Strategy for Treatment of Infected Diabetic Foot Ulcers

A novel multifunctional self-assembled nanocellulose based scaffold for the healing of diabetic wounds

The healing of chronic diabetic wounds remains a key challenge due to its susceptibility to bacterial infection, the inflammatory wound microenvironment, and difficulty in angiogenesis. Herein, we devised a smart scaffold of nanocellulose with silk fibroin-loaded cerium oxide nanoparticles for the treatment of diabetic wounds. The smart scaffold dressing displays excellent porosity, water absorption, air permeability, water retention, controlled degradability, and antioxidant properties. In vitro experiments demonstrated that the scaffold was capable of promoting the degradation of the scaffolds through uncross linking and exhibited antibacterial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. Furthermore, in vivo experiments showed that smart scaffold dressing can reduces inflammation at the wound site of diabetic mice and promote collagen deposition, angiogenesis and re-epithelialization during wound healing in diabetic mice, exhibiting favorable biocompatibility and biodegradability. Its efficacy surpassed that of the current commercially available membrane dressings (3 M dressings) and medical PELNAC dressings (Class III medical device). These findings suggest that the smart scaffold dressing is a promising and innovative dressing for the treatment of diabetic wounds.

Microneedles loaded with l-arginine-modified puerarin-derived carbon nanoparticles improved treatment of diabetic wound via photothermal and nitric oxide-based gas therapy

Due to the high-glucose environment of diabetic wounds, a significant proliferation of bacteria at wound site can occur, resulting in an inflammatory response that extends the inflammatory phase of the wound, thereby complicating the healing process in diabetic wounds. Eliminating the proliferation of bacteria plays a crucial role in promoting the healing of diabetic wounds. Under near-infrared (NIR) laser irradiation, l-arginine (L-Arg) -modified natural product puerarin (Pue)-derived carbon nanoparticles (l-Arg-CNP) not only exhibited excellent photothermal effects but also produced reactive oxygen species (ROS) to react with l-Arg for producing Nitric Oxide (NO), thus contributing to a synergistic antibacterial therapy in diabetic wound. At the same time, l-Arg-CNP retained Pue's original characteristics to promote cell proliferation and angiogenesis. Following the loading of l-Arg-CNP into microneedle patches (l-Arg-CNP@MN), it can deliver them into the deeper wound, effectively killing bacteria, reducing inflammatory infiltration, and promoting neovascularization at the wound site. It offers an effective therapeutic strategy for treating diabetic wound healing.

Probing the antibacterial mechanism of Aloe vera based on network pharmacology and computational analysis

Bacterial resistance has emerged as a major clinical challenge globally. Natural products, such as Aloe vera, offer promising antimicrobial potential due to their diverse active components. However, the explicit molecular mechanisms remain unknown. In this study, we employed a multidisciplinary approach integrating network pharmacology, molecular docking, and molecular dynamics simulation to explore the antibacterial mechanism of Aloe vera. We screened the eight major active components of Aloe vera and their targets using multi-source bioinformatics platforms, identifying 55 targets closely associated with the antibacterial effects of Aloe vera. Protein-protein interaction network analysis, revealed potential crucial targets, including cysteine-aspartic acid protease-3 (CASP3) and matrix metalloproteinase-9 (MMP-9). Gene ontology functional enrichment analysis revealed that these targets play critical roles in several essential biological processes, such as "response to xenobiotic stimulus", "positive regulation of gene expression", and "collagen catabolism". The Kyoto Encyclopedia of Genes and Genomes signal pathway analysis indicated that these targets are primarily involved in pathways associated with cancer, lipid metabolism, atherosclerosis, and the AGE/RAGE signaling pathway in diabetes. This finding suggests that Aloe vera may exert its antibacterial effects by regulating the host's immune response and metabolism. Molecular docking and molecular dynamics simulations demonstrated that active ingredients of Aloe vera, such as quercetin and aloe-emodin, can form stable complexes with CASP3 and MMP-9, exhibiting vigorous binding affinity to the active sites of the target. Further antibacterial activity assays and reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis demonstrated that aloe-emodin exerts antibacterial effects against gram-positive bacteria and inhibits the expression of the MMP-9 gene. This study provided insight into the antibacterial mechanisms of Aloe vera, highlighting MMP-9 as a key target. These findings lay a foundation for further studies on natural antibacterial agents.

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.

Targeting m6A demethylase FTO to heal diabetic wounds with ROS-scavenging nanocolloidal hydrogels

Chronic diabetic wounds are a prevalent and severe complication of diabetes, contributing to higher rates of limb amputations and mortality. N6-methyladenosine (m6A) is a common RNA modification that has been shown to regulate tissue repair and regeneration. However, whether targeting m6A could effectively improve chronic diabetic wound healing remains largely unknown. Here, we found a significant reduction in mRNA m6A methylation levels within human diabetic foot ulcers, and the expression level of fat mass and obesity-associated protein (FTO) was significantly increased. We identified that m6A modifies the RNA of matrix Metalloproteinase 9 (MMP9), a key factor in diabetic wound healing, to regulate its expression. Importantly, we developed a ROS-scavenging nanocolloidal hydrogel loaded with an FTO inhibitor to increase the m6A level of MMP9 RNA in wounds. The hydrogel can effectively accelerate wound healing and skin appendage regeneration in streptozotocin-induced type I diabetic rats at day 14 (approximately 98 % compared to 76.98 % in the control group) and type II diabetic db/db mice at day 20 (approximately 93 % compared to 60 % in the control group). Overall, our findings indicate that targeting m6A with ROS-scavenging hydrogel loaded with FTO inhibitor may be an effective therapeutic strategy for diabetic wound healing.

An NIR-responsive "4A hydrogel" encapsulating wormwood essential oil: through antibacterial, antioxidant, anti-inflammation, and angiogenic to promote diabetic wound healing

The incorporation of hydrogels with biocompatible functional components to develop wound dressings exhibiting potent antibacterial, antioxidant, anti-inflammatory, and angiogenic properties to promote diabetic wound healing is highly desirable yet continues to pose a significant challenge. In this study, wormwood essential oil (WEO) is successfully encapsulated within black phosphorus (BP) using a physical extrusion technique. Subsequently, this composite is encapsulated within biocompatible gelatin methacrylate (GelMA) and hyaluronic acid methacrylate (HAMA) hydrogels to create multifunctional hydrogel dressing (WEO@BP/GH). In comparison to traditional hydrogels, BP enhances the encapsulation stability of WEO and improves the microenvironmental regulation capabilities through NIR-triggered release of WEO. Systemic in vitro experiments demonstrate that synergistic interaction between the diverse bioactive components of WEO and photothermal effects of BP results in highly effective antibacterial activities against S. aureus and E. coli, antioxidant of scavenging ROS, anti-inflammation of downregulating M1/M2 macrophages ratio, and angiogenic properties. Moreover, the in vivo tests demonstrate that WEO@BP/GH hydrogel significantly enhances high-performance diabetic wound repair through the acceleration of hemostasis, promotion of collagen deposition, regulation of inflammatory responses, and facilitation of vascularization. The findings indicate that WEO@BP/GH hydrogel holds considerable promise as a candidate for microenvironment regulation and effective diabetic wound healing across various clinical applications.

Fabrication and characterization of a multifunctional hyaluronic acid-based microneedle system for diabetic wound healing

Diabetes mellitus (DM)-associated wounds, characterized by chronic bacterial infections and elevated glucose levels, present significant challenges to effective healing. To overcome these issues, a novel transdermal drug delivery system was developed, integrating microneedles (MNs) with biofilm-penetrating capability, the wound-healing properties of hyaluronic acid (HA), the antibacterial effects of silver nanoparticles (AgNPs), and the glucose-lowering action of insulin (Ins). Named HAMNs@AgNPs-Ins, this system demonstrated optimal morphological characteristics, robust mechanical strength, and 100 % skin penetration efficiency. It exhibited sustained antibacterial activity in vitro, ensured skin safety, and provided controlled, steady blood glucose reductions, achieving a 72.29 % reduction at 8 h, compared to the sharp decline seen with subcutaneous injection. Additionally, wound healing experiments showed a significant improvement in the healing rate of 89.66 ± 1.34 % in the HAMNs@AgNPs-Ins group, compared to 48.19 ± 9.03 % in the control group. These results underscore the potential of HAMNs@AgNPs-Ins as an effective treatment for DM-associated wounds.

