic wounds remains challenging due to the diverse etiology and a multitude of pathological mechanisms underlying chronic wound healing. While designer materials can target specific aberrations, designing a materials approach that restores all aberrant wound-healing processes remains the Holy Grail. Addressing these issues requires a deep understanding of how cells interact with the materials and the complex etiology of chronic wounds. Future Directions: New material approaches that target wound mechanics and senescence to improve chronic wound closure are under development. Layered materials combining the best properties of the approaches discussed in this review will pave the way for designer materials optimized for chronic wound healing.

Multifunctional PdH-hydride MOFs for synergistic hydrogen and photothermal antibacterial therapy in accelerated wound healing

Introduction

The growing threat of bacterial infections poses a critical challenge to public health, underscoring the urgent need for innovative antibacterial agents and therapeutic strategies. In response, we have developed a multifunctional nanoplatform based on palladium-hydride metal-organic frameworks (P(H)ZPAg) for synergistic hydrogen and photothermal antibacterial therapy.

Methods

This nanoplatform integrates palladium hydride (PdH) encapsulated within a zeolitic imidazolate framework (ZIF-8), surface modification with polydopamine (PDA), and in situ generation of silver nanoparticles (Ag NPs) to achieve enhanced antibacterial efficacy. Comprehensive characterization was performed to assess hydrogen release kinetics, photothermal performance, and silver-mediated bactericidal activity. The therapeutic potential of P(H)ZPAg was further evaluated in vivo using a Staphylococcus aureus-infected rat wound model.

Results

The P(H)ZPAg nanoplatform demonstrated a successful combination of hydrogen release, photothermal conversion, and silver ion-based antibacterial mechanisms. In vitro assays revealed potent synergistic antibacterial effects against both Escherichia coli and Staphylococcus aureus. In vivo studies showed that treatment with P(H)ZPAg nanoparticles significantly enhanced wound healing and bacterial clearance compared to control groups.

Discussion

These findings highlight the potential of combining hydrogen therapy, photothermal therapy, and silver ion release within a single nanoplatform to markedly improve antibacterial outcomes. This study presents a promising strategy for the development of multifunctional nanotherapeutics, offering a novel and effective approach for managing topical bacterial infections and promoting wound healing.

A Fully Integrated Wearable Biomimetic Microfluidic Wound Tracker for In Situ Dynamic Monitoring of Wound Exudate Oxygen

Wearable wound exudate sensors hold great promise for providing dynamic measurements of valuable biomarkers. However, no existing sensors are able to achieve the fully integrated, skin-on, and dynamic detection of raw wound exudate oxygen (O2), which is closely related to wound conditions and also essential for wound healing. Here, we report a fully integrated wearable biomimetic microfluidic wound tracker, capable of skin-on biomimetic microfluidic wound exudate sampling, dynamic monitoring of wound exudate O2 in addition to wound exudate uric acid, lactate, pH, and temperature, and wireless control through the seamless integration of specially designed microfluidic, sensing, and electronic modules. We test the performance of the device in both bacterium-inoculated and uninoculated wounds using mouse models. We further assess its potential for wound management in the healing process of infected diabetic mouse wounds through controlled experiments related to local hyperbaric O2 treatment.

The effect of blue and green light on human umbilical cord mesenchymal stem cells for promoting proliferation and wound healing

Photobiomodulation (PBM) has been widely utilized in regenerative medicine, including dermatology, dentistry, and neurology. However, the optimal energy density of PBM for human umbilical cord mesenchymal stem cells (hUC-MSCs) remains underexplored, hindering its development and potential clinical application. This study aims to identify the optimal wavelength and irradiation fluence for promoting the proliferation of hUC-MSCs by comparing the effects of different wavelengths and irradiation fluences. Our results show that green light enhances the anti-inflammatory properties of hUC-MSCs, with the 76s being the most effective in inhibiting IL-6 and GM-CSF. Blue light with 38 s is more effective in promoting angiogenesis, significantly increasing the mRNA and protein secretion of VEGF, HGF, and FGF2 compared to the non-irradiated group. The peak secretion times varied, with VEGF and FGF2 peaking at 72 h and HGF at 24 h. RNA-Seq confirms the significant roles of blue and green light in inhibiting epithelial-mesenchymal transition and inflammation. In vitro co-culture models and conditioned media experiments validate these anti-inflammatory effects. These findings have important implications for accelerating the clinical application of stem cell therapies and provide new references for PBM use in hUC-MSCs.

10-Methoxy-leonurine accelerated wound healing through ErbB4/PI3K-AKT pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurusjaponicus Houtt., commonly known as motherwort, has been used in traditional Chinese medicine to treat trauma and wound infections historically. However, the main compounds responsible for promoting wound healing need to be identified and explained fully.

AIM OF THE STUDY

To investigate the wound healing effect of 10-methoxy-leonurine (MN) and explore its mechanism.

MATERIALS AND METHODS

Following the UHPLC/Q-TOF-MS analysis of L. japonicus, the phytochemical isolation was carried out, and then the effect of isolated compounds in promoting the proliferation of human skin fibroblasts (HSF) was screened. Additionally, scratch and 5-ethynyl-2'-deoxyuridine assay in HSF were further adopted to support the effects of MN in vitro. A rat model with full-thickness skin wounds was used to verify in vivo by hematoxylin and eosin staining, Masson's trichrome and immunohistochemistry. Furthermore, network pharmacology and molecular docking were performed to predict the potential pathway, which were subsequently validated by cell cycle and RT-qPCR.

