Role of adipose‐derived stem cells in wound healing

Impaired wound healing remains a challenge to date and causes debilitating effects with tremendous suffering. Recent advances in tissue engineering approaches in the area of cell therapy have provided promising treatment options to meet the challenges of impaired skin wound healing such as diabetic foot ulcers. Over the last few years, stem cell therapy has emerged as a novel therapeutic approach for various diseases including wound repair and tissue regeneration. Several different types of stem cells have been studied in both preclinical and clinical settings such as bone marrow‐derived stem cells, adipose‐derived stem cells (ASCs), circulating angiogenic cells (e.g., endothelial progenitor cells), human dermal fibroblasts, and keratinocytes for wound healing. Adipose tissue is an abundant source of mesenchymal stem cells, which have shown an improved outcome in wound healing studies. ASCs are pluripotent stem cells with the ability to differentiate into different lineages and to secrete paracrine factors initiating tissue regeneration process. The abundant supply of fat tissue, ease of isolation, extensive proliferative capacities ex vivo, and their ability to secrete pro‐angiogenic growth factors make them an ideal cell type to use in therapies for the treatment of nonhealing wounds. In this review, we look at the pathogenesis of chronic wounds, role of stem cells in wound healing, and more specifically look at the role of ASCs, their mechanism of action and their safety profile in wound repair and tissue regeneration.     

羊膜负载骨髓间充质干细胞与表皮细胞对放创性皮肤损伤促愈合研究

目的探讨治疗放创性全厚皮肤缺损创面的方法及效果. 方法贵州小香猪8只,每只背部脊柱两侧均有放创性全层皮肤缺损圆形创面(Ф3.67cm)各3个,共48个创面.将经处理的人羊膜(human amniotic mambrane, HAM)分别负载自体骨髓间充质干细胞(mesenchymal stem cells, MSCs)和表皮细胞,移植到其左侧24个创面作为实验组(A组);以单纯无种植细胞的HAM敷盖其右侧前16个创面(B组);以单纯油纱布敷盖其右侧后8个创面(C组).B、C作为对照组.观察移植后1～3周内各组创面愈合、肉芽组织生长及上皮化等情况,并进行创面组织HE染色及vWF免疫组织化学检测.用图像分析法测算各组各时间点创面平均面积(cm2),并计算其愈合百分率. 结果 C组于伤后 22～23天愈合,B组于伤后19～21天愈合;A组于伤后15～17天愈合,较B、C组分别提前6～7天和5～6天,愈合质量好.移植15～17天,A组与B、C组创面平均残留面积及愈合面积百分率比较,差异有统计学意义(P＜0.01). A组创面的新生上皮已完全覆盖整个创面,肉芽组织生长旺盛,肉芽组织中vWF、成纤维细胞和毛细血管含量丰富,可见胶原沉积;B、C组创面仍见许多炎性细胞浸润,肉芽组织中vWF、成纤维细胞和毛细血管含量少,胶原沉积不明显. 结论 HAM负载自体MSCs和表皮细胞植入对放创性全厚皮肤缺损创面有较好的促愈合作用,愈合质量较高.     

静脉移植5-BrdU标记骨髓间充质干细胞参与创面愈合的作用研究

目的：探讨经尾静脉移植入体内的骨髓间充质干细胞（BMSCs）参与皮肤创面愈合的情况。方法：以SD大鼠为研究对象，分离、培养并鉴定大鼠BMSCs。制作大鼠全层皮肤缺损动物模型；经尾静脉注入经5-BrdU标记的骨髓间充质干细胞，于不同时间点（3、7、14、21、28天）观察移植细胞参与创面愈合的情况。结果：经流式细胞仪鉴定细胞表达CD29、CD90表达阳性；CD45表达呈阴性：经体外标记的5-溴脱氧尿嘧啶标记率〉90％；标记后的干细胞进行移植4周后，实验组大鼠创面局部及边缘可见BrdU标记的阳性细胞聚集，对照组中未发现明显的聚集现象。结论：5-BrdU完全能够满足移植细胞的标记需要。经尾静脉注射移植入体内的BMSCs可能参与皮肤创面愈合。     

Extracorporeal shock wave therapy (ESWT) for wound healing: Technology,mechanisms, and clinical efficacy