Gold nanoparticles modulate macrophage polarization to promote skeletal muscle regeneration

Skeletal muscle regeneration is a complex process that depends on the interplay between immune responses and muscle stem cell (MuSC) activity. Macrophages play a crucial role in this process, exhibiting distinct polarization states-M1 (pro-inflammatory) and M2 (anti-inflammatory)-that significantly affect tissue repair outcomes. Recent advancements in nanomedicine have positioned gold nanoparticles (Au NPs) as promising tools for modulating macrophage polarization and enhancing muscle regeneration. This review examines the role of Au NPs in influencing macrophage behavior, focusing on their physicochemical properties, biocompatibility, and mechanisms of action. We discuss how Au NPs can promote M2 polarization, facilitating tissue repair through modulation of cytokine production, interaction with cell surface receptors, and activation of intracellular signaling pathways. Additionally, we highlight the benefits of Au NPs on MuSC function, angiogenesis, and extracellular matrix remodeling. Despite the potential of Au NPs in skeletal muscle regeneration, challenges remain in optimizing nanoparticle design, developing targeted delivery systems, and understanding long-term effects. Future directions should focus on personalized medicine approaches and combination therapies to enhance therapeutic efficacy. Ultimately, this review emphasizes the transformative potential of Au NPs in regenerative medicine, offering hope for improved treatments for muscle injuries and diseases.

Milk-derived exosomes as functional nanocarriers in wound healing: Mechanisms, applications, and future directions

Wound healing presents a significant challenge in healthcare, imposing substantial physiological and economic burdens. While traditional treatments and stem cell therapies have shown benefits, milk-derived exosomes (MDEs) offer distinct advantages as a cell-free therapeutic approach. MDEs, isolated from mammalian milk, are characterized by their biocompatibility, ease of acquisition, and high yield, making them a promising tool for enhancing wound repair. This review provides a comprehensive analysis of the composition, sources, and extraction methods of MDEs, with a focus on their therapeutic role in both acute and diabetic chronic wounds. MDEs facilitate wound healing through the delivery of bioactive molecules, modulating key processes such as inflammation, angiogenesis, and collagen synthesis. Their ability to regulate complex wound-healing pathways underscores their potential for widespread clinical application. This review highlights the importance of MDEs in advancing wound management and proposes strategies to optimize their use in regenerative medicine.

Nanozyme-driven multifunctional dressings: moving beyond enzyme-like catalysis in chronic wound treatment

The treatment of chronic wounds presents significant challenges due to the necessity of accelerating healing within complex microenvironments characterized by persistent inflammation and biochemical imbalances. Factors such as bacterial infections, hyperglycemia, and oxidative stress disrupt cellular functions and impair angiogenesis, substantially delaying wound repair. Nanozymes, which are engineered nanoscale materials with enzyme-like activities, offer distinct advantages over conventional enzymes and traditional nanomaterials, making them promising candidates for chronic wound treatment. To enhance their clinical potential, nanozyme-based catalytic systems are currently being optimized through formulation advancements and preclinical studies assessing their biocompatibility, anti-oxidant activity, antibacterial efficacy, and tissue repair capabilities, ensuring their safety and clinical applicability. When integrated into multifunctional wound dressings, nanozymes modulate reactive oxygen species levels, promote tissue regeneration, and simultaneously combat infections and oxidative damage, extending beyond conventional enzyme-like catalysis in chronic wound treatment. The customizable architectures of nanozymes enable precise therapeutic applications, enhancing their effectiveness in managing complex wound conditions. This review provides a comprehensive analysis of the incorporation of nanozymes into wound dressings, detailing fabrication methods and emphasizing their transformative potential in chronic wound management. By identifying and addressing key limitations, we introduce strategic advancements to drive the development of nanozyme-driven dressings, paving the way for next-generation chronic wound treatments.

Injectable Polysaccharide-Based Hydrogel with Glucose Responsiveness as an Immunoregulatory Platform for Enhanced Diabetic Wound Healing

Persistent excessive inflammatory response in diabetic wounds caused by the imbalance of the immune microenvironment leads to delayed or nonhealing of the wounds. Timely attenuation of inflammation through immunoregulation is a crucial strategy to accelerate diabetic wound closure. Here, the protocatechuic acid (PCA)- and deferoxamine (DFO)-loaded polysaccharide-based immunoregulatory hydrogel (POCP@D) was developed by the dual-cross-linking strategy of borate ester bonds and imine bonds to promote advanced healing of full-thickness diabetic wounds. The POCP@D hydrogel showed good tissue adhesiveness property, flexibility, mechanical strength, injectability, self-healing, and glucose-responsive drug release properties, besides strong broad-spectrum antibacterial and antioxidant activities. The POCP@D hydrogel acted as an immunoregulatory platform to remold the in vivo immune microenvironment of diabetic wounds by regulating the M2-type macrophage polarization and timely relieving wound inflammation, thus promoting collagen deposition, angiogenesis, and the development of diabetic wounds from the inflammatory stage to the proliferative stage and ultimately achieving high-quality skin tissue regeneration. Overall, our developed immunoregulatory hydrogel held great potential for refractory diabetic wound therapy in clinical settings.

Stimulus-responsive nanomaterials for ocular antimicrobial therapy

Nanomaterials exhibit a promising new avenue for treating infectious keratitis, having garnered considerable interest in the ophthalmic medical community due to their unique properties including higher target specificity, enhanced bioactivity of loaded agents, reduced drug dosage, and stimulus-responsive drug release. These stimulus-responsive nanomaterial-mediated therapeutic strategies offer innovative approaches for managing ocular antimicrobial diseases. In this review, we aim to summarize current applications of stimulus-responsive nanotherapeutics for ocular antimicrobial therapy. We briefly introduce the basic ocular structure, ocular barrier, infectious keratitis classification, and its microenvironment. Following this, we summarize the nanotherapeutic antimicrobial strategies employed in treating ocular infections including endogenous stimulus-responsive ocular nanodrugs, sonodynamic therapy, and wearable device-based therapy, focusing on their design principles, developmental progress, and advantages and limitations. Finally, we critically evaluate the biosafety profiles of responsive nanomaterials, specifically addressing cytotoxicity and immune interactions. To conclude, we discuss key challenges in this research field and future opportunities with explicit emphasis on clinical translation and practical medical applications.

Guilongwan Ameliorates Experimental Diabetic Foot Ulcer in Rats via the Inhibition of Delta-Like 4/Notch1 Signaling in M1 Macrophages

Guilongwan (GLW), a representative of traditional Chinese Medicine (TCM) has been utilized to treating diabetic foot ulcer (DFU)-related syndrome including an intolerance of cold with cold limbs, blood circulation disorder, and immune dysfunction for decades. However, the chemical and biological mechanisms of GLW remain unclear. This study aims to discover the biological mechanisms of GLW on DFU by using streptozotocin- and skin-puncher-induced DFU rat models, in vitro macrophage models, and in silico analysis. The alterations in pathology, Notch1 signaling, and macrophage polarization are detected. The results indicated that GLW promoted wound healing, cutaneous cell proliferation, and angiogenesis in DFU rats by inhibiting delta-like (DLL) 4/Notch1 signaling. In addition, GLW inhibited M1 polarization and promoted M2 polarization in diabetic wounds. Seventeen chemical compounds in GLW-medicated serum are identified. In silico analysis and in vitro experiments demonstrated that GLW-medicated serum and its main compounds inhibited the expression of DLL4 in matrix metalloproteinase-9-induced M1 macrophages. In conclusion, GLW ameliorated experimental DFU rats via the inhibition of DLL4/Notch1 signaling in M1 macrophages. This study provided a new biologic mechanism for GLW in the treatment of DFU.

Targeting gut microbiota and its associated metabolites as a potential strategy for promoting would healing in diabetes

Impaired healing of diabetic wounds is one of the most important complications of diabetes, often leading to lower limb amputations and incurring significant economic and psychosocial costs. Unfortunately, there are currently no effective prevention or treatment strategies available. Recent research has reported that an imbalance in the gut microbiota, known as dysbiosis, was linked to the onset of type 2 diabetes, as well as the development and progression of diabetic complications. Indeed, the gut microbiota has emerged as a promising therapeutic approach for treating type 2 diabetes and related diseases. However, there is few of literatures specifically discussing the relationship between gut microbiota and diabetic wounds. This review aims to explore the potential role of the gut microbiota, especially probiotics, and its associated byproducts such as short chain fatty acids, bile acids, hydrogen sulfide, and tryptophan metabolites on wound healing to provide fresh insights and novel perspectives for the treatment of chronic wounds in diabetes.