RESULTS

A total 11 compounds were isolated, in which MN exhibited the most significant bioactivity in promoting HSF proliferation and migration. Moreover, the wound healing rates in low (10 μg/mL) and high dose (50 μg/mL) of MN groups reached 93.9 % and 94.5 %, respectively, which was better than basic fibroblast growth factor (bFGF) 89.4 %. Additionally, the epithelial thickness, collagen Ⅰ deposition and α-smooth muscle actin expression were enhanced and the proportion of HSF cells in the S phase of the cell cycle was increased. Network pharmacological and molecular docking analysis suggested ErbB pathway was involved in the regulation of wound healing by MN, which was further supported by the up-regulation of Erbb4, Stat5, Pi3k, Akt and mTOR mRNA levels.

CONCLUSION

MN showed potent effect on wound healing by regulating ErbB4/PI3K-AKT pathway, even better than bFGF.

Development of a Self-Healing, Tissue-Adhesive, and Bacteriostatic Guar Gum-Based Hydrogel for Enhanced Wound Healing and Tissue Regeneration

A guar gum (GG)-grafted-(polydimethylamino-co-polyacrylamido sulfonic acid) [GG-g-(PDMAEA-co-PAMPS)] hydrogel was developed as a promising material for wound dressings. The hydrogel was synthesized by grafting poly(dimethylaminoethacrylate) (PDMAEA) and poly(acrylamidopropyl sulfonic acid) (PAMPS) onto guar gum (GG), and its structure was confirmed by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses. Rheological assessments demonstrated its mechanical robustness and self-healing properties while swelling studies revealed pH-sensitive behavior. Biocompatibility was confirmed through cell viability assays, showing minimal cytotoxicity and the hydrogel exhibited a bacteriostatic effect against Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis. In a rat full-thickness chronic wound model, the hydrogel significantly accelerated wound healing, enhanced collagen deposition, reduced inflammation, and promoted angiogenesis. These results underscored the potential of the GG-g-(PDMAEA-co-PAMPS) hydrogel as an effective solution for chronic wound management.

A microfluidic wearable device for wound exudate management and analysis in human chronic wounds

Chronic wounds are a major global health challenge associated with substantial economic burden and a negative impact on patient quality of life. Real-time analysis of biomarkers like reactive oxygen and nitrogen species could guide treatment, but existing systems lack the capacity required for continuous monitoring. Wound exudate is secreted slowly and has a complex composition, making efficient fluid collection and real-time analysis challenging. To address these issues, we introduce iCares, a wearable device for wound exudate management and continuous in situ analysis of wound biomarkers. iCares contains a flexible nanoengineered sensor array that measures reactive species such as NO, H2O2, and O2, along with pH and temperature, providing multiparameter data to inform wound status. The device features pump-free triad microfluidic modules with a superhydrophobic-superhydrophilic Janus membrane, bioinspired wedge channels, and three-dimensional graded micropillars for efficient unidirectional exudate collection, transport, and refreshing. The sensors demonstrated a consistent response and analyte selectivity in vitro and in wound exudate. iCares was designed for rapid scalable manufacturing through advanced printing and laser patterning. Wireless connectivity supported long-term continuous monitoring in wounds. The iCares system real-time monitoring was tested in a murine model of diabetic skin wound during infection and antimicrobial treatment. Clinical wound evaluation was conducted in 20 patients with chronic wounds and in two patients before and after surgery. A machine learning analysis of the multiplexed data successfully classified wounds and healing times, indicating that wound exudate analysis by iCares could offer insight into chronic wound status to aid in treatment decisions.

Bimetallic Metal-Organic Framework Microneedle Array for Wound Healing through Targeted Reactive Oxygen Species Generation and Electron Transfer Disruption

The development of reactive oxygen species (ROS)-based antibacterial strategies that overcome ROS's ultrashort diffusion distance and disrupt bacterial electron transfer represents a promising yet underexplored avenue for nonantibiotic therapies. In this study, we introduce an iron-copper bimetallic metal-organic framework (MOF) with peroxidase (POD)-like enzymatic activity engineered to integrate dual functionalities: bactericidal recognition and electron transfer disruption to synergistically enhance antibacterial efficacy. Mechanistic investigations reveal that boronic-acid-cis-diol interactions enable the MOF to selectively bind to bacterial membranes, where it generates localized ROS, effectively killing bacteria. Concurrently, the alignment of MOF energy levels with the bacterial redox potential facilitates efficient electron transfer from the bacterial membrane to the MOFs, disrupting membrane integrity and inhibiting critical processes such as electron transport and ATP synthesis. When incorporated into biodegradable microneedle patches, the MOF effectively penetrates biofilms and wound exudates, delivering potent antibacterial effects directly to infection sites while simultaneously promoting tissue repair. This strategic combination of bactericidal targeting, electron transfer disruption, and microneedle-mediated delivery highlights the potential of this approach to advance nonantibiotic antibacterial therapies.

