Effects of Human Cord Blood Mesenchymal Stem Cells on Cutaneous Wound Healing in Lepr db Mice

Stem Cell-Mediated Angiogenesis in Skin Tissue Engineering and Wound Healing

The timely management of skin wounds has been an unmet clinical need for centuries. While there have been several attempts to accelerate wound healing and reduce the cost of hospitalisation and the healthcare burden, there remains a lack of efficient and effective wound healing approaches. In this regard, stem cell‐based therapies have garnered an outstanding position for the treatment of both acute and chronic skin wounds. Stem cells of different origins (e.g., embryo‐derived stem cells) have been utilised for managing cutaneous lesions; specifically, mesenchymal stem cells (MSCs) isolated from foetal (umbilical cord) and adult (bone marrow) tissues paved the way to more satisfactory outcomes. Since angiogenesis plays a critical role in all four stages of normal wound healing, recent therapeutic approaches have focused on utilising stem cells for inducing neovascularisation. In fact, stem cells can promote angiogenesis via either differentiation into endothelial lineages or secreting pro‐angiogenic exosomes. Furthermore, particular conditions (e.g., hypoxic environments) can be applied in order to boost the pro‐angiogenic capability of stem cells before transplantation. For tissue engineering and regenerative medicine applications, stem cells can be combined with specific types of pro‐angiogenic biocompatible materials (e.g., bioactive glasses) to enhance the neovascularisation process and subsequently accelerate wound healing. As such, this review article summarises such efforts emphasising the bright future that is conceivable when using pro‐angiogenic stem cells for treating acute and chronic skin wounds.

E-Selectin-Overexpressing Mesenchymal Stem Cell Therapy Confers Improved Reperfusion, Repair, and Regeneration in a Murine Critical Limb Ischemia Model

AIMS

Novel cell-based therapeutic angiogenic treatments for patients with critical limb ischemia may afford limb salvage. Mesenchymal stem cells (MSCs) do not overexpress E-selectin; however, we have previously demonstrated the cell-adhesion molecule's vital role in angiogenesis and wound healing. Thus, we created a viral vector to overexpress E-selectin on MSCs to increase their therapeutic profile.

METHODS AND RESULTS

Femoral artery ligation induced hind limb ischemia in mice and intramuscular injections were administered of vehicle or syngeneic donor MSCs, transduced ex vivo with an adeno-associated viral vector to express either GFP+ (MSCGFP) or E-selectin-GFP+ (MSCE-selectin-GFP). Laser Doppler Imaging demonstrated significantly restored reperfusion in MSCE-selectin-GFP-treated mice vs. controls. After 3 weeks, the ischemic limbs in mice treated with MSCE-selectin-GFP had increased footpad blood vessel density, hematoxylin and eosin stain (H&E) ischemic calf muscle sections revealed mitigated muscular atrophy with restored muscle fiber size, and mice were able to run further before exhaustion. PCR array-based gene profiling analysis identified nine upregulated pro-angiogenic/pro-repair genes and downregulated Tumor necrosis factor (TNF) gene in MSCE-selectin-GFP-treated limb tissues, indicating that the therapeutic effect is likely achieved via upregulation of pro-angiogenic cytokines and downregulation of inflammation.

CONCLUSION

This innovative cell therapy confers increased limb reperfusion, neovascularization, improved functional recovery, decreased muscle atrophy, and thus offers a potential therapeutic method for future clinical studies.

Systemic Fibrocyte Levels and Keloid Expression of the Chemoattractant CXCL12 Are Upregulated Compared With Patients With Normal Scar

BACKGROUND

Fibrocytes are bone marrow mesenchymal precursors with a surface phenotype compatible with leukocytes, fibroblasts, and hematopoietic progenitors that have been shown to traffic to wound healing sites in response to described chemokine pathways. Keloids are focal fibrotic responses to cutaneous trauma characterized by disordered collagen, which may be associated with elevated systemic fibrocyte levels and/or wound bed chemokine expression.

METHODS

Blood specimens from patients with longstanding keloids and those who form grossly normal scars were assayed by fluorescence activated cell sorting analysis for fibrocytes (CD45+, Col I+). The expression of the fibrocyte chemotactic cell surface marker CXCR4, intracellular markers of fibroblast differentiation (pSMAD2/3), and plasma levels of the CXCR4 cognate CXCL12 were compared. Keloid specimens and grossly normal scars were excised, and local expression of CXCL12 was assayed.

RESULTS

Keloid-forming patients demonstrated a significantly greater number of circulating fibrocytes (17.4 × 105 cells/mL) than control patients (1.01 × 105 cells/mL, P = 0.004). The absolute number of fibrocytes expressing CXCR4 was significantly greater (P = 0.012) in keloid-forming patients. Systemic CXCL12 levels were insignificantly greater in keloid-forming patients than controls. Keloid specimens had significantly greater CXCL12 expression (529.3 pg/mL) than normal scar (undetectable).

CONCLUSIONS

Systemic fibrocyte levels and the CXCR4/CXCL12 biologic axis responsible for fibrocyte trafficking to areas of regional fibrosis were both upregulated in patients who form keloids compared with controls. Keloids persistently expressed CXLC12, which serves both as the main chemoattractant for fibrocytes and a downstream mediator for local inflammation, suggesting a role for this biologic axis in keloid formation and possibly recurrence.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Proficiency of Carboxymethylcellulose as a Cryoprotectant. Clinical and Histological Evaluation of Cryopreserved Heterogenous Mesenchymal Stem Cell-Exosomal Hydrogel on Critical Size Skin Wounds in Dogs

Background: Fresh stem cell exosomes are usually obtained and reused in the same individual. It cannot be kept viable for a long period of time regardless of the lengthy preparation time. Freezing is typically used to preserve the viability of perishable materials and increase their lifetime. Regrettably, normal freezing of biomaterials leads to cell damage. Therefore, a cryoprotectant can save the cells from the conventional cryodamage. Sodium carboxymethylcellulose (NA-CMC) is a powdery substance that is used to manufacture bio-safe hydrofilm gels because of its high viscosity, cytocompatibility, and nonallergenic nature.

Materials and Methods: Sterile CMC hydrogel was prepared, part of which was loaded with exosomal solution derived from MSCs. The gel was kept at −20°C for preservation. Two bilateral full-thickness circular skin wounds of 2-cm diameter were created on the back of experimental dogs. The wounds were at least 2.5 cm apart. Treatment started 24 hours after wound creation. Group I received CMC gel solely, whereas group II received frozen CMC exosomal gel. The gel was applied 4 times, a single application per day with 1- day interval.