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

Diabetic wound healing poses a significant clinical challenge with limited therapeutic efficacy due to uncontrolled reactive oxygen species (ROS), inflammatory responses, and extracellular matrix (ECM) degradation caused by abnormal macrophage activity in the wound microenvironment. To address these concerns, we propose a novel formulation that combines Tempo-conjugated lipid with the commercially cationic lipid DOTAP to expedite diabetic wound healing through targeted siRNA delivery (cLpT@siRNA) and restoration of the wound microenvironment. The developed cLpT@siRNA nanocomplexes effectively scavenge excessive ROS levels, facilitate polarization of proinflammatory M1 macrophages towards an anti-inflammatory M2 phenotype, and suppress MMP9 gene expression in macrophages. In the ICR mouse model of diabetic wounds, cLpT@siRNA nanocomplexes significantly accelerate wound healing, promoting neovascularization and collagen deposition. Overall, the cLpT@siRNA nanocomplexes based on antioxidant and cationic lipids provide a promising strategy for delivering siRNA in diabetic wound treatment and hold great potential for clinical translation.

Stimulus-responsive hydrogels for diabetic wound management via microenvironment modulation

Diabetic wounds, a major complication of diabetes mellitus, pose a significant clinical challenge. The treatment of diabetic wounds requires comprehensive interventions tailored to their pathophysiological characteristics, such as recurring bacterial infection, persistent inflammation, excessive oxidative stress, and impaired angiogenesis. The development of stimulus-responsive hydrogel dressings offers new strategies for diabetic wound treatment. By responding to various physical and biochemical signals, these smart hydrogels enable real-time monitoring and precise modulation of the wound microenvironment to accelerate diabetic wound healing. In this review, we provide an overview of the disease characteristics of chronic diabetic wounds and introduce the current clinical treatment approaches. We summarize the cutting-edge applications of physical and biochemical signal-responsive hydrogels for diabetic wound treatment by modulating the wound microenvironment.

Multifunctional nanocomposite hydrogels: an effective approach to promote diabetic wound healing

Diabetes, a metabolic disease that is becoming increasingly severe globally, presents a significant challenge in the medical field. Diabetic wounds are characterized by their chronicity, difficulty healing, and complex microenvironment that harbors multiple adverse factors, including elevated hyperglycemia, persistent inflammation, susceptibility to infections, and oxidative stress, all of which contribute to the impaired healing process. Nanocomposite hydrogels, as materials with unique physicochemical properties and biocompatibility, have gained growing attention in recent years for their potential applications in diabetic wound healing. These hydrogels provide a moist healing environment for wounds and regulate cellular behavior and signaling pathways, promoting wound repair and healing. By introducing specific functional groups and nanoparticles, nanocomposite hydrogels can respond to pathological features of wounds, enabling adaptive drug release. Owing to their diverse bioactive functions, nanocomposite hydrogels are powerful tools for the treatment of diabetic wounds. Thus, this article provides an overview of recent progress in the use of nanocomposite hydrogels for diabetic wound healing.

PVA/HA@BT hydrogel with antioxidant and antibacterial abilities for accelerating diabetic wound healing

Diabetic wound healing is severely hindered by prolonged oxidative stress and susceptibility to bacterial infections. To address this challenge, a dual-network hydrogel (PVA/HA@BT) was developed by integrating baicalein (BCE), a natural antioxidant, and tannic acid-stabilized silver nanoparticles (TA-AgNPs) into a polyvinyl alcohol/hyaluronic acid (PVA/HA) matrix. The hydrogel enables sustained BCE release to neutralize reactive oxygen species and alleviate oxidative damage, while synergistically enhancing antibacterial efficacy through the combined action of BCE and TA-AgNPs. In vitro studies demonstrated excellent biocompatibility, mechanical stability, and the ability to promote endothelial cell migration and tubule formation. In diabetic rat models, PVA/HA@BT significantly accelerated wound closure by reducing oxidative stress, suppressing bacterial growth, and enhancing tissue regeneration. This work provides a multifunctional therapeutic platform that synergizes antioxidant and antibacterial functions, offering a promising strategy for clinical diabetic wound management through the rational integration of natural bioactive components and nanomaterials.

Gene-engineered polypeptide hydrogels with on-demand oxygenation and ECM-cell interaction mimicry for diabetic wound healing

The treatment of infected diabetic wounds remains a significant clinical challenge due to pathogen infection, excessive inflammation, and impaired angiogenesis with troubled extracellular matrix (ECM) - cell and cell - cell interaction. Herein, we prepared a Janus polypeptide-engineered hydrogel with programmable function driven by self-assembly of the same A domain. The hydrogel was composed of a V8-degradable AC10A layer loaded with hybrid phages (ABC) for precise bacterial inhibition and a PC10ARGD layer loaded with Mn-based mineralized erythrocyte (PEM) for continuous supply oxygen on demand. The results of laser speckle contrast imaging, photoacoustic imaging, and hyperspectral imaging demonstrated that the AC10A@BP-Ce6/PC10AR@EM hydrogel (ABC/PEM) accelerated the reconstruction of normal skin structure by breaking the oxygen diffusion barrier and supplying oxygen on demand to promote angiogenesis and functionalization. In addition, in vitro and in vivo experiment results showed that the ABC/PEM hydrogel can mimic positive ECM - cell interaction to inhibit the polarization of macrophage towards M1-type to slow down the inflammatory process by down-regulated yes-associated protein (YAP), and relieve the mechanical tension of fibroblasts and keratinocytes. Finally, the ABC/PEM hydrogel promotes a healing rate of 98.83 % on day 21 and results in the number of dermal appendages being eight times that of the negative group. This work presents an effective strategy for diabetes-related chronic infected wound management.

Resveratrol Promotes Wound Healing by Enhancing Angiogenesis via Inhibition of Ferroptosis

Diabetic wound healing critically depends on functional endothelial cells for angiogenesis, yet the hyperglycemic microenvironment induces endothelial dysfunction through oxidative stress, inflammation, and senescence. Although ferroptosis has been recognized as a critical pathological factor contributing to impaired diabetic wound healing, the therapeutic potential of resveratrol (Res), a natural polyphenol with well-documented antioxidant and anti-ferroptotic properties, remains underexplored in this context. This study aimed to investigate the protective effects of Res on endothelial cells and elucidate its underlying mechanisms in diabetic wound healing. In vitro experiments systematically evaluated Res's impact on cellular inflammatory responses, senescence levels, and angiogenic capacity. Subsequent in vivo studies assessed Res's therapeutic potential by monitoring diabetic wound healing progression and analyzing associated histological changes. To clarify the mechanisms underlying Res's promotion of diabetic wound healing, we conducted comprehensive analyses measuring intracellular reactive oxygen species, lipid peroxidation levels, mitochondrial membrane potential and morphology, ferroptosis-related marker expression, and upstream signaling pathway regulation. Res significantly reduced HG-induced inflammatory responses and cellular senescence in human umbilical vein endothelial cells while enhancing their angiogenic potential in vitro. In vivo results showed that Res not only markedly accelerated diabetic wound healing but also demonstrated multiple beneficial effects, including effective suppression of cellular senescence, decreased ferroptosis levels, and significantly promoted angiogenesis. Mechanistic investigations confirmed that Res achieves these effects by inhibiting ferroptosis through activation of the PI3K-AKT-Nrf2 signaling axis. Our results demonstrate that Res protects endothelial cells from HG-induced ferroptosis by activating PI3K-AKT-Nrf2 signaling, thereby promoting angiogenesis and diabetic wound healing. These findings highlight Res as a promising therapeutic candidate for impaired diabetic wound repair and justify further clinical investigation.

A robust visualized sericin hydrogel dressing with excellent antioxidative and antimicrobial activities facilitates diabetic wound healing

Oxidative stress and infection significantly obstruct the process of diabetic wound healing. Herein, we developed a new sericin hydrogel with excellent antioxidative and antimicrobial features for the treatment of diabetic wounds. This hydrogel was prepared from a native sericin solution collected from silk fibroin-deficient mutant silkworm bodies; it also possesses exceptional ductility, high transparency, and excellent biocompatibility, enabling the hydrogel dressing to effectively eliminate excessive reactive oxygen species, while preventing bacterial infections within the diabetic wound microenvironment. Additionally, the hydrogel facilitates real-time monitoring of wounds and surgical sutures. Furthermore, it demonstrates pH-responsive swelling and degradation properties, along with a microporous structure, which collectively foster a moist, flexible, and breathable environment conducive to tissue regeneration, thereby promoting wound healing. Moreover, the hydrogel promotes the adhesion and proliferation of NIH3T3 cells, and in vivo studies highlight its ability to expedite wound healing. These findings suggest that the formic acid-treated sericin hydrogel dressing holds great promise as an advanced solution for managing diabetic wounds.