A dynamically phase-adaptive regulating hydrogel promotes ultrafast anti-fibrotic wound healing

Achieving rapid and scar-free wound repair is a key goal in the field of regenerative medicine. Herein, a dynamically Schiff base-crosslinked hydrogel (F/R gel) with phase-adaptive regulating functions is constructed to integratedly promote rapid re-epithelization with suppressed scars on chronic infected wounds. Specifically, the gel effectively eliminates multidrug-resistant bacterial biofilm at infection stage via antimicrobial activity of ε-polylysine firstly dissociated from hydrogel matrix in infectious microenvironment, and interrupts the severe oxidative stress-inflammation cycle at wound site by the released ceria nanozyme, thus stimulating a pro-regenerative environment to ensure tissue repair. Subsequently, fibroblast growth factor/c-Jun siRNA co-loaded microcapsules gradually disintegrate to release drugs, facilitating neoangiogenesis and cell proliferation but simultaneously blocking c-Jun overexpression for fibrotic scar suppression. Notably, the F/R gel facilitates normal-like skin regeneration with no perceptible scars formed on infected male mouse wound and female rabbit ear wound models. Our work offers a promising regenerative strategy emphasizing immunomodulatory and fibroblast subtype modulation for scarless wound repair.

Oxygen-generating and antibacterial xanthan gum/PLA aerogels loaded with dexamethasone for potential wound healing

Chronic wounds do not heal within a reasonable time frame due to hypoxia and bacterial inflammation, creating an urgent need for advanced biomaterials to address these challenges. In this study, oxygen-generating, antibacterial xanthan gum-polylactic acid (XA/PLA) aerogels loaded with dexamethasone were developed for the first time for potential wound healing applications. The aerogels contained sodium percarbonate and calcium peroxide as oxygen-releasing agents, providing sustained oxygen release for up to 48 h. The aerogels had a highly porous structure with a high specific surface area (up to 396 ± 8 m2/g) and revealed high liquid absorption capacity in simulated body fluid, absorbing up to 67 times their original weight and remaining stable for 72 h. The in vitro release tests showed controlled profiles of dexamethasone over 24 h. The antibacterial tests demonstrated strong antibacterial activity against Escherichia coli (an up to 15.92 mm inhibition zone diameter) and Staphylococcus aureus (up to a 31.07 mm inhibition zone diameter). The in vitro biocompatibility assays revealed good cytocompatibility with mouse fibroblast cells (NIH/3T3), with a cell viability of >90%. Hemocompatibility tests showed no hemolytic activity with human blood (lysis rate <2%). Overall, these results emphasise the versatility of the XA/PLA aerogels and their potential for the treatment of chronic wounds.

Exudate Management, Facile Detachment, and Immunometabolism Regulation for Wound Healing Using Breathable Dressings

Developing breathable dressings with multifunctional properties (such as exudate management, easy removal, and immunometabolism regulation) presents significant challenges in wound healing. This study employs the Hofmeister effect to prepare a sodium citrate-cross-linked cryogel (CA-CS) with versatile functions, including porous and loose structures, rapid shape recovery ability, superior fatigue resistance behavior, and outstanding biocompatibility capabilities. The CA-CS cryogels demonstrated strong anti-inflammatory properties by reversing the lipopolysaccharides-induced M1 macrophages and increasing M2 macrophage percentages in vitro. Additionally, these breathable CA-CS cryogels exhibited superior hemostatic activity in vivo. The easily detachable CA-CS cryogels enhanced nutrient exchange, promoted exudate absorption, regulated immune response, and induced metabolic reprogramming, thereby supporting skin regeneration and hair follicle formation in a full-thickness skin defect mouse model. We expect that these CA-CS cryogels will drive the development of next-generation dressings for effective wound regeneration in clinical practice.

MicroRNA-122-5p is upregulated in diabetic foot ulcers and decelerates the transition from the inflammatory to the proliferative stage

BACKGROUND

Shifting from the inflammatory to the proliferative phase represents a pivotal step during managing diabetic foot ulcers (DFUs); however, existing medical interventions remain insufficient. MicroRNAs (miRs) highlight notable capacity for accelerating the repair process of DFUs. Previous research has demonstrated which miR-122-5p regulates matrix metalloproteinases under diabetic conditions, thereby influencing extracellular matrix dynamics.

AIM

To investigate the impact of miR-122-5p on the transition from the inflammatory to the proliferative stage in DFU.

METHODS

Analysis for miR-122-5p expression in skin tissues from diabetic ulcer patients and mice was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). A diabetic wound healing model induced by streptozotocin was used, with mice receiving intradermal injections of adeno-associated virus -DJ encoding empty vector or miR-122. Skin tissues were retrieved at 3, 7, and 14 days after injury for gene expression analysis, histology, immunohistochemistry, and network studies. The study explored miR-122-5p's role in macrophage-fibroblast interactions and its effect on transitioning from inflammation to proliferation in DFU healing.

RESULTS

High-throughput sequencing revealed miR-122-5p as crucial for DFU healing. qRT-PCR showed significant upregulation of miR-122-5p within diabetic skin among DFU individuals and mice. Western blot, along with immunohistochemical and enzyme-linked immunosorbent assay, demonstrating the upregulation of inflammatory mediators (hypoxia inducible factor-1α, matrix metalloproteinase 9, tumor necrosis factor-α) and reduced fibrosis markers (fibronectin 1, α-smooth muscle actin) by targeting vascular endothelial growth factor. Fluorescence in situ hybridization indicated its expression localized to epidermal keratinocytes and fibroblasts in diabetic mice. Immunofluorescence revealed enhanced increased presence of M1 macrophages and reduced M2 polarization, highlighting its role in inflammation. MiR-122-5p elevated inflammatory cytokine levels while suppressing fibrotic activity from fibroblasts exposed to macrophage-derived media, highlighting its pivotal role in regulating DFU healing.

CONCLUSION

MiR-122-5p impedes cutaneous healing of diabetic mice via enhancing inflammation and inhibiting fibrosis, offering insights into miR roles in human skin wound repair.