Results: Clinically, the frozen exosomal gel significantly promoted wound healing with no scaring. Histologically, enhanced dermal fibroblasts and organized collagen deposition were seen in the treated group.

Conclusion: CMC proved to be an efficient cryoprotectant and a suitable vehicle for exosomes. Deep freezing was proven to conserve the viability, extended the preservation, and facilitated the usage of exosomal gel. This technique of preserved cell-free therapy is inexpensive, time-saving, and proficient and seems suitable for treating cutaneous wounds.

Acellular and cellular approaches to improve diabetic wound healing

Chronic diabetic wounds represent a huge socioeconomic burden for both affected individuals and the entire healthcare system. Although the number of available treatment options as well as our understanding of wound healing mechanisms associated with diabetes has vastly improved over the past decades, there still remains a great need for additional therapeutic options. Tissue engineering and regenerative medicine approaches provide great advantages over conventional treatment options, which are mainly aimed at wound closure rather than addressing the underlying pathophysiology of diabetic wounds. Recent advances in biomaterials and stem cell research presented in this review provide novel ways to tackle different molecular and cellular culprits responsible for chronic and nonhealing wounds by delivering therapeutic agents in direct or indirect ways. Careful integration of different approaches presented in the current article could lead to the development of new therapeutic platforms that can address multiple pathophysiologic abnormalities and facilitate wound healing in patients with diabetes.

Stem cell therapy for diabetic foot ulcers: a review of preclinical and clinical research

BACKGROUND

Diabetic foot ulcer (DFU) is a severe complication of diabetes, preceding most diabetes-related amputations. DFUs require over US$9 billion for yearly treatment and are now a global public health issue. DFU occurs in the setting of ischemia, infection, neuropathy, and metabolic disorders that result in poor wound healing and poor treatment options. Recently, stem cell therapy has emerged as a new interventional strategy to treat DFU and appears to be safe and effective in both preclinical and clinical trials. However, variability in the stem cell type and origin, route and protocol for administration, and concomitant use of angioplasty confound easy interpretation and generalization of the results.

METHODS

The PubMed, Google Scholar, and EMBASE databases were searched and 89 preclinical and clinical studies were selected for analysis.

RESULTS

There was divergence between preclinical and clinical studies regarding stem cell type, origin, and delivery techniques. There was heterogeneous preclinical and clinical study design and few randomized clinical trials. Granulocyte-colony stimulating factor was employed in some studies but with differing protocols. Concomitant performance of angioplasty with stem cell therapy showed increased efficiency compared to either therapy alone.

CONCLUSIONS

Stem cell therapy is an effective treatment for diabetic foot ulcers and is currently used as an alternative to amputation for some patients without other options for revascularization. Concordance between preclinical and clinical studies may help design future randomized clinical trials.

Histological Evaluation of Experimentally Induced Critical Size Defect Skin Wounds Using Exosomal Solution of Mesenchymal Stem Cells Derived Microvesicles

Background and Objectives

The present study investigated whether MSCs derived microvesicles (MVs) or (Exosomes) can exert therapeutic effects on an experimental model of cutaneous injury and explored the underlying involving mechanisms.

Methods and Results

Three bilateral full thickness circular wounds were created on the back of two groups of dogs using 2-cm dermal punch. The wounds were at least 2.5 cm apart. Saline was subcutaneously injected in 4 places around each wound area in group-I (control), whereas an equal volume of exosomal solution of MSCs derived MVs was similarly injected in group-II. The findings demonstrated that MSCs derived MVs had significantly promoted cutaneous wound healing, collagen synthesis, and vascularization at wound sites. The application of the exosomal solution had not only promoted the generation of newly formed vessels, but also have accelerated their development and maturation leading to a faster healing process.

Conclusions

MSC-Exosomes appeared to be a superior candidate for treating cutaneous wounds than their originator cells, and may represent a promising opportunity to develop a novel cell-free therapy approach that might overcome the obstacles and risks associated with the use of native or engineered stem cells transplantation therapy.

Comparison of human umbilical cord blood-derived mesenchymal stem cells with healthy fibroblasts on wound-healing activity of diabetic fibroblasts

Various types of skin substitutes composed of fibroblasts and/or keratinocytes have been used for the treatment of diabetic ulcers. However, the effects have generally not been very dramatic. Recently, human umbilical cord blood-derived mesenchymal stromal cells (hUCB-MSCs) have been commercialised for cartilage repair as a first cell therapy product using allogeneic stem cells. In a previous pilot study, we reported that hUCB-MSCs have a superior wound-healing capability compared with fibroblasts. The present study was designed to compare the treatment effect of hUCB-MSCs with that of fibroblasts on the diabetic wound healing in vitro. Diabetic fibroblasts were cocultured with healthy fibroblasts or hUCB-MSCs. Five groups were evaluated: group I, diabetic fibroblasts without coculture; groups II and III, diabetic fibroblasts cocultured with healthy fibroblasts or hUCB-MSCs; and groups IV and V, no cell cocultured with healthy fibroblasts or hUCB-MSCs. After a 3-day incubation, cell proliferation, collagen synthesis levels and glycosaminoglycan levels, which are the major contributing factors in wound healing, were measured. As a result, a hUCB-MSC-treated group showed higher cell proliferation, collagen synthesis and glycosaminoglycan level than a fibroblast-treated group. In particular, there were significant statistical differences in collagen synthesis and glycosaminoglycan levels (P = 0·029 and P = 0·019, respectively). In conclusion, these results demonstrate that hUCB-MSCs may have a superior effect to fibroblasts in stimulating diabetic wound healing.

Immune Tolerance of Human Dental Pulp-Derived Mesenchymal Stem Cells Mediated by CD4⁺CD25⁺FoxP3⁺ Regulatory T-Cells and Induced by TGF-β1 and IL-10

PURPOSE

Most studies on immune tolerance of mesenchymal stem cells (MSCs) have been performed using MSCs derived from bone marrow, cord blood, or adipose tissue. MSCs also exist in the craniofacial area, specifically in teeth. The purpose of this study was to evaluate the mechanisms of immune tolerance of dental pulp-derived MSC (DP-MSC) in vitro and in vivo.

