Diabetic Wound Healing Research Articles

Diabetic wounds remain a formidable clinical challenge due to their delayed healing, frequent infections, and high recurrence rates. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, may hinder diabetic wound repair through multifaceted mechanisms. This review elucidates the regulatory pathways of ferroptosis, focusing on its disruptive effects on critical reparative cells (macrophages, fibroblasts, endothelial cells, and keratinocytes) and bacterial infections in the wound microenvironment. We further systematically evaluate the therapeutic potential of ferroptosis-targeting agents in promoting diabetic wound healing, thereby providing a theoretical framework for developing precision interventions against ferroptosis.

Diabetic wound healing remains a major challenge, as persistent bacterial infections and chronic inflammation can delay healing and lead to scar formation. Herein, a novel self-powered microneedle patch (SPMNP), combined with mild microwave thermal (MT) therapy, is developed to promote the scarless healing of infected diabetic wounds. The SPMNP is fabricated by integrating a piezoelectric nanogenerator (PENG) with a microneedle patch (CFeZ/MNP) loaded with Curcumin@Fe3O4-COOH@ZIF-8 nanoparticles (CFeZ NPs). The CFeZ NPs endow the CFeZ/MNP with a mild MT effect under microwave irradiation, enabling elimination of bacteria and biofilms. Owing to the boronic ester bonds and MT effect, CFeZ/MNP facilitates responsive release of curcumin under both the infected diabetic wound microenvironment and microwave irradiation. The PENG collects and converts biomechanical motion to electrical stimulation to further promote wound healing. In vitro experiments demonstrate that SPMNP synergizes with mild MT therapy to promote M2 macrophage polarization as well as enhance cell proliferation and migration. In a Staphylococcus aureus-infected diabetic wound model, the SPMNP combined with mild MT therapy can eliminate bacteria, inhibit inflammatory response and pro-fibrotic cytokines expression, promote tissue regeneration, and ultimately promote scarless healing of infected diabetic wound. This study provides a promising therapeutic strategy for the scarless healing of infected diabetic wounds.

Diabetic wounds suffer from delayed healing due to impaired angiogenesis, bacterial infection, and mechanical damage from dressing changes. This study developed an AP-G-OSA-GB-ICG hydrogel via Schiff base and borate ester bonds. The temperature-responsive conductive system integrates photothermal therapy (PTT) and nitric oxide (NO) release for synergistic antibacterial effects. Graphene oxide-BNN6 (GB) and indocyanine green (ICG) eliminate bacteria via near-infrared (NIR) photothermal effects, while light-triggered NO from BNN6 promotes angiogenesis. Gelatin-based thermal responsiveness enables body temperature-triggered adhesion switching to reduce neotissue damage. Graphene oxide (GO) endows electrical conductivity for potential physiological signal monitoring. In type 1 diabetic SD rats, the hydrogel with NIR irradiation and NO release achieved 100% wound closure at day 14. Masson trichrome staining showed orderly collagen fiber deposition, CD31 and α-SMA immunostaining confirmed a significant increase in vessel density. Hematoxylin and eosin (H&E) staining further revealed the absence of significant inflammatory cell infiltration. This multifunctional system integrates antibacterial activity, angiogenesis promotion, intelligent adhesion, and physiological monitoring, offering a mechanistically innovative and clinically translatable strategy for diabetic wound precision treatment.

