Induction of differentiation of CD34+ cells in vitro and application in endothelialization of blood vessel prostheses

Abstract

To induce differentiation of CD(34)+ cells from varying sources into epithelial cells for potential application of blood vessel prostheses. CD(34)+ cells were isolated from canine peripheral blood and bone marrow or human umbilical cord blood by an immune magnetic cell sorting system. The isolated CD(34)+ cells were induced to differentiate into endothelial cells in a liquid culture with VEGF. Endothelial cells were evaluated by immunocytochemistry and transmission electron microscopy. CD(34)+ cells were seeded on PTFE prostheses, which were harvested and observed by electron microscopy. The average isolated CD(34)+ cells from peripheral blood, bone marrow and umbilical cord blood were (26.30+/-2.42)%,(41.84 +/-3.65)%and (74.62+/-4.46)%, respectively. The number of CD(34)+ cells increased with the culture duration and reached to the highest level at the 14th d. Immunostaining showed positive signal for CD31 in endothelial cells and positive for factor VIII in cell culture. Transmission electron microscopy found Weibel-Palade bodies in the cytoplasm. Scanning electron microscopy demonstrated a single- layer of flat cells in the innermost layer of PTFE prostheses, and the cells were not of tropism. CD(34)+ cells isolated from peripheral blood, bone marrow and umbilical cord blood can be induced into endothelial cells; bone marrow and umbilical cord blood can be used as the sources of seeding cells for endothelialization of prostheses.