Calcium-ion-driving assembly of polysaccharide deriving from Zizyphus jujuba to hemostatic hydrogel for treating diabetic wound

Due to good biocompatibility and biodegradable, natural polysaccharide-based hydrogels have received worldwide attentions, where polysaccharide polymers were usually chemically modified to meet the specific elastic requirements. However, it remained highly challenging to develop polysaccharide-based hydrogels with desired mechanical properties and biological functions devoid of any structural modifications. Herein, with the coordination of Ca2+ (15.0 mM), the jujuba polysaccharide (JPS, 1 %) was facilely fabricated to a hydrogel (JPS-gel) within 1 min at pH 10, where the residual proteins also played crucial roles on the assembly. The JPS-gel showed outstanding stability and mechanical properties, which were tunable by adjusting the content of Ca2+/JPS. The JPS-gel also revealed excellent biocompatibility, and could expedite the migration and proliferation of healing-related cells, angiogenesis and alleviate inflammation response. More interestingly, the JPS-gel had hemostatic capacity, where the hemostatic time and blood loss in liver incision model were 13 ± 3 s and 6.3 ± 1.6 mg after 120 s treatment with JPS-gel, respectively. All these superiorities endowed JPS-gel high performance healing in diabetic wounds (10 days). Specially, the expressions of inflammation-related genes were downregulated, but gene expressions associated with cell migration and proliferation, and angiogenesis were upregulated, thus uncovering the action mechanism of JPS-gel on accelerating wound contraction.

Escherichia coli aggravates inflammatory response in mice oral mucositis through regulating Th17/Treg imbalance

Introduction

Microbial dysbiosis links to mucosal immune dysregulation, but the specific bacterial contributions to oral mucosal inflammation remain unclear. Escherichia coli (E. coli), a pathogen well-characterized in mucosal immunity and immune regulation studies, has been observed to be enriched in chronic oral inflammatory lesions and was reported to modulate T helper 17 cells (Th17)/T regulatory cells (Treg) homeostasis. Here, we developed an oral mucositis mouse model via tongue scratch and E. coli topical application to investigate its role in Th17/Treg imbalance.

Methods

The inflammatory infiltration was evaluated by macroscopic photography and HE staining. The expression of inflammatory factors in tongue tissue and peripheral blood of mice were detected by immunohistochemical staining and enzyme-linked immunosorbent assay. The number of Th17 and Treg in mice spleen lymphocytes were evaluated with flow cytometry. Differential gene expression analysis, functional enrichment analysis and immune infiltration analysis were performed using RNA-seq data from oral lichen planus (OLP).

Results

E. coli stimulation aggravated inflammatory responses induced by scratching in lingual mucosa of mice, including increased local and systemic expression of interleukin 6 (IL6), interleukin 17 (IL17), chemokine receptor 6 (CCR6) and chemokine C-C motif ligand 20 (CCL20), increased proportions of Th17 cells and increased Th17/Treg ratio in spleen lymphocytes. Analysis of RNA-seq data from OLP revealed alterations in antimicrobial responses and inflammatory factors associated with upregulation of Th17/Treg balance.

Conclusion

This study supports the role of E. coli in promoting oral mucosal inflammation and provides an experimental basis for in vivo study of OLP from the perspective of microorganisms.

Epigenetic silencing of SOD2 exacerbates mitochondrial oxidative stress and promotes pulmonary fibrosis

Mitochondrial oxidative damage-mediated dysfunction is implicated in pulmonary pathogenesis, yet the molecular mechanisms linking redox imbalance to pulmonary fibrosis remain elusive. In this study, we demonstrate that DNA methyltransferase 3 A (DNMT3A) drives fibroblast activation and pulmonary fibrosis by epigenetically repressing superoxide dismutase 2 (SOD2), a critical antioxidant enzyme. Using fibroblast-specific DNMT3A-deficient mice and bleomycin-induced pulmonary fibrosis models, we observed that DNMT3A ablation significantly attenuated mitochondrial oxidant overproduction, restored mitochondrial membrane potential (MMP), and reduced fibrotic progression. Mechanistically, DNMT3A directly bound to the SOD2 promoter, inducing hypermethylation and transcriptional silencing, which exacerbated oxidative stress and fibroblast proliferation. Conversely, AAV6-mediated SOD2 overexpression or DNMT3A knockdown rescued SOD2 expression, suppressed mitochondrial oxidative burden, and ameliorated fibrosis. Clinically, idiopathic pulmonary fibrosis (IPF) patient tissues exhibited elevated DNMT3A levels, diminished SOD2 expression, and marked mitochondrial dysfunction, corroborating our experimental findings. These results unveil a novel DNMT3A/SOD2 axis as an epigenetic regulator of mitochondrial redox dysregulation-driven fibrosis, providing a potential therapeutic avenue for targeting oxidative damage in pulmonary fibrotic disorders.

Microenvironment Self-Adaptive Ce-Ag-Doped Mesoporous Silica Nanomaterials (CA@MSNs) for Multidrug-Resistant Bacteria-Infected Diabetic Wound Treatment

Chronic wound healing remains a major challenge in diabetes management due to prolonged inflammation, autonomic neuropathy, and bacterial infections. In particular, multidrug-resistant bacterial infections are important to the development of diabetic wounds, leading to persistent inflammation and delayed healing. To address this issue, we developed a self-adaptive nanozyme designed to modulate infectious and inflammatory microenvironments by doping Ce and Ag into mesoporous silicon nanomaterials (MSNs). The resulting CA@MSNs exhibited strong bacterial capture capabilities via electrostatic attraction. Additionally, the synergistic effects of Ce and Ag endowed CA@MSNs with peroxidase (POD)-like activity, enabling the generation of reactive oxygen species (ROS) to eradicate bacteria in infectious microenvironments. Notably, CA@MSNs also demonstrated the ability to scavenge a broad spectrum of ROS, including hydroxyl free radicals, hydrogen peroxide, and superoxide radicals, in inflammatory microenvironments. This dual functionality helped mitigate inflammation and promote endothelial cell migration. Consequently, treatment with CA@MSNs significantly reduced inflammation, enhanced fibroblast activation, and facilitated collagen deposition, ultimately accelerating the healing of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds in diabetic mice. In conclusion, this study presents a promising therapeutic strategy for chronic diabetic wounds, offering a novel approach to overcoming infection-related healing delays.

pH and Glucose Dual-Responsive Hydrogels Promoted Diabetic Wound Healing by Remodeling the Wound Microenvironment

The microenvironment of diabetic wounds is complicated and characterized by hyperglycemia, hyperinflammation, persistent infection, hypoxia, and ischemia, making wound restoration and healing extremely challenging. Therefore, functional hydrogel dressings with the ability to regulate the microenvironment of diabetic wounds are a promising strategy for the treatment of diabetic wounds. In this study, a pH/glucose dual-responsive hydrogel based on phenylboric acid-modified carboxymethyl chitosan (CMCSPBA), aldehyde-terminated polyethylene glycol (PEGCHO), and polyvinyl alcohol (PVA) has been developed for diabetic wound treatment via Schiff base and phenylboric ester interactions. Glucose oxidase (GOX), catalase (CAT), and deferoxamine mesylate (DFO) are incorporated into the hydrogel to endow it with multi-functionality. In the hyperglycemic environment of diabetic wounds, a benign feedback loop is formed through the synergistic action of each component of the hydrogel, which enables the reshaping of the microenvironment of diabetic wounds by adjusting the pH and glucose, alleviating oxidative stress and hypoxia, regulating the inflammatory response, inhibiting bacterial infection, and promoting angiogenesis, thus accelerating diabetic wound healing in streptozotocin (STZ)-induced diabetic mice.