MATERIALS AND METHODS

We isolated DP-MSCs from human dental pulp and co-cultured them with CD4⁺ T-cells. To evaluate the role of cytokines, we blocked TGF-β and IL-10, separately and together, in co-cultured DP-MSCs and CD4⁺ T-cells. We analyzed CD25 and FoxP3 to identify regulatory T-cells (Tregs) by fluorescence-activated cell sorting (FACS) and real-time PCR. We performed alloskin grafts with and without DP-MSC injection in mice. We performed mixed lymphocyte reactions (MLRs) to check immune tolerance.

RESULTS

Co-culture of CD4⁺ T-cells with DP-MSCs increased the number of CD4⁺CD25⁺FoxP3⁺ Tregs (p<0.01). TGF-β or/and IL-10 blocking suppressed Treg induction in co-cultured cells (p<0.05). TGF-β1 mRNA levels were higher in co-cultured DP-MSCs and in co-cultured CD4⁺ T-cells than in the respective monocultured cells. However, IL-10 mRNA levels were not different. There was no difference in alloskin graft survival rate and area between the DP-MSC injection group and the non-injection group. Nonetheless, MLR was reduced in the DP-MSC injected group (p<0.05).

CONCLUSION

DP-MSCs can modulate immune tolerance by increasing CD4⁺CD25⁺FoxP3⁺ Tregs. TGF-β1 and IL-10 are factors in the immune-tolerance mechanism. Pure DP-MSC therapy may not be an effective treatment for rejection, although it may module immune tolerance in vivo.

Effects of human umbilical cord blood-derived mesenchymal stromal cells and dermal fibroblasts on diabetic wound healing

BACKGROUND AIMS

A previous study demonstrated that human umbilical cord blood-derived mesenchymal stromal cells (hUCB-MSCs) have superior wound-healing activity compared with fibroblasts in vitro. However, wound healing in vivo is a complex process that involves multiple factors. The purpose of this study was to compare the effects of hUCB-MSCs and fibroblasts on diabetic wound healing in vivo. This study especially focused on collagen synthesis and angiogenesis, which are considered to be the important factors affecting diabetic wound healing.

METHODS

Porous polyethylene discs were loaded with either fibroblasts or hUCB-MSCs, and a third group, which served as a control, was not loaded with cells. The discs were then implanted in the back of diabetic mice. During the first and the second week after implantation, the discs were harvested, and collagen level and microvascular density were compared.

RESULTS

In terms of collagen synthesis, the hUCB-MSC group showed the highest collagen level (117.7 ± 8.9 ng/mL), followed by the fibroblast group (83.2 ± 5.2 ng/mL) and the no-cell group (60.0 ± 4.7 ng/mL) in the second week after implantation. In terms of angiogenesis, the microvascular density in the hUCB-MSC group was 56.8 ± 16.4, which was much higher than that in the fibroblast group (14.3 ± 4.0) and the no-cell group (5.7 ± 2.1) in the second week after implantation.

CONCLUSIONS

These results demonstrate that hUCB-MSCs are superior to fibroblasts in terms of their effect on diabetic wound healing in vivo.

Diabetic ulcer regeneration: stem cells, biomaterials, growth factors

The impairment of ulcer wound healing in diabetic patients is a vital clinical problem affecting millions of patients. Several clinical and basic science studies have demonstrated that stem cell therapy, to be effective in healing diabetic ulcer. Furthermore, these ulcer wounds may be healed from molecular maneuvering of growth factors to improve microcirculation within the ulcer wound. In addition, ulcer wound dressings may be employed as medicated systems, through the delivery of drugs, growth factors, peptides and stem cells. These dressing materials can include natural, modified and synthetic polymers, as well as their mixtures or combinations. This review paper will give a summary of some of the recent advances on the application of stem cells, biomaterials and growth factors in the treatment of diabetic ulcer wound.

Impact of Cryopreservation on Caprine Fetal Adnexa Derived Stem Cells and Its Evaluation for Growth Kinetics, Phenotypic Characterization, and Wound Healing Potential in Xenogenic Rat Model

This study was conducted to know the impact of cryopreservation on caprine fetal adnexa derived mesenchymal stem cells (MSCs) on the basic stem cell characteristics. Gravid caprine uteri (2-3 months) were collected from local abattoir to derive (amniotic fluid [cAF], amniotic sac [cAS], Wharton's jelly [cWJ], and cord blood [cCB]) MSCs and expanded in vitro. Cells were cryopreserved at 3rd passage (P3) using 10% DMSO. Post-thaw viability and cellular properties were assessed. Cells were expanded to determine growth kinetics, tri-lineage differentiation, localization, and molecular expression of MSCs and pluripotency markers; thereafter, these cells were transplanted in the full-thickness (2 × 2cm² ) rat skin wound to determine their wound healing potential. The post-thaw (pt) growth kinetics study suggested that cWJ MSCs expanded more rapidly with faster population doubling time (PDT) than that of other fetal adnexa MSCs. The relative mRNA expression of surface antigens (CD73, CD90, and CD 105) and pluripotency markers (Oct4, KLF, and cMyc) was higher in cWJ MSCs in comparison to cAS, cAF, and cCB MSCs post-thaw. The percent wound contraction on 7th day was more than 50% for all the MSC-treated groups (pre and post-thaw), against 39.55% in the control group. On day 28th, 99% and more wound contraction was observed in cAF, cAF-pt, cAS-pt, cWJ, cWJ-pt, and cCB, MSCs with better scores for epithelization, neovascularization, and collagen characteristics at a non-significant level. It is concluded that these MSCs could be successfully cryopreserved without altering their stemness and wound healing properties. J. Cell. Physiol. 232: 2186-2200, 2017. © 2016 Wiley Periodicals, Inc.

Mesenchymal Stem Cells as a Prospective Therapy for the Diabetic Foot

The diabetic foot is a serious complication of diabetes. Mesenchymal stem cells are an abundant source of stem cells which occupy a special position in cell therapies, and recent studies have suggested that mesenchymal stem cells can play essential roles in treatments for the diabetic foot. Here, we discuss the advances that have been made in mesenchymal stem cell treatments for this condition. The roles and functional mechanisms of mesenchymal stem cells in the diabetic foot are also summarized, and insights into current and future studies are presented.

Epidermal stem cells (ESCs) accelerate diabetic wound healing via the Notch signalling pathway

Epidermal stem cells (ESCs) accelerate diabetic wound healing via the Notch signalling pathway.

