In vitro culture and biological characteristics of human bone marrow-derived endothelial progenitor cells

AIM: To purify and culture human bone marrow-derived endothelial progenitor cells (EPCs) in vitro and to observe their biological characteristics. METHODS: Mononuclear cells were isolated from bone marrow suspension by density gradient centrifugation and EPCs were harvested in the endothelial growth medium (EGM-2). EPCs were observed under microscope, the cell growth was calculated by cell counting and the cells were identified by electronic microscope examination and immunofluorescence staining for the expression of Ⅷ/vWF, vascular endothelial growth factor receptor-2 (VEGFR-2). RESULTS: The culture-dish-adherent EPCs uniformly had a round or spindle shape and reformed clones with cobble-stone morphology. The cells could be identified by the positive staining for VEGFR-2 and Ⅷ/vWF. Weibel-Paladle bodies could be seen under transmission electron microscope. CONCLUSION: EPCs are one group of stem cells in the bone marrow with the capacity of differentiating into endothelial cells. They can be purified and cultured by density gradient centrifugation and subjected to culture in vitro with endothelial growth medium (EGM-2 MV). These findings suggest that EPCs may be a new seed cell of tissue engineering.