Low Serum Uric Acid Levels are Associated with Severe Diabetic Foot Infection: A Cross-Sectional Study from China

Diabetic foot ulcers (DFUs) are among the most serious complications of diabetes which are associated with high disability and mortality rates. This study aims to investigate the associations between uric acid (UA) levels and diabetic foot ulcer (DFU) characteristics. In total, 1820 participants with DFUs were included in this study; 192 and 1628 participants were included in the hyperuricemia group (HUA, UA > 420 µmol/L) and the nonhyperuricemia group (NHUA, UA ≤420 µmol/L), respectively. The NHUA group was divided into a middle-UA subgroup (SMUA, 420 µmol/L ≥ UA ≥ 180 µmol/L; 304 individuals) and a low-UA subgroup (SLUA, UA <180 µmol/L; 1324 individuals). There were no significant differences in the rates of deep ulcers, severe infection or amputation between NHUA and HUA. In univariate analysis of subgroups, the differences in the rates of deep ulcers, severe infection and amputation were significant. After adjusting for confounders (sex, fasting glucose level, diabetes duration, eGFR, deep ulcers and severe infection) in multivariate analysis, the severe infection rate (OR = 4.0, 95%CI 1.6-10.0, P < 0.01) was still significantly greater in the SLUA group than in the SMUA group while the rate of deep ulcers (OR =2.4, 95%CI 1.0-6.1, P = 0.06) and amputation (OR =1.1, 95%CI 0.3-4.3, P = 0.91) showed non-statistical difference. UA levels below 180 µmol/L can be a risk factor for severe infection in DFUs.

Advanced nanofibers integrating vitamin D3 and cerium oxide nanoparticles for enhanced diabetic wound healing: Co-electrospun silk fibroin-collagen and chitosan-PVA systems

This study investigates the co-electrospinning of polyvinyl alcohol-chitosan (PVA-CS) with cerium oxide nanoparticles (CeNPs) and silk fibroin-collagen (SF-Col) with vitamin D3 for diabetic wound healing applications. The SEM results showed smooth, bead-free nanofiber structures. The diameters of the SF-Col and PVA-CS nanofibers ranged from 168 ± 51 nm to 1956 ± 450 nm and 211.4 ± 37.2 nm, respectively. By surface modification using fetal bovine serum (FBS), CeNPs dispersion was enhanced. The average diameter of the uniformly distributed fibers on the SF-Co-D/PVA-CS-CeNPs nanofibers was 621.4 ± 50.6 nm. The addition of CeNPs and vitamin D3 improved cytocompatibility at lower doses. The FTIR test confirmed polymer interactions. Contact angle measurements indicated increased hydrophilicity. SEM analysis demonstrated excellent adhesion and growth of L929 fibroblast cells and significant HUVEC migration on SF-Col-D/PVA-CS-CeNP mats, emphasizing their potential to support cell proliferation and tissue regeneration. Blood compatibility assays exhibited hemolysis percentages below 2 %, classifying the nanofibers as non-hemolytic. Antibacterial tests revealed significant reductions in Staphylococcus aureus and Pseudomonas aeruginosa survival, addressing infection concerns in chronic wounds. Furthermore, in vivo studies have demonstrated that the utilization of SF-Co-D/PVA-CS-CeNPs nanofibrous membrane as a dressing for full-thickness skin wounds in rats has resulted in accelerated tissue regeneration.

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.

Transcriptome analysis of regenerated dermis stimulated by mechanical stretch

BACKGROUND

Mechanical stretch is utilized in the process of tissue expansion to promote skin regeneration, which is crucial for wound healing and organ reconstruction purposes. Enlarged dermal area is one of the significant histological characteristics of the expanded skin. However, the underlying biological processes and molecular pathways associated with dermal regeneration triggered by mechanical stretch are still not well understood.

METHODS

Twelve male Sprague-Dawley (SD) rats were divided into the expansion group and sham group randomly. Upon creating a rat scalp expansion model, the dermis was isolated from the full-thickness skin in both experimental groups for RNA sequencing. This process led to the identification of differentially expressed genes (DEGs). Subsequently, we conducted Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA) to identify the essential biological processes associated with dermal regeneration induced by mechanical stretch, leveraging data from the DEGs. A network of protein-protein interactions (PPI) was built to detect the critical modules and central genes. The expression levels of these hub genes were evaluated using quantitative real-time polymerase chain reaction (qPCR).

RESULTS

Increased expanded skin area and dermal thinning which represent the typical changes of expanded skin were observed in the expansion group. A total of 782 DEGs were identified in the expansion group relative to the sham group. The DEGs were associated with several biological processes, including the organization of the extracellular matrix, the enhancement of macrophage activation, and the promotion of angiogenesis, among others. Cell components encompassing Toll-like receptor 2-Toll-like receptor 6 protein complex, interstitial matrix, extracellular matrix (ECM), and collagen trimer were discovered. Molecular function categories including integrin binding, insulin-like growth factor binding, and fatty acid elongase activity were involved. The KEGG pathway analysis demonstrated the significant enrichment of pathways including the PI3K-Akt signaling pathway, fatty acid metabolism, and extracellular matrix-receptor interactions. GSEA results displayed that mechanical stretch correlated with the regulation of cell activation processes, cytokine-mediated signaling pathways, and immune system processes. PPI network resulted in the identification of 598 nodes along with a total of 5,304 interaction pairs between proteins. And ten hub genes containing Ccl2, Cxcl10, Fasn, Itgad, Cd163, Mmp9, Cd36, Tlr2, Igf1, and Wnt2 were identified by bioinformatics analysis and validated by qPCR.

CONCLUSIONS

This in vivo study for the first time revealed the DEGs related to mechanical stretch stimulated dermal regeneration and identified the involved pathways and hub genes correlated with macrophage recruitment and polarization, fibroblast proliferation and ECM production and angiogenesis, which may benefit further studies aimed at developing therapeutic strategies for facilitating expanded skin regeneration.

Natural, safety immunomodulatory derivatives of lactobacillus biofilms promote diabetic wound healing by metabolically regulating macrophage phenotype and alleviating local inflammation

INTRODUCTION

Long-term inflammatory microenvironment further impairs the healing process of diabetic wounds. Many studies have shown that Lactobacillus can regulate immune function and promote injured tissue repair. However, the immunomodulatory function and safety of Lactobacillus biofilm (LB) on wounds need further investigation.

OBJECTIVES

In this present research, we proposed a "bacteria-free biofilm derivative therapy" and successfully extracted Lactobacillus biofilm derivatives (LBDs) by ultrasonic separation and filtration technology for the natural and safe treatment of diabetic wounds.

METHODS

The study first cultured Lactobacillus anaerobically and extracted LBDs using ultrasound separation combined with filtration technology. LBDs were characterized via scanning electron microscopy, Concanavalin A fluorescence staining, and protein gel electrophoresis. In vivo diabetic wound model, wound closure rates were dynamically monitored, and tissue sections were analyzed using hematoxylin-eosin and immunofluorescence staining to evaluate LBDs' healing effects. An in vitro macrophage inflammation model was established, employing immunofluorescence, flow cytometry, and Western blotting techniques to explore the molecular mechanisms underlying LBDs' effects on macrophage phenotypes. Furthermore, whole-genome sequencing and proteomics of LBDs-treated macrophages were performed to further elucidate the intrinsic molecular mechanisms through which LBDs regulate macrophage phenotypes.

RESULTS

LBDs were effectively extracted utilizing ultrasonic separation coupled with filtration technology. Studies revealed that LBDs modulate the systemic metabolic reprogramming in wound-site macrophages, suppress JAK-STAT1 signaling pathway, alleviate the local inflammatory microenvironment, promote neovascularization and ultimately accelerate wound healing.

CONCLUSION

The LBDs retains most bioactive components of the LB. As a natural, safe and immunomodulatory agent, LBDs promote diabetic wound healing by metabolically reprogramming macrophage phenotypes and improving the local immune microenvironment, offering promising potential for regenerative applications in diabetic wound management.

Tβ4-exosome-loaded hemostatic and antibacterial hydrogel to improve vascular regeneration and modulate macrophage polarization for diabetic wound treatment

Diabetic wounds often exhibit delayed healing due to compromised vascular function and intensified inflammation. In this study, we overexpressed Thymosin β4 (Tβ4) in Adipose-Derived Stem Cells (ADSCs) to produce Exosomes (Exos) rich in Tβ4. We then utilized a dual photopolymerizable hydrogel composed of Hyaluronic Acid Methacryloyl (HAMA) and Poly-L-lysine Methacryloyl (PLMA) for the sustained release of Tβ4-Exos on diabetic wounds. The results showed that Tβ4-Exos could stimulate angiogenesis and collagen synthesis, and mitigate inflammation in diabetic wounds by promoting the polarization of M1-type macrophages and inhibiting that of M2-type macrophages. Furthermore, Tβ4-Exos was found to activate the PI3K/AKT/mTOR/HIF-1a signaling pathway, thereby enhancing vascular proliferation. In summary, the sustained release of Tβ4-Exos in HAMA-PLMA (HP) hydrogel and the management of inflammation through the upregulation of the HIF-1a pathway and modulation of macrophage polarization in vascular proliferation significantly accelerated the healing process of diabetic wounds.