Chronic, non-healing wounds are a major complication of diabetes. Recently, various cell therapies have been reported for promotion of diabetic wound healing. Epidermal stem cells (ESCs) are considered a powerful tool for tissue therapy. However, the effect and the mechanism of the therapeutic properties of ESCs in the diabetic wound healing are unclear. Herein, to determine the ability of ESCs to diabetic wound healing, a dorsal skin defect in a streptozotocin (STZ)-induced diabetes mellitus (DM) mouse model was used. ESCs were isolated from mouse skin. We found that both the mRNA and protein levels of a Notch ligand Jagged1 (Jag1), Notch1 and Notch target gene Hairy Enhancer of Split-1 (Hes1) were significantly increased at the wound margins. In addition, we observed that Jag1 was high expressed in ESCs. Overexpression of Jag1 promotes ESCs migration, whereas knockdown Jag1 resulted in a significant reduction in ESCs migration in vitro. Importantly, Jag1 overexpression improves diabetic wound healing in vivo. These results provide evidence that ESCs accelerate diabetic wound healing via the Notch signalling pathway, and provide a promising potential for activation of the Notch pathway for the treatment of diabetic wound.

The Effect of Mesenchymal Stem Cells and Chitosan Gel on Full Thickness Skin Wound Healing in Albino Rats: Histological, Immunohistochemical and Fluorescent Study

Background

Wound healing involves the integration of complex biological processes. Several studies examined numerous approaches to enhance wound healing and to minimize its related morbidity. Both chitosan and mesenchymal stem cells (MSCs) were used in treating skin wounds. The aim of the current work was to compare MSCs versus chitosan in wound healing, evaluate the most efficient route of administration of MSCs, either intradermal or systemic injection, and elicit the mechanisms inducing epidermal and dermal cell regeneration using histological, immunohistochemical and fluorescent techniques.

Material and Methods

Forty adult male Sprague Dawley albino rats were divided into four equal groups (ten rats in each group): control group (Group I); full thickness surgical skin wound model, Group II: Wound and chitosan gel. Group III: Wound treated with systemic injection of MSCs and Group IV: Wound treated with intradermal injection of MSCs. The healing ulcer was examined on day 3, 5, 10 and 15 for gross morphological evaluation and on day 10 and 15 for histological, immunohistochemical and fluorescent studies.

Results

Chitosan was proved to promote wound healing more than the control group but none of their wound reached complete closure. Better and faster healing of wounds in MSCs treated groups were manifested more than the control or chitosan treated groups. It was found that the intradermal route of administration of stem cells enhanced the rate of healing of skin wounds better than the systemic administration to the extent that, by the end of the fifteenth day of the experiment, the wounds were completely healed in all rats of this group. Histologically, the wound areas of group IV were hardly demarcated from the adjacent normal skin and showed complete regeneration of the epidermis, dermis, hypodermis and underlying muscle fibers. Collagen fibers were arranged in many directions, with significant increase in their area percent, surrounding fully regenerated hair follicles and sebaceous glands in the dermis of the healed areas more than in other groups.

Conclusion

MSCs enhanced the healing process of wound closure more than chitosan gel treatment. Furthermore, MSCs injected intradermally, were more efficient in accelerating wound healing than any other mode of treatment.

VEGF gene transfected umbilical cord mesenchymal stem cells transplantation improve the lower limb vascular lesions of diabetic rats

BACKGROUND

Previous studies had explored the therapeutic effect of hUC-MSCs transplantation on ischemia; in this study, we further assessed the effectiveness of VEGF over-expressed hUC-MSCs cells transplantation on vascular proliferation in lower limb ischemia model in type 2 diabetic rats.

METHODS

hUC-MSCs cells were over-expressed with VEGF, and transplanted to lower limb ischemia rats model of type 2 diabetes.

RESULTS

VEGF over-expression increased the hUC-MSCs cells proliferation activity and VEGF secretion. VEGF gene transfected hUC-MSCs transplantation increased VEGF expression at a high level throughout 4weeks in skeletal muscle tissues of rats. Importantly, the vascular proliferation and blood perfusion of VEGF over-expressed hUC-MSCs transplanted limb were significantly improved compared with those of control group. The expression levels of ERK, AKT, MMP2 and MMP9 in VEGF over-expressed hUC-MSCs transplantation group increased dramatically compared with control group, while TIMP1 and TIMP2 expression had no significant change.

CONCLUSION

VEGF over-expressed hUC-MSCs transplantation was more effective to stimulate angiogenesis and increase blood perfusion than the simply hUC-MSCs transplantation, as maybe a new choice to improve the lower limb vascular lesions of diabetics.

The role of placenta-derived mesenchymal stem cells in healing of induced full-thickness skin wound in a mouse model

We examined the effect of placenta-derived MSCs (PDMSCs) injection intraregionally and intraperitoneally on healing of induced full thickness mice skin wounds; moreover, the mechanisms by which MSCs exert their effects were also studied. Sixty female mice were divided into three groups after induction of full thickness skin wound; untreated group, wounded mice were injected with MSCs derived from human placenta intraperitoneally or intraregionally. Skin biopsies were obtained 7 and 12 days after wound incision for histological examinations, detection of vascular endothelial growth factor (VEGF) by ELISA, and estimation of expression of mouse ICAM-1, Integrin β1, Integrin β3 genes and human albumin and GAPDH genes by reverse transcription polymerase chain reaction. Human placenta derived-MSCs treated groups showed accelerated wound healing than non-treated group. VEGF, Integrin β1, and Integrin β3 levels were significantly increased in the intraregionally and intraperitoneally treated mice as compared to non-treated group at day 7 after wound induction. ICAM-1 showed significant decrease in its expression in treated groups compared with non-treated group. Interestingly, the intraperitoneal MSCs injections showed better results than intraregional one. PDMSCs accelerate full thickness skin wound healing and the intraperitoneal MSCs injections are more effective than intraregional one. MSCs promote wound healing through release of proangiogenic factors as VEGF, increase healing promoting factors as integrin β1 and β3, and decrease proinflammatory cytokines as ICAM-1.

