Three-dimensional gelatin sponge culture potentiates MSC secretome to enhance full-thickness wound healing and induce hair follicle neogenesis via Wnt/β-catenin and TLR3/STAT3 activation in rats.

BackgroundHyaluronic acid, as a natural extracellular matrix component, possesses excellent biocompatibility and moisturizing properties, and demonstrates unique advantages in wound repair.ObjectivesTo explore the role of hyaluronic acid methacryloyl (HAMA) hydrogels in skin wound healing and analyze the characteristics of the local microenvironment of wounds.MethodsMice divided into a control group (n = 6) and a HAMA group (n = 6) at random were used to create a model of total cortical resection. 100μL of HAMA hydrogel was applied to the wound surface in the HAMA group, while 100 μL of lithium phenyl-2,4,6-trimethylbenzoyl hypophosphonate (LAP) was applied to the wound surface in the control group. Both were irradiated with an ultraviolet lamp for 20 seconds, and on days 0, 3, 7, 10, and 14, the residual wounds were measured. The effect of the HAMA hydrogel on wound healing was analyzed by measuring the remaining wound area and performing hematoxylin-eosin (H&E) staining. The cellular characteristic spectrum of the local skin of the wound on the 14th day was analyzed via single-cell sequencing technology, and the degree of type I and type III collagen expression, F4/80, CD206 and CD86 in the local wound were detected via immunohistofluorescence technology. The mRNA expression levels of Arg1, Nos2, Itgam and Itgb2 in the RAW264.7 mouse macrophage line coincubated with the HAMA hydrogel for 24 hours were detected by RT-qPCR. Cluster analysis of fibroblasts and macrophages in the local skin of the wounds on the 14th day in mice was conducted via the Seurat software package, and the communication status between fibroblasts and macrophages was analyzed via the CellChat software package.ResultsThe HAMA group's skin wounds healed considerably more quickly than the control group's did. While the wounds in the control group had not yet fully healed, those in the HAMA group had by the fourteenth day. Single-cell sequencing analysis revealed that the proportion of fibroblast subsets with high expression of Col3a1 in the HAMA group (90.2%) was greater than that in the control group (79.8%), whereas the proportion of fibroblast subsets with high expression of Colla1 (5.7%) was lower than that in the control group (15.9%). The results of the immunofluorescence analysis confirmed that the local type III collagen level in the wounds of the HAMA group was greater than that in the wounds of the control group (P = 0.035), whereas the type I collagen level was lower than that in the wounds of the control group (P = 0.044). There was no significant difference in the proportion of local macrophages on the wound surface between the HAMA group mice and the control group mice. However, both the single-cell sequencing analysis results and the in vitro treatment of Raw264.7 macrophages with the HAMA hydrogel revealed increased expression of Arg1 (P < 0.001) and decreased expression of Nos2 (P < 0.001). Moreover, in the HAMA group, macrophages at the wound site expressed higher levels of CD206 (P = 0.042) and lower levels of CD86 (P = 0.011).ConclusionsTreatment of the microenvironment with the HAMA hydrogel is conducive to the healing of skin wounds, and more anti-inflammatory macrophages and fibroblasts that secrete type III collagen accumulate locally in the wound healing tissue.

Exosomes serve as intercellular communication vectors and are involved in a broad range of physiological functions. Although exosome-based therapies have demonstrated diverse functional potential, the regulatory mechanisms underlying their biogenesis and secretion remain poorly understood. Here, we report that TEAD1 functions as a molecular switch, dramatically enhancing the synthesis and secretion of exosomes. Mechanistically, TEAD1 enhances exosome secretion by promoting the expression of exosome secretion-associated proteins RAB11, CD9, and SNAP23. We found that TEAD1 enhances exosome secretion from adipose-derived mesenchymal stem cells, thereby promoting skin wound healing in diabetic mice. Similarly, TEAD1 promotes the release of exosomes from bone marrow-derived mesenchymal stem cells, thereby facilitating spinal cord injury (SCI) repair. Our study elucidates a novel role for TEAD1 in driving exosome secretion in different cell types, highlighting the therapeutic potential of TEAD1 in enhancing tissue regeneration, particularly in diabetic wound healing and SCI repair.