Low-Irradiance Antimicrobial Blue Light-Bathing Therapy for Wound Infection Control

The prevalence of antibiotic resistance and tolerance in wound infection management poses a serious and growing health threat, necessitating the exploration of alternative approaches. Antimicrobial blue light therapy offers an appealing, non-pharmacological solution. However, its practical application has been hindered by the requirement for high irradiance levels (50-200 mW/cm2), which particularly raises safety concerns. Here, a light-bathing strategy is introduced that employs prolonged, continuous exposure to blue light at an irradiance range lower by more than an order of magnitude (5 mW/cm2). This method consistently applies bacteriostatic pressure, keeping wound bioburden low, all while minimizing photothermal risks. Leveraging tailor-made, wearable light-emitting patches, preclinical trials on rat models of wound infection are conducted, demonstrating its safety and efficacy for suppressing infections induced by methicillin-resistant Staphylococcus aureus (S. aureus) and multidrug-resistant Pseudomonas aeruginosa (P. aeruginosa). The results pave a new way for the application of blue light therapy in wound care.

A dual-modified glucomannan polysaccharide selectively sequesters growth factors for skin tissue repair

Artificial dermal matrixes (ADMs) are valuable clinical options for treating large soft tissue defects, but their suboptimal bioactivities compared with the real tissue limit their therapeutic potential. For example, glycosaminoglycan (GAG) polysaccharides in the native skin vitally and differentially regulate endogenous growth factors (GFs) to maintain tissue homeostasis. However, the GAG used in the current ADMs has often lost such delicate regulation. Here, we developed a novel polysaccharide-based ADM that can promote skin tissue repair through selective modulation of specific pro-healing GFs. First, we prepared a plant-derived backbone of glucomannan (named BSP) - representing the two dominant monosaccharide components in the human body - in mass and homogenic quality. Then, we modified this backbone with sulfate and acetyl groups in a controlled manner to yield an optimized BSP derivative (SMAL-BSP) as a main composition to generate a new ADM. In vitro, SMAL-BSP enabled the ADM to selectively sequester pro-angiogenic GFs of VEGF-A and FGF-2 in situ for stimulating endothelial cell growth. Moreover, the addition of the acetyl group induced macrophages to secrete nitric oxide (NO) with antibacterial activities. Further in vivo tests in a rat model of full-thickness skin wounds indicated that SMAL-BSP ADM could sequester GFs in situ to promote angiogenesis and thus tissue regeneration, with superior effects than conventional chondroitin sulfate-based ADM, while showing no adverse effects often associated with animal-derived products. Our study represents a novel strategy for ADM design, targeting selective GF sequestration towards optimal skin tissue regeneration.

Dissolving Microneedles Embedded with Photosensitizers for Targeted Eradication of Gram-Positive Bacteria in Multidrug-Resistant Biofilms in Diabetic Wound Infections

Chronic nonhealing wounds, common in diabetic patients, represent a major clinical challenge, causing significant morbidity and healthcare costs. Persistent bacterial biofilms are a critical obstacle to wound healing, necessitating their effective elimination to promote rapid recovery. In photodynamic antimicrobial therapy (PDAT), enhancing the interaction between the photosensitizer and bacterial biofilms is key to achieving efficient antimicrobial and antibiofilm effects. Here, a novel dissolvable microneedle patch containing a benzoxaborole (BOB)-functionalized photosensitizer is designed, TPI-BOB, for bacteria-specific targeting and localized PDAT of multidrug-resistant biofilm infections in diabetic wounds. TPI-BOB integrates a BOB moiety for selective bacterial binding and a pyridine-based cationic group to enhance electrostatic interactions, showing superior antimicrobial activity in Gram-positive bacteria, particularly MRSA. To further optimize therapeutic delivery and combat biofilm-associated infections, TPI-BOB is incorporated into dissolvable microneedles, which rapidly disintegrate upon application to wound sites. This microneedle system facilitates localized, efficient delivery of TPI-BOB to bacterial biofilms, where it triggers photodynamic action under white-light irradiation. This treatment eradicates the biofilm, initiating tissue repair that reduces inflammation, promotes collagen deposition, and stimulates angiogenesis, accelerating healing. This work presents a novel strategy combining PDAT with microneedle-mediated drug delivery, offering a promising approach for treating diabetic wounds and other biofilm-related infections.

Development of a VEGF-activated scaffold with enhanced angiogenic and neurogenic properties for chronic wound healing applications

Chronic wounds remain in a state of disrupted healing, impeding neurite outgrowth from injured nerves and poor development of new blood vessels by angiogenesis. Current therapeutic approaches primarily focus on the restoration of vascularization and overlook the need of nerve regeneration for complete healing. Vascular endothelial growth factor (VEGF) is a critical growth factor supporting angiogenesis in wound healing, promoting vascularization and has also demonstrated neuro-protective capabilities in both central and peripheral nervous system. While the delivery of pro-regenerative recombinant growth factors has shown promise, gene delivery offers greater stability, reduced off-target side effects, diminished cytotoxicity, and lower production costs. In this context, the overarching goal of this study was to develop a VEGF-activated scaffold with the potential to provide a multifaceted response that enhances both angiogenesis and nerve repair in wound healing through the localized delivery of plasmid encoding VEGF (pVEGF) encapsulated within the GET peptide system. Initially, delivery of pVEGF/GET nanoparticles to dermal fibroblasts led to higher VEGF protein expression without a compromise in cell viability. Transfection of dermal fibroblasts and endothelial cells on the VEGF-activated scaffolds resulted in enhanced VEGF expression, improved endothelial cell migration and organization into vascular-like structures. Finally, the VEGF-activated scaffolds consistently displayed enhanced neurogenic ability through improved neurite outgrowth from neural cells in in vitro and ex vivo models. Taken together, the VEGF-activated scaffold demonstrates multifaceted outcomes through the induction of pro-angiogenic and neurogenic responses from dermal, vascular and neural cells, illustrating the potential of this platform for the healing of chronic wounds.