Early Identification and Referral of Patients With Diabetic Foot Complications in the Emergency Department

BACKGROUND

Prolonged length of stay (LOS) in the emergency department (ED) and lack of post-ED follow-up pose a risk of worsening infection and amputation among patients with diabetic foot complications.

LOCAL PROBLEM

Excessive ED LOS posed a risk of delayed foot care, and triage providers underutilized post-ED telehealth referrals.

INTERVENTIONS

A graphic icon on the ED dashboard, nurse-initiated order set, and staff education were implemented.

METHODS

A pre-/postimplementation design was used. Outcomes included usage of the graphic icon and order set, ED LOS, and telehealth referrals.

RESULTS

Use of the graphic icon and order sets significantly increased ( P < .001). The rate of telehealth referrals upon discharge also increased but was not significant ( P = .086). Interestingly, LOS increased after the intervention.

CONCLUSION

Using the graphic icon and order set can streamline patient referral to telehealth care. Various factors lead to an extended LOS.

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.

Xanthium strumarium/gelatin methacryloyl based hydrogels with anti-inflammatory and antioxidant properties for diabetic wound healing via akt/mtor pathway

Chronic wound healing is often hindered by long-term inflammation and redox imbalance. Herbal medicine, with its rich medicinal components such as polysaccharides, flavonoids, phenolic acids, and small-molecule nutrients, has gained attention for its anti-inflammatory and antioxidant properties. Xanthium strumarium (XS) is a potent anti-inflammatory herb that has shown promise in treating conditions like rhinitis and may have specific benefits for chronic skin wounds. However, traditional XS preparations taken orally can have harmful effects on the liver and kidneys, limiting its clinical use. To date, there has been no documented method for the localized and sustained delivery of XS. This study introduces a timely development of a multifunctional hybrid hydrogel, incorporating bioactive XS extract and Gelatin Methacryloyl (GelMA), for the purpose of diabetic wound healing. In vitro experiments showed that XS/GelMA had strong anti-inflammatory and antioxidant effects through the Akt/mTOR pathway. The XS extract itself also significantly enhanced cell migration and angiogenesis. In vivo studies confirmed the superior wound healing properties of XS/GelMA. These findings suggest that XS-derived hydrogels have great potential for skin regeneration and tissue engineering applications.

A Smart MMP-9-responsive Hydrogel Releasing M2 Macrophage-derived Exosomes for Diabetic Wound Healing

Chronic diabetic wounds are characterized by prolonged inflammation and excessive accumulation of M1 macrophages, which impede the healing process. Therefore, resolving inflammation promptly and transitioning to the proliferative phase are critical steps for effective diabetic wound healing. Exosomes have emerged as a promising therapeutic strategy. In this study, a smart hydrogel capable of responding to pathological cues in the inflammatory microenvironment to promote the transition from inflammation to proliferation by delivering M2 macrophage-derived exosomes (M2-Exos) is developed. The smart hydrogel is synthesized through the cross-linking of oxidized dextran, a matrix metalloproteinase (MMP)-9-sensitive peptide, and carboxymethyl chitosan containing M2-Exos. In response to elevated MMP-9 concentrations in the inflammatory microenvironment, the hydrogel demonstrates diagnostic logic, adjusting the release kinetics of M2-Exos accordingly. The on-demand release of M2-Exos facilitated macrophage polarization from the M1 to the M2 phenotype, thereby promoting the transition from the inflammatory to the proliferative phase and accelerating diabetic wound healing. The transcriptomic analysis further reveals that the MMP-9-responsive hydrogel with M2-Exos delivery exerts anti-inflammatory and regenerative effects by downregulating inflammation-related pathways. This study introduces an innovative, microenvironment-responsive exosome delivery system that enables precise control of therapeutic agent release, offering a personalized approach for the treatment of chronic diabetic wounds.

Hydrogel dressing composed of nanoAg@QAC promotes the healing of bacterial infected diabetic wounds

Diabetes mellitus ranks as the eighth most prevalent cause of mortality and disability worldwide. It is a major challenge for clinics to treat diabetic-infected wounds. The hydrogel (referred to as NanoAg@QAC), which combines the advantages of nanosilver (NanoAg) and quaternary ammonium chitosan (QAC), possesses the characteristics of an ideal wound dressing, including proper mechanical properties, antimicrobial activity, anti-biofilm properties, and cytocompatibility. The NanoAg@QAC hydrogel proved to be efficacious in treating infections caused by S. aureus and P. aeruginosa in vivo, thereby promoting wound closure during the initial phase of healing. The application of the NanoAg@QAC hydrogel efficiently suppressed M1-type macrophage marker iNOS expression and simultaneously enhanced the M2-type macrophage marker CD206, which promoted the M1 to M2 transition. The hydrogel significantly reduced the pro-inflammatory cytokine interleukin-1β (IL-1β) and increased the levels of vascular endothelial growth factor A (VEGFA), which alleviated the inflammatory response of the wound and promoted neovascularization. Furthermore, the NanoAg@QAC hydrogel enhanced tissue regeneration and collagen deposition. Thisw study demonstrates that the NanoAg@QAC hydrogel exhibits significant potential for application in the treatment of diabetic-infected wounds.

Hydrogel inspired by "adobe" with antibacterial and antioxidant properties for diabetic wound healing

With the aging population, the incidence of diabetes is increasing. Diabetes often leads to restricted neovascularization, antibiotic-resistant bacterial infections, reduced wound perfusion, and elevated reactive oxygen species, resulting in impaired microenvironments and prolonged wound healing. Hydrogels are important tissue engineering materials for wound healing, known for their high water content and good biocompatibility. However, most hydrogels suffer from poor mechanical properties and difficulty in achieving sustained drug release, hindering their clinical application. Inspired by the incorporation of fibers to enhance the mechanical properties of "adobe," core-shell fibers were introduced into the hydrogel. This not only improves the mechanical strength of the hydrogel but also enables the possibility of sustained drug release. In this study, we first prepared core-shell fibers with PLGA (poly(lactic-co-glycolic acid)) and PCL (polycaprolactone). PLGA was loaded with P2 (Parathyroid hormone-related peptides-2), developed by our group, which promotes angiogenesis and cell proliferation. We then designed a QTG (QCS/TA/Gel, quaternary ammonium chitosan/tannic acid/gelatin) hydrogel, incorporating the core-shell fibers and the anti-inflammatory drug celecoxib into the QTG hydrogel. This hydrogel exhibits excellent antibacterial properties and biocompatibility, along with good mechanical performance. This hydrogel demonstrates excellent water absorption and swelling capabilities. In the early stages of wound healing, the hydrogel can absorb the wound exudate, maintaining the stability of the wound microenvironment. This hydrogel promotes neovascularization and collagen deposition, accelerating the healing of diabetic wounds, with a healing rate exceeding 95 % by day 14. Overall, this study provides a promising strategy for developing tissue engineering scaffolds for diabetic wound healing.

A calcitonin gene-related peptide co-crosslinked hydrogel promotes diabetic wound healing by regulating M2 macrophage polarization and angiogenesis

Delayed diabetic wound (DBW) healing is a severe complication of diabetes, characterized notably by peripheral sensory neuropathy. The underlying mechanism of sensory nerves and DBW remain unclear. Here, we demonstrate the role of calcitonin gene-related peptide (CGRP) in regulating epithelialization and angiogenesis in DBW. Subsequently, we design and synthesis a gelatin methacryloyl (GelMA-CGRP) hydrogel that slowly releases CGRP, and evaluated its effect on promoting DBW healing. The results show that CGRP is abnormally downregulated in DBW, and CGRP ablation further delays DBW healing. This is due to the reduced M2 polarization and decreased angiogenesis in the absence of CGRP, whereas local application of GelMA-CGRP accelerates DBW healing. Mechanistic studies indicate that CGRP promotes M2 macrophage polarization by inhibiting the p53 signaling pathway and enhances endothelial cell function, thereby accelerating DBW healing. These findings suggest that CGRP could provide a novel therapeutic approach for diabetic wound treatment. STATEMENT OF SIGNIFICANCE: Current methods for treating diabetic wounds have many limitations. Compared to conventional dressings, hydrogels combined with drugs or biological factors to promote diabetic wound healing have become an important research direction in recent years. This study reveals the key role of CGRP in the pathogenesis of diabetic wounds. The research found that CGRP promotes M2 macrophage polarization and angiogenesis by inhibiting the p53 signaling pathway, thereby promoting diabetic wound healing. We further utilized the carrier properties of GelMA hydrogel to develop a GelMA-CGRP hydrogel material that slowly delivers CGRP and effectively treats diabetic wounds. This material demonstrates strong biocompatibility and antimicrobial properties, offering a novel approach for the treatment of diabetic wounds.