Forsythia suspensa accelerates wound healing by inhibiting neutrophil extracellular traps and activating Wnt/β-catenin via forsythoside A.

Oxidative stress limits mesenchymal stem cell (MSC) efficacy in tissue repair by reducing retention and survival at injury sites. Endogenous production of trehalose may enhance MSC resilience and promote skin wound healing. Trehalose-6-phosphate synthase 1-expressing MSCs (TPS1-MSCs) were engineered via adenoviral transduction. Trehalose content and synthase activity were assessed. Oxidative stress models (H2O2, 0% fetal bovine serum, CoCl2) were used to evaluate reactive oxygen species (ROS), apoptosis, and cell damage. TPS1-MSCs were transplanted into mouse wounds to track retention rate via invivo imaging. Histology and immunofluorescence were used to assess wound healing, collagen deposition, and angiogenesis. Conditioned medium (CM) was used to evaluate paracrine functions. RNA-seq identified differentially expressed genes, and mechanisms were validated using the NRF2 inhibitor ML385. TPS1-MSCs exhibited TPS1 activity and synthesized trehalose. Under oxidative stress, these cells showed reduced ROS, enhanced viability, and decreased apoptosis. In vivo, TPS1-MSCs displayed higher retention, accelerated healing, and neovascularization. CM from TPS1-MSCs promoted keratinocyte migration, fibroblast collagen secretion, and enhanced the tube-forming capacity of endothelial cells. Transcriptome analysis revealed enrichment in the NRF2-HMOX1 pathway. TPS1-MSCs showed elevated levels of p62, nuclear NRF2, and HMOX1. ML385 treatment impaired the observed antioxidant capacity. Engineering MSCs for endogenous trehalose synthesis enhanced oxidative stress resistance and retention through NRF2-HMOX1 activation, suggesting a potential novel MSC-based wound repair strategy. TPS1-MSCs improved antioxidant capacity and wound healing, potentially through the NRF2-HMOX1 pathway, and may represent a promising therapy for skin wounds. [Figure: see text] [Figure: see text].

Molecular mechanisms of Cornua Cervi Degelatinatum extract in promoting skin wound healing: Insights from transcriptomics and multi-model validation.

During the healing of skin wounds, excessive fibrosis and collagen remodeling disorders often lead to the formation of proliferative scars. Fisetin is a naturally occurring flavonoid compound with antioxidant and anti-fibrotic properties. However, its therapeutic effect and mechanism of action in wound healing and inhibition of scar formation are still unknown. This study used network pharmacological methods to identify potential targets and pathways related to wound healing and proliferative scar formation. Through protein-protein interaction analysis, Gene Ontology analysis and enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG), its potential biological functions were clarified. In addition, molecular docking was also carried out to evaluate the binding affinity between fisetin and the core target. The effect of fisetin on wound closure and collagen deposition was evaluated using the full-thickness skin wound model in rats. In in vitro experiments, human dermal fibroblasts were used to study the effect of fisetin on collagen expression and the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Network pharmacological analysis highlighted serine/threonine kinase 1 (AKT1) as a central target linking fisetin to wound repair and fibrosis. Functional enrichment indicated significant involvement of the PI3K/Akt pathway. Molecular docking further confirmed a strong binding affinity between fisetin and AKT1. In vivo experiments demonstrated that fisetin significantly accelerated wound closure, reduced inflammatory cell infiltration, and improved histological organization. Quantitative analysis showed decreased histological inflammation scores and a reduced the ratio of type I collagen (COL1A)/type III collagen (COL3A), indicating improved collagen remodeling and attenuated scar formation. Moreover, fisetin upregulated PTEN expression while suppressing transforming growth factor-beta1 (TGF-β1) and alpha-smooth muscle actin (α-SMA) expression in wound tissues. In vitro experiments further confirmed that fisetin inhibited profibrotic marker expression and regulated PI3K/Akt signaling activity in HDFs. Fisetin promotes skin wound healing and attenuates proliferative scar formation by reducing inflammation, improving collagen remodeling, and suppressing fibrotic signaling. Mechanistically, fisetin upregulates PTEN and inhibits the PI3K/Akt/TGF-β1 axis, thereby limiting fibroblast activation and pathological extracellular matrix deposition. These findings suggest fisetin as a promising therapeutic candidate for wound management and scar prevention.

