The Potentials of Human Cord Mesenchymal Stem Cells in Wound Healing

The MSCs have been shown to possess a strong ability to improve tissue damage in response to skin injury, by contributing to collagen deposition, wound contraction, angiogenesis, regeneration of skin appendages, and enhanced growth of epidermal cells. Currently, most of the studies related to MSCs in clinical treatments are on BMMSCs; only limited studies mentioned the ap-plication of WJMSCs. However, the process of obtaining the umbilical cord-derived MSCs is much easier and does not harm the donor, compared with that of BMMSCs. Similar to BMMSCs, MSCs derived from Wharton’s Jelly can adapt to the culture conditions of the dermal equiva lents (DEs), suggesting that WJMSCs confer a therapeutic benefit by supporting the regeneration of the dermal compartment. Interestingly, a small population of WJMSCs coexpresses the mesenchymal marker vimentin and the epithelial marker pan-cytokeratin (CK). By contrast, BMMSCs are CK-negative after isolation and on DEs. Compared with BMMSCs, WJMSCs can survive on DEs and can adapt more easily to the culture conditions of the skin. Therefore, WJMSCs can promote skin epithelization, vasculogenesis, and collagen deposition, by secreting a number of soluble factors, during the wound healing phase. Therefore, WJMSCs can be used as an interesting and promising tool to regenerate skin wounds. The res toration of cutaneous appendages, after a severe skin in jury, which is related to the function of the regenerated skin and affects the quality of life, may be an important function of WJMSCs during skin repair. The regeneration of sweat glands, after deep burns, has been an unresolved challenge. To address this problem, our group previously induced BMMSCs to acquire the phenotype of sweat gland cells in vitro and then transplanted them into fresh skin wounds, made by excising the anhidrotic scars of five patients after their deep burn injuries were healed. The MSCs transformed into sweat gland cells and facilitated the recovery of functional sweat glands. This phenomenon may help address the problem of sweat gland depletion in patients surviving extensive deep burns. The WJMSCs, in a specific induction system, may hopefully differentiate into sweat gland cell-like cells. Recently, WJM SCs were successfully induced to differentiate into sweat gland cells in vitro. Studies indicated that WJMSCs can differentiate into sweat gland-like cells, via a novel and feasible system that is more effective than our previ ous method. The WJMSCs, as a novel source of stem cells, can differentiate into sweat glands, for further re-generation of the epidermis and skin appendages.As a challenge that WJMSC transplantation has not yet been approved by the Food and Drug Administration and that clinical trials of MSC transplantation, showing no adverse events, have not yet reached the 10-year mark, WJMSCs have not been extensively used for clinical thera pies. In addition, a number of challenges and side effects in WJMSC-based therapy remain to be addressed. First, the umbilical cord is an allogeneic tissue for the recipient. The second problem is an ethical one. Although the umbilical cord is a disused organ, both the donor and the recipient have the right of informed consent. Third, a complete de tection system, to test any potential disease risk in donors, has yet to be established. Fourth, the isolation and further expansion of primitive MSCs probably have several un certain factors, such as the use of animal serum and the most common culture method in vitro, which should be avoided in clinical-grade therapy to prevent cell contact with xenogeneic proteins. Fifth, potential long term risks associated with MSC therapy that may not have been ob servable within a short period, after administrations have recently been confirmed in preclinical studies. These risks include potential maldifferentiation, immunosuppres sion and malignant tumor growth, which are the primary safety concern, as well as the promotion of tumor growth, when the treatment was systemically administered into animals with coexisting malignancy. Lastly, as products of cell therapy, product consistency, cell stabil ity, and toxicity should also be considered.

کلیدواژه ها:

Cord ، Mesenchymal Stem Cells ، Wound Healing