Skin-Inspired and Self-Regulated Hydrophobic Hydrogel for Diabetic Wound Therapy

Diabetic wounds are refractory and recurrent diseases that necessitate the development of multifunctional dressings. Inspired by the structure and function of the skin, we herein delicately design a novel swollen hydrophobic hydrogel (QL@MAB) composed of hydrophobic methyl acrylate (MA) and (3-acrylamidophenyl)boronic acid (AAPBA) network and co-loaded with antioxidant quercetin (Q) and antibiotic levofloxacin (L) for efficient diabetic wound therapy. The hydrophobic MA segments undergo phase separation to form a dense "epidermis", ensuring prolonged drug diffusion, long-term water retention, and high water content. Meanwhile, the AAPBA segments generate glucose-labile "sweat pores" via borate ester bonds with the polyphenol drug Q. Upon encountering the hyperglycemic wound microenvironment, the "sweat pores" are dilated due to the cleavage of the borate ester bonds and exposure of the diffusion channel, facilitating drug release for accelerated wound healing. In the infected diabetic rats, QL@MAB achieves rapid wound debridement and re-epithelization while promoting angiogenesis, hair follicle regeneration, and extracellular matrix remodeling. Taken together, this study not only represents a multipronged dressing for effective interventions of diabetic wounds but also contributes to the rational design of smart hydrogels tailored for biomedical applications.

RNA N6-methyladenosine demethylase FTO promotes diabetic wound healing through TRIB3-mediated autophagy in an m6A-YTHDF2-dependent manner

N6-methyladenosine (m6A) RNA modification impaired autophagy results in delayed diabetic wound healing. In this study, it was found that fat mass and obesity-associated protein (FTO) was significantly downregulated in the epidermis of diabetic patients, STZ-induced mice and db/db mice (type I and II diabetic mice) with prolonged hyperglycemia, as well as in different types of keratinocyte cell lines treated with short-term high glucose medium. The knockout of FTO affected the biological functions of keratinocytes, including enhanced apoptosis, inhibited autophagy, and delayed wound healing, producing consistent results with high-glucose medium treatment. High-throughput analysis revealed that tribbles pseudokinase 3 (TRIB3) served as the downstream target gene of FTO. In addition, both in vitro and in vivo experiments, TRIB3 overexpression partially rescued biological functions caused by FTO-depletion, promoting keratinocyte migration and proliferation via autophagy. Epigenetically, FTO modulated m6A modification in the 3'UTR of TRIB3 mRNA and enhanced TRIB3 stability in a YTHDF2-dependent manner. Collectively, this study identifies FTO as an accelerator of diabetic wound healing and modulates autophagy via regulating TRIB3 in keratinocytes, thereby benefiting the development of a m6A-targeted therapy for refractory diabetic wounds.

Biomimetic gene delivery system coupled with extracellular vesicle-encapsulated AAV for improving diabetic wound through promoting vascularization and remodeling of inflammatory microenvironment

Adeno-associated virus (AAV)-mediated gene transfer has demonstrated potential in effectively promoting re-epithelialization and angiogenesis. AAV vector has a safety profile; however, the relatively low delivery efficacy in chronic wound with an inflammatory microenvironment and external exposure has limited its prospective clinical translation. Here, we generated AAV-containing EVs (EV-AAVs) from cultured HEK 293T cells and confirmed that the gene transfer efficiency of VEGF-EV-AAV significantly surpassed that of free AAV. Subsequently, a biomimetic gene delivery system VEGF-EV-AAV/MSC-Exo@FHCCgel developing, and synergistically enhances anti-inflammation and transfection efficiency in the combination of human umbilical cord mesenchymal stem cell-derived exosomes (hUC-MSC-Exo). Upon reaching physiological temperature, this hydrogel system transitions to a gel state, maintaining AAV bioactivity and facilitating a sustained release of the encapsulated vesicles. The encapsulation strategy enables the vesicles to rapidly fuse with endothelial cell membranes, ensuring controlled expression of endogenous VEGF. Results revealed that VEGF-EV-AAV/MSC-Exo@FHCCgel alleviates mitochondrial function in endotheliocyte under oxidative stress. Furthermore, it eliminates senescent macrophages by inhabitation of cyclic GMP-AMP (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway to promote efferocytosis. The system increases Treg cells accumulation, leading to a reduction of inflammatory cytokines. Collectively, the biomimetic gene delivery system represents a promising multi-faceted strategy for chronic wound healing.

A multiple-crosslinked injectable hydrogel for modulating tissue microenvironment and accelerating infected diabetic wound repair

Elevated oxidative stress and inflammation, bacterial infections, and vascular impairment undoubtedly impede the normal diabetic wound healing process, which has encouraged the development of high-performance dressings for wound management. Herein, a new type of multiple-crosslinked injectable hydrogel, GCP, was developed via the radical polymerization of propenyl groups and the formation of copper‒polyphenol coordination bonds and Schiff base bonds. The copper‒polyphenol coordination and Schiff base bonds in the GCP hydrogel were disrupted in the acidic microenvironment of diabetic wound, resulting in the release of copper ions and protocatechualdehyde (PA) to scavenge reactive oxygen species (ROS), promote angiogenesis and cell migration, and exert antibacterial and anti-inflammatory activities via the CuPA complexes. Consequently, markedly accelerated infected diabetic wounds healing was achieved through this tissue microenvironment remodeling strategy. Moreover, the underlying mechanism of the antibacterial properties was investigated by 16S rRNA sequencing. The results indicated that the CuPA complexes can clearly inhibit the growth and reproduction of S. aureus by downregulating specific genes associated with ABC transporters, hindering bacterial protein synthesis, and enhancing oxidoreductase activity. This innovative hydrogel platform for wound management may inspire new methods for the preparation of high-performance biomedical materials and the treatment of other clinical diseases.

Skin regenerative potential of hydrogel matrices incorporated with stem cell-derived extracellular vesicles enriched with MicroRNAs: a systematic review

Stem cell-derived extracellular vesicles (SC-EVs) are one huge promise in skin regenerative medicine, similar in advantages to stem cells with low immunerejection and tumor formations. These microvesicles are laden with microRNAs, which assist in wound healing via angiogenesis and immune modulation. However, quick degradation and poor cellular uptake limit their regenerative capacity. Thanks to their adjustable characteristics, hydrogels can act as vehicles for transporting and sustainably releasing miRNA-SC-EVs at injury sites. Therefore, a systematic literature review was conducted on miRNA-enriched SC-EVs incorporated into hydrogels in animal skin regeneration models published from 2010 to 2024 (PROSPERO ID: CRD42024588072). Out of the 89 records, 12 met the criteria. Diabetic wounds are characterized by chronic inflammation, oxidative stress, and defective macrophage polarization, resulting in less satisfactory regeneration. The hydrogels tackled these issues by shifting macrophages from a pro-inflammatory M1 phenotype to a healing M2 phenotype, promoting collagen production, enhancing fibroblast movement, and boosting angiogenesis. Burn injuries frequently lead to slow recovery due to hypertrophic scarring, extended inflammation, and infection. Hyaluronic acid (HA)-derived hydrogels, infused with miR-21-5p and surface-treated with polydopamine and cationic antimicrobial peptides, promoted wound healing by lowering scarring and demonstrating anti-inflammatory, anti-apoptotic, and pro-angiogenic characteristics. The cell adhesion of these hydrogels can be enhanced by adding MOFs, chitosan, and extracellular matrix elements. The application of stimulus-responsive or stage-specific hydrogels is another mode of targeted healing. Further research and clinical trials will enhance the wound-healing efficiency of hybrid hydrogels.

