A compatitive research on the application of bone marrow CD34+ stem cells vs. bone marrow mononuclear cells in small vascular endothelialization tissue engineering

Abstract

Objective To compare the application of bone marrow CD34+ stem cells vs.bone marrow mononuclear cells (MNCs) in vascular tissue prosthesis engineering.Methods We gathered dog bone marrow,segregated endothelia progenitor cells (EPCs) through immunomagnetic beads,and induced them to differentiate to endothelia cells (ECs) by endothelial cell growth facter(VEGF).Then we identified ECs through inverted phase contrast microscope,immunocytochemistry and tube-like structure formed test.Then we take some unfractioned MNCs,after routine cultivation implant them in the vascular prosthesis,and compare them under the microscope to the previous group.Results CD34+ cells being segregated were (78.46 ±6.37) ％ in content evaluated by flowcytometry,and were spread on the undersurface of culture flask 2 weeks after being cultured,and lined up as slabstones,being masccline for CD31 and Ⅷ factor in immunocytochemical staining.Under scanning eletron microscope,ECs tiled on the surface of vascular prosthesis,with their pseudopodia stretching out to micropore of vascular internalsurface; in the MNCs group no reticular structure can be readily found.For the CD34 cell group,the vascular prosthesis endothelialization area is (68.4 ±2.3)％,which is obviously more than that for the MNCs cell group (41.3 ±3.4) ％,P ＜ 0.01.Conclusion Highly purified bone marrow CD34+ cells can be obtained through immunomagnetic beads,cultured in vitro and differentiated to ECs directionally by VEGF.Better endothelialization effect can be gained from cell plantation on internal surface of vascular prosthesis than MNCs. Key words: Bone marrow; CD34+ cells ; Unfractioned Monocytes ; Vascular prosthesis ; Tissue engineering