Skin and Wound Healing: Conventional Dosage versus Nanobased Emulsions Forms

The skin plays a crucial role in the body's homeostasis through its thermoregulation functions, metabolic activity, and, mainly, its barrier function. Once this system has its homeostasis disturbed, through the promotion of tissue discontinuity, an injury happens and a restoration process starts. Different products can be used to promote, accelerate, or stimulate the healing process, such as hydrogels, emulsions, and ointments (main conventional formulations). Despite the historical use and wide market and consumer acceptance, new systems emerged for wound management with the main challenge to overcome conventional form limitations, in which nanosystems are found, mainly nanobased emulsion forms (nano- and microemulsions, NE and ME). Here, we discuss the skin function and wound healing process, highlighting the cellular and molecular processes, the different wound classifications, and factors that affect physiological healing. We also investigated the recent patents (2012-2023) filed at the United States Patent and Trademark Office, where we found few patents for conventional forms (hydrogels = 5; emulsions = 4; ointments = 6) but a larger number of patents for nanobased emulsions filed in this time (NE = 638; ME = 4,072). Furthermore, we address the use of nanobased emulsions (NE and ME) and their particularities, differences, and application in wound treatment. This work also discusses the challenges, bottlenecks, and regulatory framework for nanosystems, industrial, academic, and government interest in nanotechnology, and future perspectives about this key factor for the nanosystems market and consumer acceptance.

lncRNAs GAS5 and MALAT1 Contained in Human Adipose Stem Cell (hASC)-Derived Exosomes Drive the Cell-Free Repair and Regeneration of Wounds In Vivo

Wound healing progresses through four phases: hemostasis, inflammation, proliferation, and remodeling. Wounds may become chronic if this process is disrupted. The use of small extracellular vesicle (sEV; EVs < 200 nm) exosomes (exo; ~40-120 nm) derived from human adipose stem cells (hASCs) as a treatment for wounds is well studied. The cargo of these exosomes is of great interest as this accelerates wound healing. Our previous studies identified lncRNAs GAS5 and MALAT1 as packaged and enriched in hASC exosomes. In this study, we use a rat model to examine the effects on wound healing when hASC exosomes are depleted of GAS5 and MALAT1. Rats were wounded and wounds were treated with 100 μg hASCexo or hASCexo-G-M every 2 days for 1 week. qPCR was completed to evaluate the molecular effects of depletion of GAS5 and MALAT1 from hASCexo. RNAseq was performed on wound tissue to evaluate the molecular mechanisms changed by hASCexo-G-M in wound healing. While hASCexo-G-M significantly improved wound healing rate compared to control wounds, healing occurred slower than in wounds treated with hASCexo that were not depleted of GAS5 and MALAT1. Overall, this study reveals that molecular functions associated with healing are reduced in the absence of GAS5 and MALAT1, highlighting the importance of these lncRNAs.

Molecular-Cellular Two-Pronged Reprogramming of Inflammatory Soft-Tissue Interface with an Immunosuppressive Pure DNA Hydrogel

Effective modulation of persistent inflammation is crucial for chronic wound healing. However, the interaction cascade between inflammatory factors and immune cells at the soft-tissue wound interface poses an incredible challenge for this purpose. Here, we report an immunosuppressive pure DNA hydrogel (Is-pDNAgel) that reprograms inflammatory responses from both molecular and cellular dimensions. Specifically, high-density negative charges enable Is-pDNAgel to efficiently scavenge free chemokines, mitigating neutrophil and macrophage infiltration. Moreover, its immunosuppressive domain synergistically acts on activated residual immune cells and suppresses multiple proinflammatory signaling pathways, thereby creating a positive circuit to boost anti-inflammatory efficacy. Is-pDNAgel can further facilitate migration and proliferation of endogenous endothelial cells owing to its intrinsic extracellular matrix-mimicking structure, promoting re-epithelialization and neovascularization for tissue regeneration without additional bioactive components. Such an "all-in-one" hydrogel outperforms a commercial dressing to accelerate the healing of chronic wounds in a diabetic mouse model, offering a valuable tool for developing regenerative medicine.

Facile Fabrication of Injectable Multifunctional Hydrogels Based on Gallium-Polyphenol Networks with Superior Antibacterial Activity for Promoting Infected Wound Healing

Multifunctional hydrogels hold significant promise for promoting the healing of infected wounds but often fall short in inhibiting antibiotic-resistant pathogens, and their clinical translation is limited by complex preparation processes and high costs. In this study, a multifunctional hydrogel is developed by combining metal-phenolic networks (MPNs) formed by tannic acid (TA) and gallium ions (Ga3⁺) with chitosan (CS) through a simple one-step method. The resulting CS-TA-Ga3⁺ (CTG) hydrogel is cost-effective and exhibits desirable properties, including injectability, self-healing, pH responsiveness, hemostasis, antioxidant, anti-inflammatory, and antibacterial activities. Importantly, the CTG hydrogels are effective against antibiotic-resistant pathogens due to the unique antibacterial mechanism of Ga3⁺. In vivo studies demonstrate that the CTG hydrogel promotes follicle formation and collagen deposition, accelerating the healing of infected wounds by inhibiting blood loss, suppressing bacterial growth, and modulating the inflammatory microenvironment. These findings highlight the CTG hydrogel's potential as an advanced and translational dressing for enhancing the healing of infected wounds.