Skin-derived precursor cells promote wound healing in diabetic mice

BACKGROUND

Impaired wound healing as one of the complications arising from diabetes mellitus is a serious clinical issue. Recently, various cell therapies have been reported for promotion of wound healing. Skin-derived precursor cells (SKPs) are multipotent adult stem cells with the tendency to differentiate into neurons. We investigated the potency of promoting diabetic wound healing by the application of SKPs.

METHODS

Skin-derived precursor cells isolated from diabetic murine skin were cultured in sphere formation medium. At passage 2, they were suspended in phosphate-buffered saline (PBS), and applied topically to full-thickness excisional cutaneous wounds in diabetic mice. Application of PBS served as controls (n = 21 for each group; n = 42 total). Time to closure and percentage closure were calculated by morphometry. Wounds were harvested at 10 and 28 days and then processed, sectioned, and stained (CD31, α-smooth muscle actin, and neurofilament heavy chain) to quantify vascularity and neurofilaments.

RESULTS

Wounds treated with SKPs demonstrated a significantly decreased time to closure (18.63 days) compared with PBS-control wounds (21.72 days, P < 0.01), and a significant improvement in percentage closure at 7, 10, 14, and 18 days compared with PBS-control wounds (P < 0.01). Histological analysis showed that the Capillary Score (the number of vessels/mm2) was significantly higher in SKP-treated wounds at day 10 but not at day 28. Nerve Density (the number of neurofilaments/mm2) had increased significantly in SKP-treated wounds at day 28 compared with control group. Some applied SKPs were stained by neurofilament heavy chain, which demonstrates that SKPs directly differentiated into neurons.

CONCLUSIONS

Skin-derived precursor cells promoted diabetic wound healings through vasculogenesis at the early stage of wound healing. Skin-derived precursor cells are a possible therapeutic tool for diabetic impaired wound healing.

Mesenchymal stem cell-based therapy for nonhealing wounds: today and tomorrow

Although advancements have been made with traditional therapies, the treatment of chronic nonhealing wounds still remains a tough challenge. In the past two decades, mesenchymal stem cell (MSC)-based therapy has emerged as a promising therapeutic strategy for nonhealing wounds because of their characteristics including self-renewal and a multidirectional differentiation ability and their easy collection and weak immunogenicity. There is a growing body of basic scientific studies that shed light on the functional mechanism of MSCs in modulating nonhealing wounds. Furthermore, critical advances have been achieved using MSC-based therapy in preclinical animal models as well as in clinics trials. In this present review, we summarize the mechanisms of MSCs and highlight the important preclinical and clinical trials of MSC therapy for nonhealing wounds. In particular, the combination of MSCs transplantation and tissue-engineered skin is addressed as a new strategy to optimize the delivery efficiency and therapeutic potential. Additionally, the current drawbacks of MSC therapy and the potential to further optimize the use of MSCs are implied.

Wound-healing potential of human umbilical cord blood-derived mesenchymal stromal cells in vitro--a pilot study

BACKGROUND AIMS

Our previous studies demonstrated that human bone marrow-derived mesenchymal stromal cells have great potential for wound healing. However, it is difficult to clinically utilize cultured stem cells. Recently, human umbilical cord blood-derived mesenchymal stromal cells (hUCB-MSCs) have been commercialized for cartilage repair as a first cell therapy product that uses allogeneic stem cells. Should hUCB-MSCs have a superior effect on wound healing as compared with fibroblasts, which are the main cell source in current cell therapy products for wound healing, they may possibly replace fibroblasts. The purpose of this in vitro study was to compare the wound-healing activity of hUCB-MSCs with that of fibroblasts.

METHODS

This study was particularly designed to compare the effect of hUCB-MSCs on diabetic wound healing with those of allogeneic and autologous fibroblasts. Healthy (n = 5) and diabetic (n = 5) fibroblasts were used as the representatives of allogeneic and autologous fibroblasts for diabetic patients in the control group. Human UCB-MSCs (n = 5) were used in the experimental group. Cell proliferation, collagen synthesis and growth factor (basic fibroblast growth factor, vascular endothelial growth factor and transforming growth factor-β) production were compared among the three cell groups.

RESULTS

Human UCB-MSCs produced significantly higher amounts of vascular endothelial growth factor and basic fibroblast growth factor when compared with both fibroblast groups. Human UCB-MSCs were superior to diabetic fibroblasts but not to healthy fibroblasts in collagen synthesis. There were no significant differences in cell proliferation and transforming growth factor-β production.

CONCLUSIONS

Human UCB-MSCs may have greater capacity for diabetic wound healing than allogeneic or autologous fibroblasts, especially in angiogenesis.

Wound management of chronic diabetic foot ulcers: from the basics to regenerative medicine

BACKGROUND

Hospital-based studies have shown that mortality rates in individuals with diabetic foot ulcers are about twice those observed in individuals with diabetes without foot ulcers.

OBJECTIVE

To assess the etiology and management of chronic diabetic foot ulcers.

STUDY DESIGN

Literature review.

METHODS

Systematic review of the literature discussing management of diabetic foot ulcers. Since there were only a few randomized controlled trials on this topic, articles were selected to attempt to be comprehensive rather than a formal assessment of study quality.

RESULTS

Chronic nonhealing foot ulcers occur in approximately 15% of patients with diabetes. Many factors contribute to impaired diabetic wound healing. Risk factors include peripheral neuropathy, peripheral arterial disease, limited joint mobility, foot deformities, abnormal foot pressures, minor trauma, a history of ulceration or amputation, and impaired visual acuity. With the current treatment for nonhealing diabetic foot ulcers, a significant number of patients require amputation.

CONCLUSION

Diabetic foot ulcers are optimally managed by a multidisciplinary integrated team. Offloading and preventative management are important. Dressings play an adjunctive role. There is a critical need to develop novel treatments to improve healing of diabetic foot ulcers. The goal is to have wounds heal and remain healed.

CLINICAL RELEVANCE

Diabetic neuropathy and peripheral arterial disease are major factors involved in a diabetic foot ulcer. Despite current treatment modalities for nonhealing diabetic foot ulcers, there are a significant number of patients who require amputations. No known therapy will be effective without concomitant management of ischemia, infection, and adequate offloading.

Preclinical and clinical evidence for stem cell therapies as treatment for diabetic wounds

Diabetic wounds remain a global unsolved problem and the cost of diabetes-related amputations and diabetic wound treatment is approximately US$3 billion and US$9 billion per year, respectively. Diabetic foot ulcers (DFUs) occur in 15% of all patients with diabetes and precede 84% of all diabetes-related lower leg amputations. Currently, there is no satisfying treatment for these hard-to-heal-wounds. However, as we discuss here, experimental preclinical evidence for the successful use of adult stem cell therapies for diabetic wounds gives new hope for the development of effective treatments for use in the clinic.

