Differentiation of cryopreserved bone marrow-derived mononuclear cells into endothelial progenitor cells

Objective:To compare the functions of endothelial progenitor cells(EPCs) differentiated from cryopreserved and fresh bone marrow-derived mononuclear cells(MNCs).Methods: The bone marrow samples were taken from swine iliac bones.The isolated MNCs were cultured or cryopreserved at-80℃ for 3 months and then cultured again.The P1-EPCs were identifed by Dil-ac-LDL and FITC-UEA-1 double staining,immunohistochemistry and flow cytometry.The EPC pick-up rate,migration,adhesion,and proliferation abilities were compared between the cryopreserved group and the fresh group.Results: Immunohistochemisty showed that the P1-EPCs of the cryopreserved group were positive for CD133(+),CD34(+),CD31() and KDR();flow cytometry also showed they were positive for CD133([17.24±3.12]%),CD34([37.21±10.85]%),CD31([72.07±13.34]%) and KDR([89.09±16.40]%).There were no significant differences in the pick-up rates([1.1±0.078]% vs [1.03±0.061]%,P=0.054),migration rates([15±0.71]% vs [14.2±0.63]%,P=0.17),adherence rates([42.7±2.1]% vs [39.5±1.7]%,P=0.11),and proliferation abilities([25.06±2.82]×104 vs [21.64±2.34]×104,P=0.089) between EPCs of the fresh and cryopreserved groups.Conclusion: Cryopreservation has no measurable influence on the numbers and functions of EPCs differentiated from bone marrow-derived MNCs,so cryopreservation can be used to obtain sufficient homogeneous EPCs in a short period for therapy using EPCs transplantation.