For almost 30 years, extracorporeal shock wave therapy has been clinically implemented as an effective treatment to disintegrate urinary stones. This technology has also emerged as an effective noninvasive treatment modality for several orthopedic and traumatic indications including problematic soft tissue wounds. Delayed/nonhealing or chronic wounds constitute a burden for each patient affected, significantly impairing quality of life. Intensive wound care is required, and this places an enormous burden on society in terms of lost productivity and healthcare costs. Therefore, cost‐effective, noninvasive, and efficacious treatments are imperative to achieve both (accelerated and complete) healing of problematic wounds and reduce treatment‐related costs. Several experimental and clinical studies show efficacy for extracorporeal shock wave therapy as means to accelerate tissue repair and regeneration in various wounds. However, the biomolecular mechanism by which this treatment modality exerts its therapeutic effects remains unclear. Potential mechanisms, which are discussed herein, include initial neovascularization with ensuing durable and functional angiogenesis. Furthermore, recruitment of mesenchymal stem cells, stimulated cell proliferation and differentiation, and anti‐inflammatory and antimicrobial effects as well as suppression of nociception are considered important facets of the biological responses to therapeutic shock waves. This review aims to provide an overview of shock wave therapy, its history and development as well as its current place in clinical practice. Recent research advances are discussed emphasizing the role of extracorporeal shock wave therapy in soft tissue wound healing.     

Treatment with bone marrow-derived stromal cells accelerates wound healing in diabetic rats

Bone marrow stem cells participate in tissue repair processes and may have a role in wound healing. Diabetes is characterised by delayed and poor wound healing. We investigated the potential of bone marrow-derived mesenchymal stromal cells (BMSCs) to promote healing of fascial wounds in diabetic rats. After manifestation of streptozotocin (STZ)-induced diabetic state for 5 weeks in male adult Sprague-Dawley rats, healing of fascial wounds was severely compromised. Compromised wound healing in diabetic rats was characterised by excessive polymorphonuclear cell infiltration, lack of granulation tissue formation, deficit of collagen and growth factor [transforming growth factor (TGF-beta), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), platelet-derived growth factor PDGF-BB and keratinocyte growth factor (KGF)] expression in the wound tissue and significant decrease in biomechanical strength of wounds. Treatment with BMSC systemically or locally at the wound site improved the wound-breaking strength (WBS) of fascial wounds. The improvement in WBS was associated with an immediate and significant increase in collagen levels (types I-V) in the wound bed. In addition, treatment with BMSCs increased the expression of growth factors critical to proper repair and regeneration of the damaged tissue moderately (TGF-beta, KGF) to markedly (EGF, VEGF, PDGF-BB). These data suggest that cell therapy with BMSCs has the potential to augment healing of the diabetic wounds.     

Adipose-derived stem cells for wound healing applications

Nonhealing wounds remain a significant challenge for plastic surgeons. More than 600,000 people suffer from venous ulcers and 1.5 to 3 million people are being treated for pressure sores every year in the United States. The use of tissue engineering techniques such as stem-cell therapy and gene therapy to improve wound healing is a promising strategy. Adipose tissue represents a source of cells that may be able to enhance wound healing. Adipose-derived stem cells (ASCs) are adult stem cells that are easily harvested and of great interest for plastic surgeons. Specifically, ASCs secrete angiogenic growth factors that can induce tissue regeneration. This review describes innovative research strategies using ASCs therapies for treatment of chronic, nonhealing wounds.     

Microdeformation in wound healing

Mechanical forces greatly influence cellular organization and behavior. Cells respond to applied stress by changes in form and composition until a suitable state is reestablished. However, without any mechanical stimuli cells stop proliferating, discontinue migration, go into cell‐cycle arrest, and eventually die. Hence, one can assume that pathologies closely depending on cell migration like cancer or atherosclerosis might be governed by biophysical parameters. Moreover, mechanical cues will have fundamental effects in wound healing. Especially negative pressure wound therapy has the potential to endorse wound healing by induction of both macrodeformation (wound contraction) and microdeformation (tissue reactions at microscopic level). So far, the capacity for researchers to study the link between mechanical stimulation and biological response has been limited by the lack of instrumentation capable of stimulating the tissue in an appropriate manner. However, first reports on application of micromechanical forces to wounds elucidate the roles of cell stretch, substrate stiffness, and tissue deformation during cell proliferation and differentiation. This review deals with their findings and tries to establish a link between the current knowledge and the questions that are essential to clinicians in the field: What is the significance of mirodeformations for wound healing? Does “dead space” impede propagation of mechanical cues? How can microdeformations induce cell proliferation? What role do fibroblasts, myofibroblasts, and mesenchymal stem cells play in chronic wounds with regard to micromechanical forces?     