Molecular characterization and xenogenic application of Wharton's jelly derived caprine mesenchymal stem cells

Aim of the present study was in vitro expansion and characterization of caprine wharton's jelly derived mesenchymal stem cells (cWJ-MSCs) to investigate their tissue healing potential in xenogenic animal model. Plastic adherent fibroblastoid cell populations with distinctive homogeneous morphology were isolated from caprine Wharton's jelly explants. These Wharton's jelly derived cells were found positive for the surface markers CD-73, STRO-1 and CD-105, whereas they were negative for hematopoetic stem cell marker CD-34. In vitro cultured cWJ-MSCs also showed differentiation properties into osteogenic, adipogenic and chondrogenic lineages as demonstrated by von Kossa, Oil Red-O and Alcian blue staining respectively, which was further confirmed and quantified by flow cytometric analysis. Furthermore, these well characterized cWJ-MSCs were evaluated for the wound-healing potential in full-thickness skin wounds in rabbit model for 28 days. Caprine WJ- MSCs treated skin wounds showed significantly (P < 0.05) higher percentage of wound contraction especially at the 21(st) day post transplantation when compared to PBS treated control group animals. Further, we observed better healing potential of cWJ-MSCs in terms of histo-morphological evaluation, epithelialisation and collagenization with matured vascularization stage by day 28 as compared to control. In conclusion, cWJ- MSCs provide an alternative inexhaustible source of mesenchymal stem cells and also unravel new perspectives pertaining to the therapeutic use of these cells in different species.

Effect of bone marrow derived mesenchymal stem cells on healing of induced full-thickness skin wounds in albino rat

BACKGROUND AND OBJECTIVES

Mesenchymal stem cells have delivered new approaches to the management of wound healing in severe skin injuries. This work was planned to evaluate the effect of bone marrow-derived mesenchymal stem cells (BMSCs) on healing of induced full thickness skin wounds in albino rats using topical & systemic injections.

METHODS AND RESULTS

Forty adult male albino rats were classified into 2 groups after induction of full thickness skin wound; untreated group and stem cell-treated group. The latter was further subdivided into topically and systemically treated ones. BMSCs were isolated & labeled by PKH26 before injection. Healing of wounds was evaluated grossly. Skin biopsies were obtained one & three weeks after wound induction. Sections were stained with Hematoxylin & Eosin, Masson's trichrome and immunohistochemichal stain for vascular endothelial growth factor (VEGF). Epidermal thicknesses and mean area percent of both collagen fibers & VEGF immunopositive cells were measured using image analyzer & results were subjected to statistical analysis. PKH26 fluorescent-labeled cells were found in the regenerated epidermis, hair follicles and dermis in BMSCs-treated groups. By the end of the third week, the wounds of BMSCs-treated groups showed full regeneration of epidermis, re-organization of collagen and decrease in VEGF immunopositive cells. Delayed wound healing was seen in 20% of systemically treated rats. Significant increase in the mean area percent of collagen fibers was detected in topically treated group.

CONCLUSIONS

Both methods of BMSCs injection were effective in healing of full thickness skin wound but topical method was more effective.

Local application of periodontal ligament stromal cells promotes soft tissue regeneration

OBJECTIVES

To test the potential stimulatory effect of local application of periodontal ligament (PDL) stromal cells on soft tissue regeneration.

MATERIALS AND METHODS

Fluorescently labeled PDL cells outgrown from extracted human premolars or phosphate-buffered saline were locally injected to the cutaneous wounds created on mice. Soft tissue regeneration was evaluated for 14 days using photographs and histomorphometry. PDL cell engraftment was tracked with confocal microscopy. To detect the paracrine effect of the PDL cells on soft tissue regeneration, PDL cell-conditioned medium (CM) was evaluated for the concentration of secretory factors, transforming growth factor-beta 1 (TGFβ1). The effect of PDL CM on the proliferation and migration of dermal fibroblast and keratinocyte was tested using MTT assay and migration assay.

RESULTS

The application of PDL cells significantly promoted soft tissue regeneration compared with the application of PBS. Self-replicating PDL cells were engrafted into the hair follicles of the host tissue. Dermal fibroblast proliferation and keratinocyte migration were significantly enhanced by the treatment with PDL CM. Physiologically significant amount of TGFβ1 was secreted from PDL cells into the CM.

CONCLUSION

Local injection of PDL cells promoted soft tissue regeneration in part by the enhancement of fibroblast proliferation and keratinocyte migration through a paracrine mechanism.

Topical administration of allogeneic mesenchymal stromal cells seeded in a collagen scaffold augments wound healing and increases angiogenesis in the diabetic rabbit ulcer

There is a critical clinical need to develop therapies for nonhealing diabetic foot ulcers. Topically applied mesenchymal stromal cells (MSCs) provide a novel treatment to augment diabetic wound healing. A central pathological factor in nonhealing diabetic ulcers is an impaired blood supply. It was hypothesized that topically applied allogeneic MSCs would improve wound healing by augmenting angiogenesis. Allogeneic nondiabetic bone-marrow derived MSCs were seeded in a collagen scaffold. The cells were applied to a full-thickness cutaneous wound in the alloxan-induced diabetic rabbit ear ulcer model in a dose escalation fashion. Percentage wound closure and angiogenesis at 1 week was assessed using wound tracings and stereology, respectively. The topical application of 1,000,000 MSCs on a collagen scaffold demonstrated increased percentage wound closure when compared with lower doses. The collagen and collagen seeded with MSCs treatments result in increased angiogenesis when compared with untreated wounds. An improvement in wound healing as assessed by percentage wound closure was observed only at the highest cell dose. This cell-based therapy provides a novel therapeutic strategy for increasing wound closure and augmenting angiogenesis, which is a central pathophysiological deficit in the nonhealing diabetic foot ulcer.

