Bone Marrow-derived Mesenchymal Stem Cells Transplantation Accelerates Tissue Expansion by Promoting Skin Regeneration During Expansion

Objective: To evaluate the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) transplantation on tissue expansion. Background: Tissue expansion provides a better solution to large defect reconstruction with perfectly matched skin and without deformity at the donor site. How to promote tissue expansion and reduce complications has been a focus in this field. BM-MSCs have been found to exhibit tissue regeneration-promoting ability, but their effect on skin growth during tissue expansion has remained unclear. Methods: BM-MSCs transplantation was performed on a rat tissue expansion model. Inflation volume, expansion time, and area were examined to determine the effect on tissue expansion. Factors related to skin regeneration were examined to evaluate BM-MSCs' role in skin regeneration during expansion. The mechanism was explored by in vivo and in vitro experiments. Results: Higher inflation volume, larger expansion area, and shorter expansion time could be achieved by BM-MSCs transplantation (all P < 0.05). The skin regeneration during expansion was enhanced by BM-MSCs treatment, as evidenced by a thicker epidermis and further evidenced by increased cell proliferation, collagen synthesis, and angiogenesis. Cell tracking showed that the transplanted BM-MSCs appeared in skin structures, suggesting a direct contribution to skin regeneration. The paracrine secretion effect of BM-MSCs was also examined. The roles of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were studied, and EGF was found to play an important role in the skin regeneration-promoting effect of BM-MSCs. Conclusions: This study shows that BM-MSCs transplantation can shorten the tissue expansion process by enhancing skin regeneration.