Tissue‐Engineered Skin Containing Mesenchymal Stem Cells Improves Burn Wounds

There is increasing evidence showing that adult stem cells are useful for tissue regeneration. Bone marrow mesenchymal stem cells (MSCs) are self‐renewing and are potent in differentiating into multiple cells and tissues. To investigate the practicability of repairing burn wounds with tissue‐engineered (TE) skin combined with bone MSCs, we established a burn wound model in the porcine skin. With a controlling temperature and time of the burning device to obtain different degrees of burn wounds, a deep dermal partial thickness burn was introduced to the porcine skin using a heated‐brass contact injury at 100°C for 20 s. Collagen‐GAG scaffolds were utilized as the matrix; MSCs separated from pigs were seeded on them to form the skin equivalent. When grafted to the burn wounds, the TE skin containing MSCs showed better healing and keratinization, less wound contraction, and more vascularization. Grafts proliferated well and contributed to the neo‐tissues. These data suggest that TE skin containing MSCs in a burn defect can accelerate wound healing and receive satisfactory effects.     

An update review of stem cell applications in burns and wound care

The ultimate goal of the treatment of cutaneous burns and wounds is to restore the damaged skin both structurally and functionally to its original state. Recent research advances have shown the great potential of stem cells in improving the rate and quality of wound healing and regenerating the skin and its appendages. Stem cell-based therapeutic strategies offer new prospects in the medical technology for burns and wounds care. This review seeks to give an updated overview of the applications of stem cell therapy in burns and wound management since our previous review of the “stem cell strategies in burns care”.KEY WORDS: Burns, stem cell, wound     

The role of microRNA‐15b in the impaired angiogenesis in diabetic wounds

The impairment in diabetic wound healing represents a significant clinical problem. Decreased angiogenesis is thought to play a central role in the pathogenesis of this impairment. We have previously shown that treatment of diabetic murine wounds with mesenchymal stem cells can improve healing, but the mechanisms are not completely defined. MicroRNA‐15b (miR‐15b) has been implicated in the regulation of the angiogenic response. We hypothesized that abnormal miR‐15b expression may contribute to the impaired angiogenesis observed in impaired diabetic wound healing. To test this hypothesis, we examined the expression of miR‐15b and its target genes in diabetic and nondiabetic mice before and after injury. MiR‐15b expression was significantly up‐regulated in diabetic mouse wounds during the wound healing response. Increased miR‐15b levels also closely correlated with decreased gene expression of its proangiogenic target genes. Furthermore, the correction of the diabetic wound healing impairment with mesenchymal stem cell treatment was associated with a significant decrease in miR‐15b expression level and increased gene expression of its proangiogenic target genes. These results provide the first evidence that increased expression of miR‐15b in diabetic wounds in response to injury may, in part, be responsible for the abnormal angiogenic response seen in diabetic wounds and may contribute to the observed wound healing impairment.     

Bone marrow-derived mesenchymal stromal cells accelerate wound healing in the rat

Bone marrow-derived mesenchymal stromal cells (BMSCs) are multipotential stem cells capable of differentiation into numerous cell types, including fibroblasts, cartilage, bone, muscle, and brain cells. BMSCs also secrete a large number of growth factors and cytokines that are critical to the repair of injured tissues. Because of the extraordinary plasticity and the ability of syngeneic or allogeneic BMSCs to secrete tissue-repair factors, we investigated the therapeutic efficacy of BMSCs for healing of fascial and cutaneous incisional wounds in Sprague-Dawley rats. Systemic administration of syngeneic BMSCs (2 x 10(6)) once daily for 4 days or a single treatment with 5 x 10(6) BMSCs 24 hours after wounding significantly increased the wound bursting strength of fascial and cutaneous wounds on days 7 and 14 postwounding. Wound healing was also significantly improved following injection of BMSCs locally at the wound site. Furthermore, allogeneic BMSCs were as efficient as syngeneic BMSCs in promoting wound healing. Administration of BMSCs labeled with iron oxides/1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate fluorescent dye revealed that systemically administered BMSCs engraft to the wound. The increase in the tensile strength of wounds treated with BMSCs was associated with increased production of collagen in the wound. In addition, BMSC treatment caused more rapid histologic maturation of wounds compared with untreated wounds. These data suggest that cell therapy with BMSCs has the potential to augment healing of surgical and cutaneous wounds.     