Chronic wounds caused by multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) often stall during the healing process due to persistent inflammation and failed tissue repair. This pathological state primarily results from a vicious cycle formed by the interaction of oxidative stress, chronic inflammation, and impaired angiogenesis. To this end, this study employs network pharmacology to reveal that gallic acid (GA, a polyphenol with potent antioxidant and anti-inflammatory activity) promotes skin wound healing by regulating oxidative stress and apoptosis. Subsequently, based on these findings, a dynamic hydrogel dressing with cascade enzyme-like activity was developed. By synergistically modulating the oxidative stress microenvironment, eliminating bacterial infections, promoting angiogenesis, and accelerating the healing of MRSA-infected wounds, it effectively remodels the wound microenvironment. The core of this system is a metal-phenolic network particle (ZCG) self-assembled from Zn2+ (antibacterial), Cu2+ (angiogenic), and GA. These bioactive particles are embedded in a dynamic hydrogel matrix composed of oxidized fucoidan (OFD) and carboxymethyl chitosan (CMCS), which confer self-healing and injectable properties to the dressing. Simultaneously, by synergistically combining metal ions and GA, the hydrogel dressing functions as a "regenerative niche" that effectively eradicates MRSA. It further scavenges excess reactive oxygen species to alleviate inflammation and protect host cells. The system also releases pro-angiogenic copper ions to reconstruct vascular networks, effectively remodeling the wound microenvironment. This promotes collagen deposition and granulation tissue formation, accelerating wound closure. As a universal therapeutic solution for chronic nonhealing wounds, it holds significant clinical translation potential.

The skin, the largest organ in the human body, serves as a crucial barrier against external stimuli. With the acceleration of social industrialization and the worsening of global climate change, the risk of physical, chemical and biological damage to the skin has significantly increased. Among these, surgical wounds, accidental injuries, diabetic wounds, and ultraviolet (UV)-radiation-induced photoaging are particularly common. Cutaneous wound healing is a complex and dynamic process that requires precise coordination of numerous molecular events to effectively repair damaged skin. Skin photoaging, a phenomenon of premature aging caused by long-term UV exposure, is characterized by pigmentary abnormalities, telangiectasia, epidermal roughness, wrinkle formation, and precancerous lesions, all of which seriously affect skin health and appearance. Extracellular vesicles (EVs), a class of nano-sized vesicles secreted by various cells, play important regulatory roles in tissue regeneration. Although cell-culture-medium-derived EVs (C-EVs) have been proven to effectively promote skin wound healing and photodamage repair, their origin from a single cell type and challenges in large-scale production severely limit their broad application. In contrast, EVs derived from natural biological resources, including tissue-derived EVs (Ti-EVs) and plant-derived EVs (PDEVs), have emerged as novel therapeutic strategies for skin wounds and photoaging. These EVs better reflect the physiological microenvironment and demonstrate considerably higher production efficiencies. Ti-EVs, obtained from mammalian tissues composed of multiple cell types and extracellular matrix, contain more abundant regulatory factors, thus exhibiting superior bioactivity compared with C-EVs. PDEVs have also garnered significant attention due to their favorable stability, low immunogenicity, unique natural antioxidant components, and feasibility of large-scale extraction. This review will systematically elaborate on the characteristics and isolation methods of both Ti-EVs and PDEVs, as well as their therapeutic roles and underlying mechanism in wound healing and skin photoaging.