Background: While macrophage to myofibroblast transition (MMT) has been reported in various tissues and diseases, it has not been studied in wound healing. We sought to identify the epigenetic mechanisms that control MMT during wound repair and if MMT is epigenetically altered in diabetic wound healing. Methods: We used a combination of transgenic murine models, loss of function approaches in vitro and in vivo , pharmacologic inhibition in vivo , flow cytometry, spatial sequencing, and single cell RNA sequencing (scRNA-seq) in human and murine wounds. Results: Flow cytometry of whole wounds from Col1a1-GFP reporter mice identified a CD3 - CD19 - Ly6G - CD11b + F4/80 + resident macrophage population undergoing MMT from day 5 to 7 post-wounding (p<0.05). We identified the H3K36 methyltransferase Whsc1 was upregulated in wound macrophages in response to TGFβ, and siRNA knockdown of Whsc1 in bone marrow derived macrophages (BMDMs) decreased expression of Acta2, Col1a1, Col3a1 and H3K36me2 at fibrotic promoters (p<0.05). Myeloid-specific Whsc1 loss in Whsc1f lox/flox ;Lyz2 Cre+ mice impaired wound healing and decreased Acta2 , Col1a1 , and Col3a1 expression in wound macrophages. Local pharmacologic inhibition of Whsc1 in vivo disrupted wound healing (p<0.05). Flow cytometry of wounds isolated from Col1a1-GFP mice revealed fewer resident macrophages from mice on a diabetic diet (DIO) (2%) versus normal diet (15%) (p<0.05). Spatial sequencing of human wounds identified resident macrophages (F CGR1A, ITGAM, MERTK, CCR2, SIGLEC1, CX3CR1, CD163, LYVE1, MRC1, TIMD4, and CD9 positive) represented 4.4% of total macrophages ( CD14, CD16 , and CD68 positive ), exhibited increased TGFB1 expression compared to non-resident macrophages, and were in closer proximity to fibroblast neighbors. scRNA-seq of human wounds revealed that Whsc1 expression was decreased in macrophages from diabetic wounds (p<0.05). In DIO BMDMs, Whsc1 was absent at fibrotic promoters after TGFβ treatment and remained at NFkB-regulated inflammatory gene promoters ( Il1b, Il6, Tnf ) bound to RelA. RelA knockdown in DIO BMDMs increased Whsc1 at fibrotic promoters and lead to increased fibrotic gene expression (p<0.05). Conclusion: We show that MMT occurs in the resident macrophage subpopulation during wound healing and is regulated by TGFβ-Whsc1, which is disrupted in diabetic wound healing. These data identify the RelA-Whsc1 interaction as a novel target in diabetic wound treatment.

Impaired wound healing in aged and diabetic wounds involves complex cellular dysregulation that hinders tissue repair. Using single-cell RNA sequencing (scRNA-seq) and validation techniques, we investigated impaired wound healing to identify whether there were significant changes linked to each condition. Comparative mucosal wound analysis revealed distinct differences between diabetic and normoglycemic (NG)-aged mice, which had an impact on connective tissue formation and epithelial closure. Wounds in NG-aged mice exhibited prolonged granulation tissue and upregulation of genes linked to chemotaxis, cell migration, neutrophil degranulation, and antimicrobial defense pathways compared to the diabetic wounds. In comparison to healing in young animals, wounds in NG-aged mice had a shift in fibroblast subtypes with fewer matrix-producing myofibroblasts and increased inflammatory fibroblasts. Furthermore, wounds in NG-aged mice versus wounds in diabetic mice had an upregulation of lytic enzymes, with striking differences in cathepsin-expressing fibroblasts. Since diabetic wounds healed more slowly than wounds in NG-aged mice, the results suggest that the upregulation of lytic enzymes that characterized diabetic wounds is particularly damaging to healing. In addition to the transcriptional differences, pseudotime analysis revealed that fibroblasts in wounds from diabetic mice progressed towards a protease-enriched state, while those in aged mice shifted towards an inflammatory phenotype. This is the first study to directly compare aged and diabetic healing at the single-cell level and provides distinct molecular mechanisms that may allow more precise therapeutic targets to improve healing in aged and diabetic wounds.