Application of stems cells in wound healing—An update

Wound healing is a complex but well‐orchestrated tissue repair process composed of a series of molecular and cellular events conducted by various types of cells and extracellular matrix. Despite a variety of therapeutic strategies proposed to accelerate the healing of acute and/or chronic wounds over the past few decades, effective treatment of chronic nonhealing wounds still remains a challenge. Due to the recent advances in stem cell research, a dramatic enthusiasm has been drawn to the application of stem cells in regenerative medicine. Both embryonic and adult stem cells have prolonged self‐renewal capacity and are able to differentiate into various tissue types. Nevertheless, use of embryonic stem cells is limited, owing to ethical concerns and legal restrictions. Adult stem cells, which could be isolated from bone marrow, umbilical cord blood, adipose tissue, skin and hair follicles,are being explored extensively to facilitate the healing of both acute and chronic wounds. The current article summarizes recent research on various types of stem cell‐based strategies applied to improve wound healing. In addition, future directions of stem cell‐based therapy in wound healing have also been discussed. Finally, despite its apparent advantages, limitations and challenges of stem cell therapy are discussed.     

Embryonic stem cell–derived M2‐like macrophages delay cutaneous wound healing

In adults, repair of deeply injured skin wounds results in the formation of scar tissue, whereas in embryos wounds heal almost scar‐free. Macrophages are important mediators of wound healing and secrete cytokines and tissue remodeling enzymes. In contrast to host defense mediated by inflammatory M1 macrophages, wound healing and tissue repair involve regulatory M2/M2‐like macrophages. Embryonic/fetal macrophages are M2‐like, and this may promote scar‐free wound healing. In the present study, we asked whether atopical application of ex vivo generated, embryonic stem cell–derived macrophages (ESDM) improve wound healing in mice. ESDM were tested side by side with bone marrow–derived macrophages (BMDM). Compared to BMDM, ESDM resembled a less inflammatory and more M2‐like macrophage subtype as indicated by their reduced responsiveness to lipopolysaccharide, reduced expression of Toll‐like receptors, and reduced bacterial phagocytosis. Despite this anti‐inflammatory phenotype in cell culture, ESDM prolonged the healing of deep skin wounds even more than BMDM. Healed wounds had more scar formation compared to wounds receiving BMDM or cell‐free treatment. Our data indicate that atopical application of ex vivo generated macrophages is not a suitable cell therapy of dermal wounds.     

Stem cells in burn eschar

This study compares mesenchymal cells isolated from excised burn wound eschar with adipose-derived stem cells (ASCs) and dermal fibroblasts in their ability to conform to the requirements for multipotent mesenchymal stem cells (MSCs). A population of multipotent stem cells in burn eschar could be an interesting resource for tissue engineering approaches to heal burn wounds. Cells from burn eschar, dermis, and adipose tissue were assessed for relevant CD marker profiles using flow cytometry and for their trilineage differentiation ability in adipogenic, osteogenic, and chondrogenic conditions. Although the different cell types did not differ significantly in their CD marker expression, the eschar-derived cells and ASCs readily differentiated into adipocytes, osteoblasts, and chondrocytes, while dermal fibroblasts only exhibited some chondrogenic potential. We conclude that the eschar-derived mesenchymal cells represent a population of multipotent stem cells. The origin of the cells from burn eschar remains unclear, but it is likely they represent a population of adult stem cells mobilized from other parts of the body in response to the burn injury. Their resemblance to ASCs could also be cause for speculation that in deep burns the subcutaneous adipose tissue might be an important stem cell source for the healing wound.     