Effects of MSC Coadministration and Route of Delivery on Cord Blood Hematopoietic Stem Cell Engraftment

Hematopoietic stem cell transplantation (HSCT) using umbilical cord blood (UCB) progenitors is increasingly being used. One of the problems that may arise after UCB transplantation is an impaired engraftment. Either intrabone (IB) injection of hematopoietic progenitors or mesenchymal stem cell (MSC) coadministration has been proposed among the strategies to improve engraftment. In the current study, we have assessed the effects of both approaches. Thus, NOD/SCID recipients were transplanted with human UCB CD34+ cells administered either intravenously (IV) or IB, receiving or not bone marrow (BM)-derived MSCs also IV or IB (in the right femur). Human HSC engraftment was measured 3 and 6 weeks after transplantation. Injected MSCs were tracked weekly by bioluminescence. Also, lodgment within the BM niche was assessed at the latter time point by immunofluorescence. Our study shows regarding HSC engraftment that the number of BM human CD45+ cells detected 3 weeks after transplantation was significantly higher in mice cotransplanted with human MSCs. Moreover, these mice had a higher myeloid (CD13+) engraftment and a faster B-cell (CD19+) chimerism. At the late time point evaluated (6 weeks), human engraftment was higher in the group in which both strategies were employed (IB injection of HSC and MSC coadministration). When assessing human MSC administration route, we were able to track MSCs only in the injected femurs, whereas they lost their signal in the contralateral bones. These human MSCs were mainly located around blood vessels in the subendosteal region. In summary, our study shows that MSC coadministration can enhance HSC engraftment in our xenogenic transplantation model, as well as IB administration of the CD34+ cells does. The combination of both strategies seems to be synergistic. Interestingly, MSCs were detected only where they were IB injected contributing to the vascular niche.

The effects of rat mesenchymal stem cells on injury progression in a rat model

OBJECTIVES

Burns are common injuries that can result in significant scarring, leading to poor function and disfigurement. Unlike mechanical injuries, burns often progress both in depth and in size over the first few days after injury, possibly due to inflammation and oxidative stress. A major gap in the field of burns is the lack of an effective therapy that reduces burn injury progression. Because stem cells have been shown to improve healing in several injury models, the authors hypothesized that species-specific mesenchymal stem cells (MSCs) would reduce injury progression in a rat comb-burn model.

METHODS

Using a brass comb preheated to 100°C, the authors created four rectangular burns, separated by three unburned interspaces on both sides of the backs of male Sprague-Dawley rats. The interspaces represented the ischemic zones surrounding the central necrotic core. In an attempt to reduce burn injury progression, 20 rats were randomized to tail vein injections of 1 mL of rat-specific MSCs, 10(6) cells/mL (n = 10), or normal saline (n = 10), 60 minutes after injury.

RESULTS

While the authors were unable to identify any quantum dot (Q-dot)-labeled MSCs in the injured skin, at 7 days the mean percentage of the unburned interspaces that became necrotic in the MSC group was significantly less than in the control group (80% vs. 100%, p < 0.0001).

CONCLUSIONS

Intravenous injection of rat MSCs reduced burn injury progression in a rat comb-burn model.

Do mesenchymal stem cells function across species barriers? Relevance for xenotransplantation

BACKGROUND

Allogeneic mesenchymal stem (stromal) cells (MSC) are a promising therapy for various pathological conditions. Genetically modified pig MSC have been demonstrated to downregulate the human T-cell response to pig antigens in vitro. Before genetically modified pig MSC can be used clinically, however, evidence needs to be provided to indicate whether they will survive in a human (xenogeneic) host.

LITERATURE SEARCH AND RESULTS

A literature search through the end of 2011 identified 94 reports of the in vivo cross-species administration of MSC in a variety of experimental models. The majority (n = 89) involved the use of human MSC in various other species, with an occasional study using pig, rat, or guinea-pig MSC. When human MSC were used, they were largely derived from the bone marrow, adipose tissue, or umbilical cord blood. The routes of administration were varied, although almost half of the studies utilized the intravenous route. In 88 experiments (93.6%), there was evidence that the MSC engrafted and functioned across the species barrier, and in only six cases (6.4%) was there evidence of failure to function. Importantly, MSC function was confirmed in several different cross-species models. For example, human MSC functioned in no fewer than seven different recipient species.

CONCLUSIONS

The data provided by this literature search strengthen the hypothesis that pig MSC will function satisfactorily in a different species, for example, humans. The data also suggest that our own in vitro observations on the efficacy of pig MSC in downregulating the strength of the human T-cell response to pig antigens will likely be reproduced in vivo in pre-clinical large animal models and in clinical trials.

Enhanced healing of diabetic wounds by subcutaneous administration of human umbilical cord derived stem cells and their conditioned media

Objective. Mesenchymal stem cells (MSCs) isolated from the umbilical cord and their conditioned media (CM) can be easily obtained and refined compared with stem cells from other sources. Here, we explore the possibility of the benefits of these cells in healing diabetic wounds. Methodology and Results. Delayed wound healing animal models were established by making a standard wound on the dorsum of eighteen db/db mice, which were divided into three groups with six mice in each: groups I, II, and III received PBS, UC-MSC, and CM, respectively. UC-MSC and their CM significantly accelerated wound closure compared to PBS-treated wounds, and it was most rapid in CM-injected wounds. In day-14 wounds, significant difference in capillary densities among the three groups was noted (n = 6; P < 0.05), and higher levels of VEGF, PDGF, and KGF expression in the CM- and UC-MSC-injected wounds compared to the PBS-treated wounds were seen. The expression levels of PDGF- β and KGF were higher in CM-treated wounds than those in UC-MSC-treated wounds. Conclusion. Both the transplantation of UC-MSC and their CM are beneficial to diabetic wound healing, and CM has been shown to be therapeutically better than UC-MSC, at least in the context of diabetic wound healing.

The effect of heme oxygenase-1 complexed with collagen on MSC performance in the treatment of diabetic ischemic ulcer

Diabetic ischemic ulcer is an intractable diabetic complication. Bone marrow mesenchymal stem cells (BMSCs) have great potential in variety of tissue repair. In fact, poor cell viability and tolerance limit their ability for tissue repair. In addition, it is difficult for stem cells to home and locate to the lesion. In this study, we explore whether over-expression of heme oxygenase-1 (HO-1) in BMSCs complexed with collagen play an important role in treatment of diabetic ischemic ulcers. In vitro, over-expression of HO-1 promoted the proliferation and paracrine activity of BMSCs and the conditioned medium of BMSCs accelerated HUVECs migration and proliferation. These processes were closely related to Akt signaling pathway and were not dependent on Erk signaling pathway. In vivo, in order to make BMSCs directly act on the wound, we choose a solid collagen as a carrier, BMSCs were planted into it, ischemic wounds of diabetic mice were covered with the complex of BMSCs and collagen. The results indicate that the complex of HO-1-overexpressing BMSCs and collagen biomaterials can significantly promote angiogenesis and wound healing. These preclinical findings open new perspectives for the treatment of diabetic foot ulcers.