Responsive hydrogel modulator with self-regulated polyphenol release for accelerating diabetic wound healing via precise immunoregulation

Nonhealing chronic wounds are intractable clinical complications of diabetes and are characterized by high protease activity, severe oxidative stress and sustained inflammatory response. In this case, the development of functional hydrogel dressings to modulate the immune microenvironment is a well-known strategy, where the precise stimuli-responsive and spatiotemporally controlled release of bioactive molecules remains a huge challenge. Herein, we developed responsive hydrogels with self-regulated bioactive molecule release based on the protease activity in diabetic wound sites, to serve as a smart immune microenvironment modulator for accelerating wound healing. The hydrogels were fabricated by grafting oxidized hyaluronic acid with epigallocatechin-3-gallate (EGCG) and gelatin methacryloyl (GelMA) under UV irradiation. Resveratrol nanoparticles were further loaded into the hydrogels before gelation to construct a polyphenol delivery system. The prepared hydrogels could achieve the on-demand release of polyphenol upon degradation by protease, as confirmed via degradation and polyphenol release experiments. The released polyphenol was demonstrated to have the capacity to effectively scavenge excessive free radicals, promote macrophage polarization, reduce proinflammatory factor (TNF-α) expression and augment anti-inflammatory factor (IL-10) expression in vitro. Additionally, in vivo rat wound healing model experiment results confirmed that these hydrogels promoted collagen deposition and granulation tissue regeneration, accelerating diabetic wound healing. Based on the protease-responsive degradation characteristic of the hydrogels and high protease activity in the diabetic wound microenvironment, hydrogels with exquisite polyphenol release controllability are promising candidates as dressings for diabetic wound management.

Network Pharmacology, Molecular Docking and Experimental Validation on Potential Application of Diabetic Wound Healing of Cinnamomum zeylanicum Through Matrix Metalloproteinases-8 And 9 (MMP-8 And MMP-9)

Background

Diabetic wounds are a significant clinical challenge due to impaired healing processes often exacerbated by elevated matrix metalloproteinases (MMPs). Cinnamomum zeylanicum, known for its anti-inflammatory and antioxidant properties, has shown potential in promoting wound healing. This study investigates the molecular docking and experimental validation of Cinnamomum zeylanicum's effects on diabetic wound healing, focusing on its interaction with matrix metalloproteinases-8 (MMP-8) and 9 (MMP-9).

Methods

Molecular docking studies were performed to predict the binding affinity of Cinnamomum zeylanicum compounds to MMP-8 and MMP-9. Diabetic wound healing was evaluated using in vivo models where wounds were induced and treated with Cinnamomum zeylanicum extract. Various parameters were measured, including wound contraction, hydroxyproline content, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels. Biochemical analyses included glucose levels, fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and histomorphological examination of skin tissues.

Results

Molecular docking results indicated a high binding affinity of Cinnamomum zeylanicum's bioactive compounds with MMP-8 and MMP-9, suggesting potential inhibition. Experimental validation showed significant improvement in wound contraction and increased hydroxyproline content, indicating enhanced collagen synthesis. Antioxidant enzyme activities (SOD, GPx, CAT) were significantly elevated, while MDA levels were reduced, reflecting decreased oxidative stress. Biochemical analysis demonstrated improved glucose homeostasis with reduced FBG and enhanced OGTT responses. Histomorphological studies revealed improved tissue architecture and re-epithelialization in treated wounds.

Conclusion

Cinnamomum zeylanicum exhibits promising potential in diabetic wound healing by modulating MMP-8 and MMP-9 activities, enhancing antioxidant defenses, and improving glucose regulation. These findings support its therapeutic application for diabetic wounds, providing a foundation for further clinical investigations.

A Semi-Interpenetrating Network Hydrogel with Excellent Photothermal Antibacterial and ROS Scavenging Activities for MRSA-Infected Wounds

The prolonged infection of bacteria at the wound site may lead to serious physical problems. Herein, a multifunctional macroporous hydrogel with superior photothermal antibacterial and ROS scavenging activity (denoted as M-XG gel) was designed for the treatment of MRSA-infected wounds. The M-XG gels are composed of embedding Prussian blue nanoparticles (PBNPs) as photothermal converters and chelating ferric ions with xanthan gum (XG) and dopamine (DA) to form a semipermeable network. The introduction of DA occupies the cross-link sites of ferric ions, further increasing the pore size (200-500 μm open macropores) and endowing the hydrogel with ideal adhesion. The increase of cross-link sites in PBNPs formed a promising equilibrium M-XG gel with identical macroporous structures and toughened mechanical performance. The metal ligands between ferric ions and catechols, as well as the unique photothermal response of PBNPs, endow the hydrogels with a fast and stable near-infrared (NIR) photothermal conversion efficiency (48%). In the MRSA-infected SD rat trauma model, wounds treated with the M-XG gel group had completely closed after 14 days, effectively controlling wound bacterial infection and accelerating angiogenesis and collagen deposition, synergistically promoting infected wound healing. Therefore, the photothermal hydrogel with a semi-interpenetrating network demonstrates its great potential for infected wound tissue engineering.

Conditioned medium of engineering macrophages combined with soluble microneedles promote diabetic wound healing

Diabetic wounds have a profound effect on both the physical and psychological health of patients, highlighting the urgent necessity for novel treatment strategies and materials. Macrophages are vital contributors to tissue repair mechanisms. Macrophage conditioned medium contains various proteins and cytokines related to wound healing, indicating its potential to improve recovery from diabetic wound. Engineering macrophages may enable a further improvement in their tissue repair capacity. Fibroblast growth factor 2 (FGF2) is a crucial growth factor that plays an integral role in wound healing process. And in this study, a stable macrophage cell line (engineered macrophages) overexpressing FGF2 was successfully established by engineering modification of macrophages. Proteomic analysis indicated that conditioned medium derived from FGF2 overexpressed macrophages may promote wound healing by enhancing the level of vascularization. Additionally, cellular assays demonstrated that this conditioned medium promotes endothelial cell migration in vitro. For the convenience of drug delivery and wound application, we prepared soluble hyaluronic acid microneedles to load the conditioned medium. These soluble microneedles exhibited excellent mechanical properties and biocompatibility while effectively releasing their contents in vivo. The microneedles significantly accelerated wound healing, leading to a marked increase in vascular proliferation and improved collagen deposition within a full thickness skin defect diabetic mouse model. In summary, we developed a type of hyaluronic acid microneedle loaded with conditioned medium of engineered macrophages. These microneedles have been demonstrated to enhance tissue vascularization and facilitate diabetic wound healing. This might potentially serve as a highly promising therapeutic approach for diabetic wounds.

Tailored Metal-Phenolic Network with Hypoglycemic Polyphenol for Promoting Diabetic Wound Healing

Diabetic foot ulcer is a common and serious complication of diabetes, with a high risk of amputation, recurrence, and mortality. Aiming at the characteristics of diabetic wounds and based on the result of network pharmacology, a tailored ligand cyanidin-3-O-glucoside (C3G) was selected to construct a metal-phenolic network (CM) through the self-assembly reaction with manganese ions. CM integrates the pharmacological advantages of C3G in antidiabetes and the anti-inflammatory activity of metal-phenolic networks by simulating the metal coordination structure of antioxidant enzymes. Reasonably, the wound areas of db/db mice with CM treatment rapidly decreased to 3.06% at day 14, accompanied by the improvement of tissue microenvironment. Mechanism investigation indicated that CM can not only reduce inflammation activation and immunoreaction but also increase gene transcripts in glucose metabolism, response to hypoxia, and angiogenesis. It is believed that this work opens a way for designing disease-specific metal-phenolic networks, and the CM with high biosafety promotes the clinical treatment of diabetic wounds.

Electrospinning in promoting chronic wound healing: materials, process, and applications

In the field of wound treatment, chronic wounds pose a significant burden on the medical system, affecting millions of patients annually. Current treatment methods often fall short in promoting effective wound healing, highlighting the need for innovative approaches. Electrospinning, a technique that has garnered increasing attention in recent years, shows promise in wound care due to its unique characteristics and advantages. Recent studies have explored the use of electrospun nanofibers in wound healing, demonstrating their efficacy in promoting cell growth and tissue regeneration. Researchers have investigated various materials for electrospinning, including polymers, ceramics, carbon nanotubes (CNTs), and metals. Hydrogel, as a biomaterial that has been widely studied in recent years, has the characteristics of a cell matrix. When combined with electrospinning, it can be used to develop wound dressings with multiple functions. This article is a review of the application of electrospinning technology in the field of wound treatment. It introduces the current research status in the areas of wound pathophysiology, electrospinning preparation technology, and dressing development, hoping to provide references and directions for future research.