Introduction: Endothelial cell dysfunction causes recruitment of inflammatory cells to the intima, initiating atheromatous plaque build-up. Atherosclerosis underlies myocardial infarction and stroke which remain leading causes of death in the US. Identifying key regulators that limit endothelial dysfunction is critical. We uncovered a previously unrecognized role of an endocytic adaptor protein, Disabled homolog 2 (Dab2), which regulates endocytosis and lysosomal degradation of receptor tyrosine kinases such as VEGFR2. We found that endothelial Dab2 promoted VEGF signaling during angiogenesis in diabetic wound healing. However, the mechanism how Dab2 in the endothelial cells protected endothelium function in atherosclerosis is unknown. Hypothesis: Endothelial Dab2 protects endothelial function under atherogenic conditions by promoting pulsatile shear (PS)-induced PI3K-Akt-eNOS signaling via endosomal trafficking. PS increases transcription factor KLF4 expression which activates Dab2 expression. Restoring Dab2 in the endothelium offers a therapeutic strategy to limit plaque progression. Methods and Results: We found reduced endothelial Dab2 expression in human atherosclerosis and ApoE-/- mice. We generated endothelial-specific inducible Dab2 knockout mice (EC-Dab2iKO) and crossed to ApoE-null background (EC-Dab2iKO/ApoE -/- ). Western diet-fed EC-Dab2iKO/ApoE -/- mice exhibited heightened arterial inflammation, more severe plaque formation, increased macrophage infiltration and reduced plaque stability. Single-cell RNA-seq, qPCR and western blot revealed that endothelial Dab2 depletion significantly upregulated pro-inflammatory markers and shear stress-related atherosclerotic pathways, indicating Dab2 protect against endothelial dysfunction by increasing PS-dependent eNOS activation via endosomal PI3K-Akt activation. ATAC-seq and ChIP-qPCR showed that KLF4 binds to Dab2 promoter. Using an in vitro PS flow channel to mimic atheroprotective flow, we found both Dab2 and KLF4 were increased. Using an endothelial-targeted engineered nanoparticle, we delivered Dab2 mRNA to the atherogenic endothelium to restore Dab2 function. It increased Dab2 level in the atheroma which restrains plaque progression in ApoE-/- mice. Conclusions: Our study reveals Dab2 as a key protector of atherogenic endothelium, linking PS and endothelial homeostasis via KLF4 and PI3K-Akt-eNOS signaling. Targeted restoration of Dab2 may represent a promising therapeutic approach for atherosclerosis.

Abstract Bioelectric fields play a critical role in skin wound repair by guiding cell proliferation, migration, and differentiation, and thereby accelerating wound healing. However, the biochemical microenvironment in diabetic wounds can diminish the endogenous electric fields (EEFs) and severely delay the healing process. Therefore, constructing bionic skin capable of restoring the EEF is an effective strategy for diabetic wound repair. In this study, a thermoelectric hydrogel‐based bionic skin is developed using an artemisinin (ART)‐loaded silver selenide methacrylate hydrogel (Ag 2 Se@GelMA/ART). Using the thermoelectric effect, the bionic skin can generate a bioelectric field driven by a skin‐to‐air temperature gradient, thereby offering a novel approach for restoring EEFs. In vitro studies show that Ag 2 Se@GelMA/ART bionic skin significantly promoted the proliferation, migration, and angiogenesis of human umbilical vein endothelial cells. In vivo, the bionic skin accelerated diabetic wound healing and enhanced neovascularization and collagen deposition. Subsequent observation suggested that the bionic thermoelectric skin generating the external electric field inhibits the expression of prolyl hydroxylase domain‐containing protein 2 (PHD2), and upregulates the hypoxia inducible factor (HIF)‐1α and vascular endothelial growth factor (VEGF)‐A, which can benefit the process of angiogenesis. Thermoelectric bionic skin represents a novel therapeutic strategy for diabetic wound care, offering new avenues for tissue engineering.

