Isolation, culture and identification of mesenchymal stem cells from human umbilical cord as well as their osteogenic and adipogenic differentiation / 西安交通大学学报(医学版)

ABSTRACT

Objective To establish an optimized method to isolate, culture and identify human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro and induce their osteogenic and adipogenic differentiation. Methods The hUCMSCs were isolated from human umbilical cord by digestion with collagenase. After serial subcultivation in vitro, the stem cells were passaged. Morphologic appearance of hUCMSCs was observed under an optical microscope and atomic force microscope. The proliferation rate was measured by MTT assay. Cell cycle and surface antigens were measured by flow cytometry. The osteogenic and adipogenic differentiation was tested and evaluated by specific staining methods. Results The isolation of hUCMSCs by digestion with collagenase was efficient. After seeded for 24 hours, the adherent cells showed spindle shape and fibroblast cell-like shape and the size of hUCMSCs was homogeneous. The similar growth curves of passage 3 and 7 exhibited a great potential for proliferation. Flow cytometry analysis revealed that CD29, CD44 and CD105 were highly expressed on the surface of passages 3 cells, but the expression was negative for CD34, CD45 and HLA-DR. After culture in inducing medium, the cells were successfully induced into osteogenic and adipogenic lineages. These cells were highly positive for alkaline phosphate staining and also showed mineralization presented with von kossa staining after 4 weeks' culture induction of osteogenic differentiation. Furthermore, liquid vacuoles were detected by oil red O staining after 3 weeks' culture induction of adipogenic differentiation. Conclusion An in vitro method for isolation and purification of hUCMSCs from human umbilical cord has been established. The cultured cells were composed of only undifferentiated cells and their biological properties were stable. The hUCMSCs are expected to be a new type of stem cells of tissue engineering.