Isolation of mesenchymal stem cells derived from umbilical cord by serum free culture medium

Objective To identify the isolated and purified mesenchymal stem cells(UC-MSCs) derived from umbilical cord by serum free culture medium in vitro in order to know more about its role in osteogenesis which may provide basic data for applying potentially clinical treatment in the future.Methods Nubbles of umbilical cord tissue were cultured with serum free culture medium.UC-MSCs were observed under an inverted microscope.Grown UC-MSCs were isolated and purified from umbilical cord tissue cultures without any serum.UC-MSCs' markers CD34、CD44、CD90 and CD45 were detected by flow cytometry.The cells were induced by bone induction culture medium for 2～3 weeks and then differentiated to osteoblast-like cells.The morphological changes on cell surface were monitored during cell differentiation,and osteoblast-like cells were further confirmed by alizarin red staining.Results A small amount of spindle cells were found to scrawl out from umbilical cord tissue blocks after having been cultured in serum free medium for 12 hours.A monolayer of cells was confluent on the plates on 5-6th day,and then stratified into multi-layers after 12th day.The cell surface markers were positive for CD44,CD90,and negative for CD34,CD45 indicating that the cells were originally from mesenchymal stem cells but not from hematopoietic ones.UC-MSCs had been differentiated into osteoblast-like cells after osteoblast induction for 2-3 weeks.Conclusion Using human mesenchymal stem cell-specific medium culture system without any serum,a large amount of UC-MSCs can effectively be isolated and harvested.The cells can be induced into osteoblasts and avoid any heterogeneous proteins interfusion so as to reduce clinical applications.