Chitosan membranes incorporating Aloe vera glycolic extract with joint synthesis of silver nanoparticles for the treatment of skin lesions

New wound dressings based on polymeric membranes have been widely exploited for clinical applications to assist in the healing process and prevent additional complications (e.g., bacterial infections). Here we propose the development of a new production method of polymeric membranes based on chitosan, incorporating glycolic extract of Aloe vera with joint synthesis of silver nanoparticles for use as a new bioactive dressing. The membranes were obtained by casting technique, and their morphological, physicochemical characteristics, degree of swelling, degradation profile and antimicrobial activity evaluated. Morphological analyzes confirmed the synthesis and presence of silver nanoparticles in the polymeric membrane. The chemical compatibility between the materials was demonstrated through thermal analysis (TGA and DSC) combined with ATR-FTIR tests, showing the complexation of the membranes (Mb-Ch-Ex.Av-NPs). All membranes were characterized as hydrophilic material (with a contact angle (ө) < 90°); however, the highest degree of swelling was obtained for the chitosan. (Mb-Ch) membrane (69.91 ± 5.75%) and the lowest for Mb-Ch-Ex.Av-NPs (26.62 ± 8.93%). On the other hand, the degradation profile was higher for Mb-Ch-Ex.Av-NPs (77.85 ± 7.51%) and lower for Mb-Ch (57.60 ± 2.29%). The manufactured bioactive dressings showed activity against Escherichia coli and Staphylococcus aureus. Our work confirmed the development of translucent and flexible chitosan-based membranes, incorporating Aloe vera glycolic extract with joint synthesis of silver nanoparticles for use as a new bioactive dressing, with proven antimicrobial activity.

MicroRNA Expression in Chronic Venous Leg Ulcers and Implications for Wound Healing: A Scoping Review

Purpose: Chronic venous leg ulcers (CVLUs) comprise the majority of lower-extremity wounds, yet their pathophysiology is not fully understood. While research has shown that microRNAs are an important component of wound inflammation, few have explored the role of microRNAs (miRNAs) in the healing of CVLUs. This scoping review examines miRNAs in CVLUs and the association with wound healing. Methods: In December 2023, we searched MEDLINE/PubMed, Embase, Scopus, and CINAHL for studies published in 2013-2023 examining miRNAs in CVLU healing. Results: Six studies met inclusion criteria. MicroRNAs were extracted from various specimens including serum, skin biopsy samples, and adipose tissue-derived mesenchymal cells from individuals with CVLUs. Overexpression of miR-221, miR-222, miR-92a, and miR-301a-3p hindered angiogenesis, while overexpression of miR-296, miR-126, miR-378, and miR-210 facilitated angiogenesis. Overexpression of miR-34a/c, miR-301a-3p, miR-450-5p, miR-424-5p, miR-516-5p, and miR-7704 increased local inflammatory responses and inhibited keratinocytes proliferation, impairing healing, while overexpression of miR-19a/b and miR-20 downregulated keratinocytes' inflammatory response, promoting healing. Downregulation of miR-205, miR-96-5p, and miR-218-5p enhanced cellular proliferation and promoted wound healing. Downregulation of miR-17-92 was linked with impaired healing. Discussion: MicroRNAs play a role in regulating angiogenesis, inflammatory responses, and cell migration in chronic-wound healing. However, studies of miRNAs in CVLUs are limited and lack a standardized approach to measurement and quantification. Further research is warranted to elucidate the mechanisms underlying microRNA involvement in CVLU healing to better understand the pathophysiology and for the future development of targeted therapies.

Recent advances in nanomaterials and their mechanisms for infected wounds management

Wounds infected by bacteria pose a considerable challenge in the field of healthcare, particularly with the increasing prevalence of antibiotic-resistant pathogens. Traditional antibiotics often fail to achieve effective results due to limited penetration, resistance development, and inadequate local concentration at wound sites. These limitations necessitate the exploration of alternative strategies that can overcome the drawbacks of conventional therapies. Nanomaterials have emerged as a promising solution for tackling bacterial infections and facilitating wound healing, thanks to their distinct physicochemical characteristics and multifunctional capabilities. This review highlights the latest developments in nanomaterials that demonstrated enhanced antibacterial efficacy and improved wound healing outcomes. The antibacterial mechanisms of nanomaterials are varied, including ion release, chemodynamic therapy, photothermal/photodynamic therapy, electrostatic interactions, and delivery of antibacterial drugs, which not only combat bacterial infections but also address the challenges posed by biofilms and antibiotic resistance. Furthermore, these nanomaterials create an optimal environment for tissue regeneration, promoting faster wound closure. By leveraging the unique attributes of nanomaterials, there is a significant opportunity to revolutionize the management of infected wounds and markedly improve patient outcomes.