The number of pet dogs is increasing, and the number of working dogs (e.g., guide dogs, police dogs) is also gradually increasing. Skin wounds are a common clinical problem in dogs and tend to be more common in the clinic as mechanical wounds. The healing process of skin wounds is often influenced by a variety of factors, including infection, nutritional status, and immune response, while wound healing is more difficult in dogs with diabetes or aging dogs. Mesenchymal stem cells (MSCs) play an important role in skin healing and regeneration with their multidirectional differentiation potential and immunomodulatory function. However, the application of MSCs alone for the treatment of skin wounds may have certain limitations, such as low cell survival and a lack of localization. Therefore, it is important to find methods that can enhance the therapeutic effect of MSCs. Secreted protein acidic and rich in cysteine (SPARC), an extracellular matrix protein widely involved in regulating biological processes such as cell proliferation, migration, and matrix production, may enhance the efficacy of MSCs in skin wound healing. This study aims to systematically evaluate the therapeutic efficacy of SPARC-overexpressing adipose-derived mesenchymal stem cells (ADSCs) in promoting skin wound healing by establishing wound models in normal, diabetic, and aged mice and dogs, thereby validating their potential under diverse physiological and pathological conditions. For in vitro validation, we used hydrogen peroxide (H2O2) to induce Human Umbilical Vein Endothelial Cell (HUVEC) and Human Keratinocyte Cell (HaCaT) injury. All animals were randomly assigned to six experimental groups as follows: (1) Model group: Untreated wound (negative control); (2) HY group: Hydrogel alone (vehicle control); (3) Con group: Control-ADSCs (cell control); (4) Con-Exo&HY group: Control-ADSC exosomes in hydrogel; (5) SPARC group: oe-SPARC-ADSCs (treatment); (6) SPARC-Exo&HY group: oe-SPARC-ADSC exosomes in hydrogel (treatment). Separately, HUVEC and HaCaT cells were assigned to four experimental conditions: a blank control group, a model group, a control-ADSC-treated group, and an oe-SPARC-ADSC-treated group. ADSCs modified by SPARC significantly promoted re-epithelialization integrity, collagen deposition, inflammation reduction, angiogenesis, and hair follicle regeneration during wound healing in dog skin. HUVEC and HaCaT cells proliferated after adding oe-SPARC-ADSCs cell supernatant. Meanwhile, quantitative proteomic sequencing data analysis showed that SPARC could promote skin wound healing by enhancing cell adhesion, hyaluronic acid binding, and vascular smooth muscle contraction of ADSCs. Both in vitro cellular assays and in vivo wound-healing models suggest that the combination of SPARC and ADSCs for the treatment of skin wounds has broad application prospects.

Diabetic foot ulcers are among the most common complications of diabetes and can lead to delayed wound healing. Fibroblast growth factor (FGF1) is a classic drug for the treatment of skin wounds but has the disadvantages of a short half-life and instability. Poly (lactic-co-glycolic acid) (PLGA) nanofibers are sustained-release biomaterials that have potential for use as therapeutic delivery systems. However, the therapeutic effect of PLGA loaded with recombinant human FGF1 (rhFGF1) on diabetic wound healing is unknown. Therefore, this study aimed to explore the therapeutic effects of PLGA-rhFGF1 in type 2 diabetic (T2D) wound mice. We found that PLGA offers good sustained release, which enhances the stability and bioactivity of rhFGF1. PLGA-rhFGF1 promoted wound closure, re-epithelialization and the expression of keratin 10 and keratin 14 in T2D mice on day 14. PLGA-rhFGF1 significantly decreased the levels of TNF-α and IL-6 in serum and skin tissues as well as the level of IL-1β in skin tissues. Moreover, PLGA-rhFGF1 decreased the mRNA levels of CXCL1, MCP1 and MIP2, and the fluorescence intensity of F4/80 and Ly6G in T2D wound mice and increased the collagen content and the protein expression of collagen I in the dermis of T2D wounds. PLGA-rhFGF1 also increased blood flow; the mRNA levels of the angiogenesis-related factors VEGF, Ang-1 and eNOS and the fluorescence intensity of CD31 in T2D wound mice. These data indicate that PLGA releases rhFGF1 slowly and promotes skin wound healing in T2D mice. The mechanisms through which PLGA-rhFGF1 produces these effects involve decreased inflammation and the promotion of granulation, re-epithelialization and angiogenesis.

