Differentiation of Human Umbilical Cord Blood-Derived CD34+ Cells into Endothelial Cell on Silk Fibroin Film

Objective: To evaluate the feasibility of isolating,purifying and expanding of umbilical cord blood-derived CD34(+) cells in vitro and the way to induce them into endothelial cells(ECs),and explor the effect of the regenerated silk fibroin film to the CD34(+) cells-derived Ecs'growth,adherence and differentiation.Methods: CD34(+) mononuclear cells were selected by magnetic beads coated with antibody CD34.Cells were transferred onto regenerated silk fibroin film(SF) and gelatin coated dishes, and cultured in M-199 medium containing vascular endothelium growth factors(VEGF) and basic fibroblast growth factors(bFGF),then identify the adherence and proportion of the CD34(+) cells-derived Ecs under these two substrates.Results: The number of CD34(+) cells on SF and gelatin reached to the highest level at the 14th d;In FACS assay, (75.53 +/- 4.89) %and (74.59 +/- 3.58) % of CD34(+) cells were positive-stained for CD31 respectively on SF and gelatin after 10 days of differentiation,tne expression of vWF in the cells were both approximately 80% after 14 days of differentiation under these two substrates; The endothelial-specific Weibel-Palade body were both detected in the cytoplasm by electronic microscope;The CD34(+) cells adhered to the gelatin and SF were both fast, and the differentiate rate were both approximately 80% under these two substrates,had no obviously disparity.Conclusion: Human umbilical cord blood-derived CD34(+) cells may be induced to differentiate into endothelial cells induced by VEGF and bFGF,and silk fibroin materials can be used as scaffolds.So we can get tissue engineering prosthesis with the ability of forming capillary network in the shortest time to maintain the living of parenchymal cells.