Progress in stem cell therapy for the diabetic foot

The diabetic foot is a common and severe complication of diabetes comprising a group of lesions including vasculopathy, neuropathy, tissue damage and infection. Vasculopathy due to ischemia is a major contributor to the pathogenesis, natural history and outcome of the diabetic foot. Despite conventional revascularization interventions including angioplasty, stenting, atherectomy and bypass grafts to vessels, a high incidence of amputation persists. The need to develop alternative therapeutic options is compelling; stem cell therapy aims to increase revascularization and alleviate limb ischemia or improve wound healing by stimulating new blood vessel formation, and brings new hope for the treatment of the diabetic foot.

The role of stem cells in the treatment of diabetic foot ulcers

Diabetic foot ulcers (DFUs) are a significant and rapidly growing complication of diabetes and its effects on wound healing. Over half of diabetic patients who develop a single ulcer will subsequently develop another ulcer of which the majority will become chronic non-healing ulcers. One-third will progress to lower extremity amputation. Over the past decade, the outcomes for patients with DFUs ulcers have not improved, despite advances in wound care. Successful treatment of diabetic foot ulcers is hindered by the lack of targeted therapy that hones in on the healing processes dysregulated by diabetes. Stem cells are a promising treatment for DFUs as they are capable of targeting, as well as bypassing, the underlying abnormal healing mechanisms and deranged cell signaling in diabetic wounds and promote healing. This review will focus on existing stem cell technologies and their application in the treatment of DFUs.

An examination of regenerative medicine-based strategies for the urinary bladder

Patients that are afflicted with dysfunctional urinary bladders due to developmental defect, trauma or malignant transformation have limited treatment options that would allow for complete recapitulation of the urinary bladder. Hence, novel tissue engineering techniques that are successful in regenerating functional urinary bladder tissue for replacement therapy would be invaluable. Current tissue engineering techniques are hampered by several problems including choice of appropriate cell type, inadequate development of new blood vessels to the regenerated tissue, tissue innervation and primitive bioscaffold design. This article describes the recent advances in stem cell biology and the material sciences to address these problems, and attempts to improve upon current tissue engineering techniques to make successful regeneration of urinary bladder tissue a reality.

Stem Cell Therapy: A New Treatment for Burns?

Stem cell therapy has emerged as a promising new approach in almost every medicine specialty. This vast, heterogeneous family of cells are now both naturally (embryonic and adult stem cells) or artificially obtained (induced pluripotent stem cells or iPSCs) and their fates have become increasingly controllable, thanks to ongoing research in this passionate new field. We are at the beginning of a new era in medicine, with multiple applications for stem cell therapy, not only as a monotherapy, but also as an adjunct to other strategies, such as organ transplantation or standard drug treatment. Regrettably, serious preclinical concerns remain and differentiation, cell fusion, senescence and signalling crosstalk with growth factors and biomaterials are still challenges for this promising multidisciplinary therapeutic modality. Severe burns have several indications for stem cell therapy, including enhancement of wound healing, replacement of damaged skin and perfect skin regeneration - incorporating skin appendages and reduced fibrosis -, as well as systemic effects, such as inflammation, hypermetabolism and immunosuppression. The aim of this review is to describe well established characteristics of stem cells and to delineate new advances in the stem cell field, in the context of burn injury and wound healing.

Mesenchymal stem cells: from experiment to clinic

There is currently much interest in adult mesenchymal stem cells (MSCs) and their ability to differentiate into other cell types, and to partake in the anatomy and physiology of remote organs. It is now clear these cells may be purified from several organs in the body besides bone marrow. MSCs take part in wound healing by contributing to myofibroblast and possibly fibroblast populations, and may be involved in epithelial tissue regeneration in certain organs, although this remains more controversial. In this review, we examine the ability of MSCs to modulate liver, kidney, heart and intestinal repair, and we update their opposing qualities of being less immunogenic and therefore tolerated in a transplant situation, yet being able to contribute to xenograft models of human tumour formation in other contexts. However, such observations have not been replicated in the clinic. Recent studies showing the clinical safety of MSC in several pathologies are discussed. The possible opposing powers of MSC need careful understanding and control if their clinical potential is to be realised with long-term safety for patients.

Effects of transplanted mesenchymal stem cells isolated from Wharton's jelly of caprine umbilical cord on cutaneous wound healing; histopathological evaluation

The aim of this study was to investigate the effects of transplanted Wharton's jelly mesenchymal stem cells (WJMSCs) of caprine umbilical cord on cutaneous wound healing process in goat. After collection of caprine pregnant uterus of mixed breed goats from abattoir, the Wharton's jelly (WJ) of umbilical cord was harvested. The tissues were minced in ventilated flasks and explant culture method was used for separating mesenchymal stem cells (MSCs). The isolated cells were immunostained for Actin protein, histochemically assayed for the presence of alkaline phosphatase activity, and analyzed for detection of matrix receptors (CD44) and hematopoetic lineage markers (CD34), using flow cytometery. After The isolated cells, 3×10(6) MSCs were stained with BrdU and prepared for transplantation to each wound. Four 3-cm linear full thickness skin incisions were made on both sides of thoracic vertebrate of four Raeini goats (two wounds on each side). The left wounds were implanted with MSCs in 0.6 ml of Phosphate buffer saline (PBS), and the right wounds considered as control group that received 0.6 ml of PBS. The samples were taken from the wounds 7 and 12 days after the wounding, and healing process was compared histologically between the two groups. Anti-BrdU staining showed that the transplanted cells were still alive in the wound bed during the study. The histopathological study revealed that re-epithelialization was complete at days 7 in treated wounds with WJMSCs, whereas in control wound the wounds still showed incomplete epithelialization 12 days after wounding. Also, microscopic evaluation showed less inflammation, thinner granulation tissue formation with minimum scar in the treated wounds in comparison with control wounds. In conclusion, this study demonstrates the beneficial effect of caprine WJMSCs in cutaneous wound healing in goat.