Cellular events and biomarkers of wound healing

Researchers have identified several of the cellular events associated with wound healing. Platelets, neutrophils, macrophages, and fibroblasts primarily contribute to the process. They release cytokines including interleukins (ILs) and TNF-α, and growth factors, of which platelet-derived growth factor (PDGF) is perhaps the most important. The cytokines and growth factors manipulate the inflammatory phase of healing. Cytokines are chemotactic for white cells and fibroblasts, while the growth factors initiate fibroblast and keratinocyte proliferation. Inflammation is followed by the proliferation of fibroblasts, which lay down the extracellular matrix. Simultaneously, various white cells and other connective tissue cells release both the matrix metalloproteinases (MMPs) and the tissue inhibitors of these metalloproteinases (TIMPs). MMPs remove damaged structural proteins such as collagen, while the fibroblasts lay down fresh extracellular matrix proteins. Fluid collected from acute, healing wounds contains growth factors, and stimulates fibroblast proliferation, but fluid collected from chronic, nonhealing wounds does not. Fibroblasts from chronic wounds do not respond to chronic wound fluid, probably because the fibroblasts of these wounds have lost the receptors that respond to cytokines and growth factors. Nonhealing wounds contain high levels of IL1, IL6, and MMPs, and an abnormally high MMP/TIMP ratio. Clinical examination of wounds inconsistently predicts which wounds will heal when procedures like secondary closure are planned. Surgeons therefore hope that these chemicals can be used as biomarkers of wounds which have impaired ability to heal. There is also evidence that the application of growth factors like PDGF will help the healing of chronic, nonhealing wounds.KEY WORDS: Cytokines, growth factors, matrix metalloproteinases, platelet-derived growth factor, wound healingIn the last 30 or so years, researchers have identified several of the cellular and biochemical events associated with wound healing. The process is becoming clearer, with the understanding of the cells and chemicals that help wounds to heal, and of those that inhibit healing. Investigators are trying to analyze the chemicals in chronic wounds in order to determine their condition and fitness for closure. A major advance is the clinical application of some of these chemicals to improve outcomes in wound healing.In this paper we look at the biology of normal and abnormal healing, see if wounds analysis can predict poor healing, and review some literature on the clinical applications of this knowledge.     

Muscle-derived stem cells used to treat skin defects prevent wound contraction and expedite reepithelialization

Stem cells derived from adult tissues may serve as cell therapy to enhance the healing process in skin wounds. This study was designed to evaluate the use of autologous muscle-derived stem cells in an experimental skin wound model in terms of their efficiency at promoting tissue repair/regeneration. Muscle-derived cells obtained from the dorsal muscle of New Zealand rabbits were cultured in vitro for 2 weeks. The cell population was identified using the satellite markers CD34, m-cadherin and Myf5, and the proliferative capacity of the adult stem cells was determined. The population was then fluorescently labeled with PKH26 and seeded onto a circular 2 cm diameter defect created on the dorsal side of the ear of the rabbit from which the cells had been harvested. Similar defects on the contra lateral ears were left untreated to form the control group. Fourteen days later, specimens were taken for light, transmission, and scanning electron microscopy, as well as for immunolabeling with antibodies against vimentin, alpha-actin, desmin, myosin, fibronectin, and cytokeratin 14. Areas of wound contraction and reepithelialization were determined by image analysis. Wound contraction was significantly greater in the control than the treatment group (p<0.05); control specimens also showed more myosin expression. Reepithelialized areas were significantly greater in the treatment group (p<0.05). Control wounds showed nonepithelialized areas and inflammatory granulation tissue. Reepithelialization occurred as epidermal tongues of fusiform cells. Our findings indicate that the use of autologous stem cells on skin wounds expedites and improves the organism's natural healing process.     

A review of gene and stem cell therapy in cutaneous wound healing

Different therapies that effect wound repair have been proposed over the last few decades. This article reviews the emerging fields of gene and stem cell therapy in wound healing. Gene therapy, initially developed for treatment of congenital defects, is a new option for enhancing wound repair. In order to accelerate wound closure, genes encoding for growth factors or cytokines showed the greatest potential. The majority of gene delivery systems are based on viral transfection, naked DNA application, high pressure injection, or liposomal vectors. Embryonic and adult stem cells have a prolonged self-renewal capacity with the ability to differentiate into various tissue types. A variety of sources, such as bone marrow, peripheral blood, umbilical cord blood, adipose tissue, skin and hair follicles, have been utilized to isolate stem cells to accelerate the healing response of acute and chronic wounds. Recently, the combination of gene and stem cell therapy has emerged as a promising approach for treatment of chronic and acute wounds.     

