In Vivo Vascularization of Endothelial Cells Derived from Bone Marrow Mesenchymal Stem Cells in SCID Mouse Model

OBJECTIVE In vivo and in vitro stem cell differentiation into endothelial cells is a promising area of research for tissue engineering and cell therapy. MATERIALS AND METHODS We induced human mesenchymal stem cells (MSCs) to differentiate to endothelial cells that had the ability to form capillaries on an extracellular matrix (ECM) gel. Thereafter, the differentiated endothelial cells at early stage were characterized by expression of specific markers such as von Willebrand factor (vWF), vascular endothelial growth factor (VEGF) receptor 2, and CD31. In this experimental model, the endothelial cells were transplanted into the groins of severe combined immunodeficiency (SCID) mice. After 30 days, we obtained tissue biopsies from the transplantation sites. Biopsies were processed for histopathological and double immunohistochemistry (DIHC) staining. RESULTS Endothelial cells at the early stage of differentiation expressed endothelial markers. Hematoxylin and eosin (H&E) staining, in addition to DIHC demonstrated homing of the endothelial cells that underwent vascularization in the injected site. CONCLUSION The data clearly showed that endothelial cells at the early stage of differentiation underwent neovascularization in vivo in SCID mice. Endothelial cells at their early stage of differentiation have been proven to be efficient for treatment of diseases with impaired vasculogenesis.