Collagen-based hydrogel derived from amniotic membrane loaded with quercetin accelerates wound healing by improving stereological parameters and reducing inflammation in a diabetic rat model

In clinical practice, there is a demand for innovative wound healing methods to tackle full thickness skin injuries, especially in those with diabetes. In this study, we examined if collagen-based hydrogel from amniotic membrane (CHAM) loaded with quercetin could enhance healing in diabetic rats. Sixty diabetic rats were randomly divided into the control group, CHAM group, quercetin group, and CHAM+Quercetin group. Sampling took place on days 4 and 8 for additional evaluations. Our findings showed that the rates of wound contraction, volumes of new epidermis and dermis, fibroblast and blood vessel counts, collagen deposition, and concentrations of TGF-β1 and VEGF cytokines were significantly higher in the treatment groups compared to the control group, with these changes being more pronounced in the CHAM+Quercetin group. This is while the counts of neutrophils and macrophages, along with the concentration levels of IL-6, IL-1β, and TNF-α cytokines dropped more noticeably in the CHAM+Quercetin group in comparison to the other groups. In summary, it was determined that the combination of CHAM and quercetin significantly enhances diabetic wound healing.

Comparative Study between Platelet-rich Plasma, Platelet-derived Growth Factor Gel, and Normal Saline Dressing in Chronic Ulcer Healing

BACKGROUND

Chronic ulcers pose significant challenges in clinical management due to their prolonged healing time and high recurrence rates. Various treatment modalities have been explored to enhance the healing process. Among these, platelet-rich plasma (PRP) and platelet-derived growth factor (PDGF) gel have shown promising results due to their regenerative properties. This study aims to compare the efficacy of PRP, PDGF gel, and normal saline dressing in the healing of chronic ulcers, focusing on wound shrinkage, healing duration, and complication rates.

AIM

The aim of the study was to study and compare the efficacy of PRP, PDGF dressings, and normal saline dressings in chronic nonhealing ulcers.

MATERIALS AND METHODS

The study was conducted in general surgery department, tertiary hospital. This is a prospective, observational study involving patients with chronic nonhealing ulcers. A total of 105 patients were enrolled in the study, with 35 patients allocated to each treatment group. Participants were evaluated at baseline and followed up weekly for 8 weeks. The primary outcome measures included wound size reduction, time to complete healing, and the incidence of any complications or adverse effects. The secondary outcomes included patient-reported pain levels and quality-of-life assessments.

RESULTS

The demographic data and baseline characteristics were comparable across the three groups. The mean age of participants was 56.2 years, with a slight male predominance (58%). The PRP group demonstrated the highest mean wound size reduction of 75% by the end of the study period, followed by the PDGF gel group with 68%, and the normal saline group with 45%. The differences between the groups were statistically significant ( P < 0.05). The average time to complete healing was 5.2 weeks for the PRP group, 6.1 weeks for the PDGF gel group, and 7.8 weeks for the normal saline group. The PRP group showed significantly faster healing compared to the other groups ( P < 0.05). Complication rates were low across all groups, with minor adverse effects reported. The PRP group had a 5% incidence of mild local infection, while the PDGF gel group had a 7% incidence. No serious adverse effects were observed. Patient-reported pain levels decreased significantly in all groups, with the most substantial reduction observed in the PRP group. Quality of life improvements were also most pronounced in the PRP group, followed by the PDGF gel group and the normal saline group.

CONCLUSION

This study concludes that PRP is a highly effective treatment for chronic ulcers, offering faster wound healing and greater wound size reduction compared to PDGF gel and normal saline dressing. PDGF gel also presents a viable alternative with good efficacy. Normal saline, while less effective, remains a baseline treatment option. Further research with larger sample sizes and longer follow-up periods is recommended to confirm these findings and optimize treatment protocols. The superior outcomes observed with PRP highlight its potential as a first-line therapy in the management of chronic ulcers, potentially improving patient outcomes and reducing healthcare costs associated with prolonged wound care.

Near-infrared light-responsive nanocomposite hydrogels loaded with epidermal growth factor for diabetic wound healing

In diabetic wounds, the presence of hyperglycemia is often accompanied by a persistent inflammatory response, oxidative stress damage, impaired angiogenesis and bacterial infections around the wound, resulting in impaired proliferation of dermal and epidermal cells and impaired skin regeneration in diabetic wounds. To solve the above problems, this study designed a near-infrared (NIR) light-responsive multifunctional poloxamer hydrogel (EGF/PDA-MXene Gel). The Gel is composed of two-dimensional nanomaterials (2D NMs) MXene as the core, modified by polymer, further loaded with epidermal growth factor (EGF), and has antibacterial, antioxidant, photothermal properties. Meanwhile, EGF/PDA-MXene Gel can be used as a drug repository, alleviating the problem of short half-life, and realizing the sustained release of EGF. The NIR photothermal property induces protein denaturation leading to the death of pathogenic bacteria, avoiding the common clinical problem of antibiotic resistance. In addition, EGF/PDA-MXene Gel promotes diabetic chronic wound healing by promoting epidermal regeneration, collagen deposition, angiogenesis, and several other mechanisms. Therefore, the Gel preparation strategies that combine bioactive molecules with 2D NMs, which maintains the activity of EGF while exploiting the antimicrobial advantages of 2D NMs photothermally, provide a new and promising therapeutic approach for accelerating the repair of chronic infected wounds.