Objective: Hypoxia-inducible factor 1 (HIF-1) signaling mediates multiple links of wound healing. Tissue hypoxia and dysregulation of HIF-1 signal play a crucial role in non-healing diabetic wounds. Previous studies have found that roxadustat (FG-4592) can promote epidermal stem cell proliferation by upregulating the HIF signaling pathway. This study aimed to investigate the role of roxadustat in the wound healing of diabetic mice. Material and Methods: The study was divided into in vivo and in vitro experiments. In the in vivo experiment, mice were categorized into three groups: control group, diabetes group, and diabetes + roxadustat group. Diabetic mice were injected intraperitoneally with roxadustat daily at a dose of 10 mg/kg. Hematoxylin & eosin staining and Masson staining were employed to assess wound healing speed and quality. Immunohistochemical staining was used to detect HIF-1a and proliferating cell nuclear antigens. Western blot was conducted to examine markers associated with Notch1 signaling pathway activation (Notch Intracellular Domain [NICD]), keratinocyte differentiation, and angiogenesis. In the in vitro experiment, HaCaT cells were divided into control (Glu 5.5 mM), high-glucose (Glu 30 mM), and high-glucose + drug (Glu 30 mM + FG-4592) groups, with a treatment concentration of FG-4592 set at 10 µM. Following 48 h of treatment period, protein was extracted for co-immunoprecipitation analysis to determine the interaction between HIF-1a and NICD, and fluorescence staining was conducted to assess their co-localization. Results: Roxadustat reversed the slow wound healing caused by diabetes and significantly improved the quality of healing ( P < 0.05). It upregulated the inhibited HIF-1 signaling in diabetic mice ( P < 0.05) and triggered cell proliferation. It downregulated the hyperactivated Notch1 signaling in diabetic mice ( P < 0.05) and induced keratinocyte dedifferentiation, which were both responsible for wound re-epithelialization. Roxadustat also reversed the downregulated expression of vascular endothelial growth factor and CD31 in diabetic mice ( P < 0.05) and accelerated the wound angiogenesis process. Conclusion: Roxadustat shows potential as a therapeutic drug by promoting re-epithelialization and angiogenesis to bring vigor to the impaired diabetic wound.

Diabetic foot ulcers are a severe diabetic complication causing poor healing. Itaconate, a tricarboxylicacid cycle byproduct, has been shown to improve wound healing. This study investigated the potential of 4-octyl itaconate (4-OI), an esterified derivative of itaconate, to modulate efferocytosis andmacrophage pro-resolving function to promote diabetic wound healing. A diabetic mouse wound model was used. For in vitro analysis, RAW264.7 macrophages and apoptotic Jurkat cells were cocultured under high glucose (HG, 30 mM). To further evaluate the roles of macrophages, monocarboxylate transporter 1 (MCT1), and lactate in 4-OI-promoted diabetic wound healing, we used clodronate-liposomes (CLD-Lipo) to deplete macrophages, AZD3965 (an MCT1 inhibitors), telmisartan to validate our hypothesis. In diabetic mice, impaired apoptotic neutrophils clearance and persistent M1 activation delayed wound healing. 4-OI improved diabetic wound repair by enhancing efferocytosis, shifting macrophages toward M2 pro-resolving phenotype, and boosting angiogenesis. 4-OI showed a protective effect mediated by macrophages, while endothelial cells and neutrophils also played synergistic roles in diabetic wound healing. Moreover, 4-OI upregulated MCT1 which, in turn, increased release of lactate triggered by efferocytosis at the wound site. Lastly, we confirmed that pro-resolving effects of 4-OI onmacrophage function were mediated by promoting pro-resolving macrophage proliferation and polarization via efferocytosis-induced lactate release and subsequent activation of G protein-coupled receptor 132 (GPR132). 4-OI promotes diabetic wound healing through macrophage-dependent/independent mechanisms. Moreover, the protective effect of 4-OI on macrophage was mediated through MCT1-mediated lactate release triggered by efferocytosis and subsequent GRP132 activation.

BackgroundDiabetic foot ulcer (DFU) is a severe complication of diabetes mellitus (DM). The present study aimed to explore the role of miR-191-5p and its target VEGFA in the DFU.Methods207 Volunteers were recruited including 105 uncomplicated DM patients and 102 DFU patients. The expression of miR-191-5p and VEGFA were quantified by qRT-PCR. VEGFA protein level was assayed by Western blot. Pearson correlation, ROC curve, and logistic regression evaluated the clinical relevance, diagnostic potential, and risk factors, respectively. High-glucose stimulated Human umbilical vein endothelial cells (HUVEC). Proliferation and migration capability were assayed by CCK-8 and Transwell in HUVEC. The target relationship was assessed by dual-luciferase reporter assay.ResultsmiR-191-5p was enhanced in serum and HG-induced HUVEC and identified as an independent risk factor. miR-191-5p abundance was positively associated with the DFU area, CRP, WBC, and NEUT. Downregulation of miR-191-5p inhibited the HUVEC migration and proliferation potential and mRNA expression of PDGF-, PDGFR-β, and FGF-2. VEGFA was predicted and verified as a target of miR-191-5p. VEGFA abundance was negatively related to miR-191-5p. miR-191-5p impeded HUVEC migration, proliferation, and angiogenesis by regulating VEGFA.ConclusionIn summary, miR-191-5p was related to DFU progression and promoted DFR development. As a potential biomarker, miR-191-5p impeded HUVEC migration, proliferation, and angiogenesis by regulating the target VEGFA.