Skin wound healing remains a major clinical challenge. Natural plant extracts have attracted increasing attention due to their high biocompatibility and biosafety, offering effective wound healing while avoiding antibiotic resistance and the development of resistant bacterial strains. Astragaloside IV (AS), a naturally active compound primarily extracted from Astragalus mongholicus Bunge, has demonstrated significant efficacy in promoting skin wound healing. AS is capable of modulating all phases of wound healing, including the inflammatory phase, proliferative phase, and remodeling phase. These effects contribute to reduced inflammation, accelerated tissue regeneration, and controlled scar formation by regulating immune responses and acting on various tissue cells. The potential of AS for clinical application in promoting skin wound healing has been confirmed by numerous invivo and in vitro studies; however, no comprehensive review has yet been published. This article provides the first systematic overview of the mechanisms by which AS and AS-loaded wound dressings promote wound healing, including the modulation of immune responses in wound healing through antimicrobial, antioxidative stress, and anti-inflammatory activities, and the regulation of endothelial cells, endothelial progenitor cells, fibroblasts, and keratinocytes to promote angiogenesis, collagen deposition, granulation tissue formation, and re-epithelialization. This article also summarizes the common types and advantages of AS-loaded wound dressings. These dressings enhance the bioavailability of AS and enable controlled release, while the incorporation of AS improves their physicochemical properties, thereby markedly enhancing therapeutic efficacy. Finally, the article points out existing research limitations, such as insufficient mechanistic exploration, a limited variety of AS-loaded dressing types, and the absence of clinical trials, and proposes future directions to advance the application.Impact StatementThe potential of AS for clinical application in promoting skin wound healing has been confirmed by numerous invivo and in vitro studies; however, no comprehensive review has yet been published. This article provides the first systematic overview of the mechanisms by which AS and AS-loaded wound dressings promote wound healing.

Skin wound healing remains a significant challenge in clinical medicine. Liposomes (LPs), as a versatile drug delivery system, have garnered widespread attention for their potential in promoting skin wound healing. However, the limitations of conventional LPs have hindered their broader clinical applications. To enhance the efficacy of LPs, researchers have developed various liposome-based delivery systems (LPs-DS) by integrating different materials and technologies. This review focuses on the field of skin wounds, highlighting the advantages of LPs-DS and clinical translational concepts in promoting skin wound healing. It summarizes their applications in different types of wounds and suggests potential future applications, aiming to provide a reference for further research on drug delivery systems.

Stapled peptide inhibitors target VGLL4/TEAD4 interactions to accelerate cutaneous wound healing.

Aloin enhances cutaneous wound healing in Labeo rohita by orchestrating antioxidant, cytokine and proliferative responses.