A one-two punch of inflammation and oxidative stress promotes revascularization for diabetic foot ulcers

Patients with diabetic foot ulcers (DFU) suffering from severe lower limb ischemia face the risk of amputation. Concomitant oxidative stress and hyperinflammation commonly manifest within the tissue affected by DFU, exacerbating the deterioration of DFU wounds. One-two punch strategy of anti-oxidative damage plus anti-inflammatory is anticipated to tackle the challenge of non-healing diabetic wounds. Here, we introduced a dual-approach treatment strategy involving the probiotic Weissella cibaria (WC) modified with desferrioxamine (DFO). This engineered probiotic, known as WC@DPA, aims to ameliorate oxidative stress within the ischemic microenvironment and stimulate the formation and proliferation of endothelial tubular structures. When applied with chronic wounds and ischemic hindlimb injuries in diabetic mice, WC@DPA gel demonstrated an effective performance in modulating oxidative damage, reducing local vascular inflammation, and facilitating muscle tissue repair and vascular reconstruction. We believe that our engineered probiotic represents a promising therapeutic avenue for managing ischemic injuries associated with DFU.

Functional hydrogels promote chronic infectious wound healing by re-rousing macrophage M1 and inducing bacterial copper-like death

Traditional antibiotics are often ineffective against biofilm-associated infections, and biofilm-induced macrophage immune evasion directly halts the wound healing process. Disrupting biofilms and regulating macrophage immune functions are critical to improving wound healing. In this study, we synthesized g-C3N4 with peroxidase (POD) enzyme activity via thermal polymerization and copper alginate microspheres (CAM) via gas cutting. These were co-encapsulated into GelMA hydrogels to form a functionalized wound repair system (GelMA/CAM@g-C3N4) with both anti-biofilm and local immune microenvironment remodeling capabilities. In vitro, this system exhibited excellent biocompatibility and promoted endothelial cell migration, vascular formation, and CD31 expression. It also polarized macrophages toward the M1 phenotype, restoring their pro-inflammatory functions, upregulating inflammatory cytokines (IL-1, IL-6, TNF-α), and inhibiting Staphylococcus aureus and Escherichia coli. In vivo, the system suppressed S. aureus growth, promoted angiogenesis and collagen deposition, and reshaped the pathological microenvironment to achieve wound repair and regeneration. Conclusions: This system offers a new therapeutic strategy for chronic infectious wounds.

Nanoconfinement-guided in situ co-deposition of single-atom cascade nanozymes combined with injectable sodium alginate hydrogels for enhanced diabetic wound healing

Treating diabetic wounds remains a major clinical challenge due to high glucose levels, bacterial infection, insufficient oxygen supply, and oxidative stress. Herein, guided by the nanoconfinement effect, single-atom Au/Pt nanoparticles (NPs) are in situ co-deposited in mesoporous metal-organic frameworks (MOF), while synergizing with DNA aptamer (DNA-Apt) with bacterial targeting functionality and an excellent biocompatible sodium alginate hydrogel (Gel), to prepare a multifunctional bimetallic cascade nanozyme combine hydrogels (Au-Pt@ZIF-8/Apt@gel). ZIF-8 degrades in the acidic environment of a wound infection, releasing Zn2+ and Au/Pt nanoparticles, which produce reactive oxygen species (ROS) under the catalysis of glucose to inactivate bacteria. Notably, Au-Pt@ZIF-8 nanozymes depositing Au/Pt nanoparticles exhibit a nanoconfinement effect that enhances the cascade nanozymes activity, which is about 2-3 times higher than that of monoconfined or nonconfined nanozyme. In addition, in vitro bacteriostatic tests show the nanozymes have broad-spectrum antimicrobial effects, with better inhibition of Gram-positive than negative bacteria. In vivo experiments indicate that Au-Pt@ZIF-8/Apt@gel has satisfactory antibacterial efficacy in both normal and diabetic mice, as well as optimal skin wound healing ability and significant reduction of inflammation in infected wounds. Consequently, the proposed system holds great potential for developing integrated nanoplatforms for on-demand treatment of bacterial-infected diabetic wounds.

Electrochemical pH Sensor Incorporated Wearables for State-of-the-Art Wound Care

Nonhealing chronic wounds pose severe physiological and psychological distress to patients, making them a significant concern for global public health. Effective wound management strategies assisted by smart wearable pH monitoring have the potential to substantially alleviate both social and economic burdens. The pH of the wound exudate serves as a valuable indicator for predicting infections and assessing the healing status of wounds. This review comprehensively summarizes fundamental aspects related to wound pH, with a particular emphasis on the relationships between pH and healing status, infections, and other biochemical parameters that are crucial for wound health. It systematically discusses advancements in electrochemical pH sensors specifically designed for wearable devices, emphasizing their core performance in the care of chronic wounds. Additionally, the review outlines the challenges faced by this field and suggests future directions for research and development.

Maresin-1 impairs cutaneous wound healing response

Maresin-1 is a derivative of docosahexaenoic acid with strong anti-inflammatory action in various disease models. However, these effects may not always be beneficial. In instances like cutaneous diseases in which wound healing is important, inflammation is required. In this study, we investigated the effects of maresin-1 on cutaneous wound healing and found that wound healing was significantly delayed in maresin-1-treated mouse skin in the early phase of wound healing on days 1 to 3. Histological analyses revealed that maresin-1 suppressed re-epithelization in the wounded skin. Despite the direct influence of maresin-1 on keratinocyte migration, a comprehensive quantitative polymerase chain reaction analysis revealed that maresin-1-treated wound skin showed a decrease in tumor necrosis factor α, indicating that maresin-1 indirectly suppresses keratinocyte migration mediated by reduced tumor necrosis factor α derived from wounded skin, leading to delayed wound healing.