IntroductionWound of diabetic foot ulcers (DFU) is chronic and hard to heal, characterized by impaired inflammatory response, dysfunction of keratinocyte and endothelial cells and improper removal of dying cells. Efferocytosis, as a trigger for phenotype switch of macrophages, plays a critical role in diabetic foot wound healing. Here, we showed the effect of efferocytosis in wound healing of diabetics and identified seven in absentia homolog 2 (SIAH2) as a potential efferocytosis-related biomarker.MethodsBlood and skin samples were collected from 20 patients diagnosed type II diabetes at Qilu Hospital of Shandong University. Efferocytosis related genes in DFU were identified based on GSE147890, GSE80178 datasets as well as RNA-seq data of blood samples. Enrichment analysis, clustering analysis and protein-protein interaction network analysis were conducted based on the efferocytosis related genes in DFU. An array diagram was constructed and survival analysis of DFU was performed based on the associated clinical data. Single-cell sequencing data analysis combined with experiments in vitro, we analyzed the role of SIAH2 in wound healing of DFU as well as its correlation with efferocytosis signal.ResultsOverall efferocytosis and SIAH2 expression level were increased in DFU blood and tissue samples and associated with poor survival in patients. Single-cell analysis revealed elevated SIAH2 expression is positively associated with keratinocyte migration, angiogenesis and efferocytosis of macrophage in wound healing of DFU. SIAH2 involved in efferocytosis-related cell-to-cell communication, especially in “internalization” and “digestion” signals.ConclusionSIAH2 was identified to be one of the key efferocytosis genes and associated with poor prognosis of DFU. Protective upregulation of SIAH2 was involved in angiogenesis, keratinocyte migration and cell-to-cell communication mediated by efferocytosis in DFU wound healing.

Electrical stimulation (ES) via rigid electrodes near the wound is a promising approach for treating chronic wounds, but it cannot stimulate the entire wound area or address infected wounds. Conductive hydrogels enable both endogenous and exogenous current conduction, promote intercellular signaling, and conduct current from external ES to the wound site, thereby enhancing cell migration and angiogenesis. The combined hydrogel dressing/ES treatment strategy can promote wound healing throughout the entire healing process. Despite significant achievements in accelerating wound healing as electroactive dressings, conductive hydrogels face multiple challenges: an imbalance between high conductivity and mechanical properties, lack of antimicrobial activity, and poor adhesion. This study designed and assembled a CuNP-functionalized bacterial cellulose hydrogel exhibiting outstanding antimicrobial properties and favorable mechanical performance. This hydrogel exhibits conductivity comparable to human skin (41.25 ms/m) and mechanical strength (1120% tensile strain), while maintaining good tissue adhesion (up to 27.34 kPa on pig skin) and antibacterial efficacy (>99%). When combined with exogenous ES on diabetic wounds, the hydrogel promotes collagen deposition and angiogenesis, accelerating skin tissue remodeling (reducing wound area to 24.3% within 7 days). Additionally, it functions as a sensor for monitoring human motion and microexpressions. This conductive hydrogel demonstrates significant potential in chronic wound healing and bioelectronics.