SCF increases in utero–labeled stem cells migration and improves wound healing

Diabetic skin wounds lack the ability to heal properly and constitute a major and significant complication of diabetes. Nontraumatic lower extremity amputations are the number one complication of diabetic skin wounds. The complexity of their pathophysiology requires an intervention at many levels to enhance healing and wound closure. Stem cells are a promising treatment for diabetic skin wounds as they have the ability to correct abnormal healing. Stem cell factor (SCF), a chemokine expressed in the skin, can induce stem cells migration, however the role of SCF in diabetic skin wound healing is still unknown. We hypothesize that SCF would correct the impairment and promote the healing of diabetic skin wounds. Our results show that SCF improved wound closure in diabetic mice and increased HIF‐1α and vascular endothelial growth factor (VEGF) expression levels in these wounds. SCF treatment also enhanced the migration of red fluorescent protein (RFP)‐labeled skin stem cells via in utero intra‐amniotic injection of lenti‐RFP at E8. Interestingly these RFP+ cells are present in the epidermis, stain negative for K15, and appear to be distinct from the already known hair follicle stem cells. These results demonstrate that SCF improves diabetic wound healing in part by increasing the recruitment of a unique stem cell population present in the skin.     

LPS-pretreatment adipose-derived mesenchymal stromal cells promote wound healing in diabetic rats by improving angiogenesis

Mesenchymal stem cells (MSCs) play a key role in wound healing, and the advantages of pretreated MSCs in wound healing have previously been reported. In the present study, we investigated the impact of LPS pretreated human adipose-derived MSCs on skin wound healing in diabetic rats. We found that some improvements occurred through improving angiogenesis. Then, we scrutinized the impact of lipopolysaccharide (LPS) treatment on human adipose-derived MSCs in a high-glucose (HG) medium, as an in vitro diabetic model. In vivo findings revealed significant improvements in epithelialization and angiogenesis of diabetic wounds which received LPS pre-MSCs. Particularly, LPS pre-MSCs-treated diabetic wounds reached considerably higher percentages of wound closure. Also, the granulation tissue of these wounds had higher pronounced epithelialization and more vascularization compared with PBS-treated and MSCs-treated diabetic ones by CD31, VEGF, CD90, collagen 1, and collagen 3 immunostaining. Western-blots analyses indicated that LPS pre-MSCs led to the upregulation of vascular endothelial growth factor (VEGF) and DNMT1. In addition, significantly higher cell viability (proliferation/colonie), and elevated VEGF and DNMT1 protein expression were observed when MSCs were treated with LPS (10 ng/ml, 6 h) in HG culture media. Based on these findings, it is suggested that LPS pre-MSCs could promote wound repair and skin regeneration, in some major processes, via the improvement of cellular behaviors of MSCs in the diabetic microenvironment. The beneficial advantages of LPS treated with mesenchymal stem cells on wound healing may lead to establishing a novel approach as an alternative therapeutic procedure to cure chronic wounds in diabetic conditions.     

Transplantation of BMSCs expressing hVEGF165/hBD3 promotes wound healing in rats with combined radiation‐wound injury

The combined radiation‐wound injury is a refractory wound with decreased number or dysfunction of repairing cells and growth factors. This remains a challenge in clinical practice. The object of this study is to evaluate the therapeutic efficacy of a combination of human vascular endothelial growth factor 165 (hVEGF₁₆₅) and human beta‐defensin 3 (hBD3) in the treatment of such wounds. A plasmid‐carrying hVEGF₁₆₅ gene and hBD3 gene was used to transfect rat bone‐marrow‐derived mesenchymal stem cells (BMSCs). The supernatant from the modified BMSCs significantly promoted the proliferation and cell migration of human endothelial cells and it also inhibited the growth of bacteria and fungus, demonstrating the successful expression of the transfected genes. The hVEGF₁₆₅/hBD3‐modified BMSCs were then injected into the sites of combined radiation‐wound injury on rats. It demonstrated that wound‐healing time was shortened significantly in the treated rats. The granulation tissue formation/maturation, skin appendage regeneration and collagen deposition were also improved significantly. Strong expression of hVEGF₁₆₅ and hBD3 was detected in the wound surface at early stage of the healing. The results indicate that topical transplantation of hVEGF₁₆₅/hBD3‐modified BMSCs promoted wound healing, and this gene therapy strategy presents a promising approach in the treatment of refractory wounds such as the combined radiation‐wound injury.