Scarless healing has always been the ultimate goal of surgery. Early intervention with a CO 2 ablative fractional laser (CO 2 AFL) has been found to improve the appearance of surgical scars. To investigate the mechanism of early intervention with a CO 2 AFL in promoting skin wound healing and the role of follicular stem cells. The authors used seven-week-old male LGR5-Cre, Rosa-mtmg (LGR5-mtmg), krt14-gfp-creer2, and BALBc mice to establish a skin incision model and apply CO 2 AFL treatment. The histological analysis and transcriptome sequencing were performed, and the results were verified using RT-PCR and western blotting. Transgenic fluorescent mice expressing Lgr5 and K14 were used to follow the trajectories of hair follicle stem cells and epidermal stem cells during wound healing. Histological analyses revealed that after CO 2 AFL treatment, the number of incision marks in the incision tissue was lower. After treatment, the number of Lgr6 and Lgr5+ hair follicle stem cells and K14 epidermal stem cells increased, and the expression of Trps1 and its downstream Wnt pathway increased. Early intervention with a CO 2 AFL to promote skin incision healing in mice may be achieved by activating Trps1 to regulate the Wnt/β-catenin pathway and promote hair follicle stem-cell participation in skin wound healing.

Targeting TWEAK/Fn14 pathway: Implications for stem cell regulation and advancements in skin disease therapies.

This study investigated the promotional effect of Hypericum aqueous extract on the healing of rabbit skin wounds and its possible mechanism. Sixteen New Zealand rabbits were modelled as skin defect trauma, and each rabbit had three wounds on the back skin, which were saline (Control), Hypericum aqueous extract (HAE), and Yunnan Baiyao (YNBY), and the wounds were cleaned and changed daily. The therapeutic effects were evaluated by wound gross observation, wound healing rate, and wound healing time, respectively, and we found that HAE could promote the wound healing rate. Histopathological staining observations showed that HAE improved the histologic changes of the wound and reduced the amount of inflammation. In addition, through the network pharmacology study, we obtained that the target of action was mainly focused on biological processes such as epithelial cell proliferation and signaling pathways such as PI3K-Akt, and the core targets included VEGFA, etc.; the validation results demonstrated that HAE significantly inhibited the expression of PI3K, P-PI3K, Akt and P-Akt, and it could increase the expression of VEGF, which helped to restore the vascularization of the wounds. In conclusion, Hypericum aqueous extract may promote wound healing by regulating the PI3K/Akt signaling pathway.

Bacterial and drug-resistant bacterial infections pose significant challenges to the treatment of skin wounds. Among various non-antibiotic strategies, nanozymes which mimic the activities of natural bioenzymes and possess broad-spectrum antibacterial properties, hold promise for antibacterial therapy in infected wounds. However, the catalytic activity and biosafety of most current nanozymes remain insufficient to meet clinical requirements. Herein, we innovatively synthesized novel heterostructured nanozymes (HNiZn) comprising Ni4N/Ni3ZnC0.7 embedded in accordion-shaped nitrogen-doped carbon using a simple molten-salt pyrolysis method. Combined with injectable hyaluronic acid (HA) as a carrier, these nanozymes facilitate low-temperature (43.5°C) photocatalytic and photothermal therapy for bacterially infected wounds. Based on density functional theory (DFT) calculations, the Ni4N/Ni3ZnC0.7 heterostructured nanozymes exhibit richer electron cloud distribution, stronger interactions between heterogeneous atoms, lower electron escape work function, stronger adsorption energy for free radicals, and electron transfer efficiency than individual Ni4N or Ni3ZnC0.7 phases, resulting in efficient peroxidase (POD)-like and glutathione peroxidase (GPx)-like activities. Additionally, HNiZn exhibits a high photothermal conversion efficiency (51.01%) under near infrared (NIR) irradiation. Through combined photocatalytic and photothermal effects, it effectively kills Escherichia coli (E. coli), clinically isolated methicillin-resistant Staphylococcus aureus (MRSA), and their biofilms. Mechanistic studies using metabolomics analysis revealed that HNiZn induces bacterial apoptosis by disrupting bacterial biosynthesis and metabolism, affecting the cell cycle, and perturbing redox balance. In vivo experiments further confirmed the favorable biosafety and antibacterial efficacy of HNiZn, which promoted skin wound healing. This study provides a novel strategy for constructing effective nanozymes and treating bacterial infections.

Effects of Agastache foeniculum essential oil on skin wound healing in mice.