Excessive exudate in chronic wounds increases the risk associated with tissue hydration, bacterial infection, and increased inflammation. While Janus dressings enable unidirectional exudate transport, current designs overlook the critical need for maintaining optimal wound humidity and providing on-demand antibacterial/anti-inflammatory treatment to support repair. To address this, a self-pumping trilayered dressing (GCSIP) is developed, integrating polyhexamethylene guanidine-grafted triglycidyl glycerol ether (PHMG-GTE)-modified cotton, ibuprofen-loaded silk fibroin (IBU/SF), and polyurethane (PU). This architecture achieves autonomous, unidirectional fluid transport and drug release via a controlled reflux mechanism triggered upon full saturation of the cotton layer. A precisely engineered microporous array (400 µm pores, 6mm spacing) is used to optimize directional transport and reflux efficiency. Upon saturation, partial reflux through the array facilitates the release of dissolved SF molecules and 87.6% of the encapsulated ibuprofen (IBU) within 72h. The released components significantly reduced TNF-α and IL-6 expression in M1 macrophages by 90.4% and 87.6%, respectively. The in vivo results demonstrate excellent biocompatibility and nearly complete wound healing within 15 days, with a residual wound area ratio of only 0.8%. This study establishes an on-demand exudate regulation and drug release mechanism for multifunctional dressings to accelerate wound recovery.

Abstract Eliminating reactive oxygen species (ROS) and inducing anti‐inflammatory M2 macrophages polarization are crucial for tissue repair. However, precisely regulating these processes in vivo is highly challenging. Despite small biomolecules and metal ions with ROS scavenging and M2 polarization potential, their high solubility hindered precise delivery, limiting therapeutic efficacy. This study proposes an innovative strategy involving the nanoscale and solidification of these molecules and ions to create pH‐responsive chlorogenic acid‐zinc nanoparticles. Leveraging macrophage's endocytosis and lysosomal acidity, these nanoparticles trigger precise metal ions and small molecules storm within 3 h after internalization, which effectively scavenges ROS and repairs damaged mitochondria. Additionally, it specifically inhibits the phosphorylation of NF‐κB p65 while activating the STAT6 signaling pathway within macrophages. This dual action reprograms macrophages toward the M2 phenotype, restoring immune homeostasis in the wound microenvironment. Notably, zinc ions probe is utilize to observe the dynamic process of the zinc ions storm and employed a series of mitochondrial‐related probes and transmission electron microscopy to validate the underlying mechanism of macrophage reprogramming through mitochondrial repair. The meticulously designed experiments on diabetic wound repair in mice fully validate these mechanisms, offering a universally applicable nanomedicine design approach for macrophage regulation and tissue repair.

Diabetic wound healing is a dynamic medical process that takes place in an environment within the body that is complex and contains elevated sugar levels, oxygen deprivation, and cellular oxidative stress. Phloridzin (Phlorizin) is one of the most well-known polyphenols found in apples because of its anti-inflammatory, antioxidant, antibacterial, antidiabetic, and antiseptic properties; it can also play a significant part in the healing of diabetic wounds. The study aimed to investigate the role of phloridzin as an efficient DPP-4 inhibitor with additional therapeutic effects in diabetic wound healing, as Dipeptidyl Peptidase-4 (DPP-4) expression increases in response to increases in glucose, Reactive Oxygen Species (ROS), and inflammation. Phloridzin inhibiting DPP-4 preserves Stromal cell-derived Factor-1α (SDF-1α), Insulin-like Growth Factor (IGF), and Glucagon-like Peptide-1 (GLP-1), which are possible DPP-4 substrates involved in wound healing. The accessible material from systemic searches in PubMed, Scopus, and published articles was reviewed with no period of limitation. The in silico study showed strong binding of phloridzin with DPP-4 protein (2P8S); also, in vitro DPP-4 inhibition assay has shown better inhibition by phloridzin. This study offers new research directions for examining phloridzin's capacity to withstand oxidative stress, as well as for redefining its tactical function as a powerful DPP-4 inhibitor to regulate the process involved in the healing of diabetic wounds.

Circular RNA-based therapy provides sustained and robust expression of FGF2 to accelerate diabetic wound healing.

Engineered heterojunction microneedles initiate ROS-mediated “two-hit” mechanism for accelerating impaired wound healing in diabetes

Chitosan/PVA nanofibrous membrane loaded with cerium manganese nanoparticles/SNAP promotes wound healing in diabetes

Local delivery of siRNA using lipid-based nanocarriers with ROS-scavenging ability for accelerated chronic wound healing in diabetes.

A multifunctional sodium alginate oxide-based hydrogel with antibacterial and anti-inflammation properties for smart monitoring and accelerated diabetic wound healing.