Isolation,proliferation,and osteoblast and lipoblast differentiation of human umbilical cord blood mesenchymal stem cells

Xin TIAN; Liuping TANG; Ping XIAO; Renyi FU; Tianzhu YUAN; Hong CHEN

ABSTRACT

BACKGROUND:

Compared with bone marrow-derived mesenchymal stem cells (MSCs),human umbilical cord blood (hUCB)-MSCs possess many advantages,including easy acquirement,low immunogenicity,able to tolerance a higher degree of HLA-matching inconsistency,and with higher purity.

OBJECTIVE:

To analyze the method and condition for in vitro isolation,purification,proliferation,and osteoblast and lipoblast differentiation of hUCB-MSCs.DESIGN,TIME AND

SETTING:

The present observational experiment was performed in the Key National Laboratory of Biological Treatment,Huaxi Hospital,Sichuan University (i.e.,Institute of Stem Cells and Tissue EngIneering) between September 2004 and November 2005.MATERIALS Neonatal cord blood at gestational age 37 to 40 weeks.

METHODS:

hUCB-MSCs were collected in aseptic condition,isolated by density gradient centrifugation,sedimenting red cells with methylcellulose followed by density gradient centrifugation,or immunomagnetic beads negative technique of CD34+.Theisolated MSCs were used to carry on plastic adherent culture in L-DMEM +10% fetal bovine serum (FBS) or MesencultTM medium +10% FBS.The third passage of cells were used for surface antigen determination by flow cytometry and induced to differentiate towards osteoblasts and lipoblasts.MAIN OUTCOME

MEASURES:

①Identification of hUCB-MSCs.②Confirmation of hUCB-MSC differentiation by alizarin red and oil red staining.

RESULTS:

The mononuclear cells isolated by sedimented and centrifuged way cultured in MesencultTM medium +10% FBS were most available.Obvious colonies appeared in the third passage.The cells obtained by only centrifugation in density gradient were hard to form colony,and those isolated by immunomagnetic beads were hard to culture.The surface antigens of these colony cells presented CD29,CD59,and CD71,hut did not express CD34,CD45,and HLA-DR,and so on.After alizarin red staining,osteoblast-differentiating colony cell cytoplasm exhibited mineralized matrices.After old red staining,lipoblast-differentiating colony cell cytoplasm was full of lipid vacuoles.

CONCLUSION:

The MSCs can be successfully isolated by sedimenting red cells with methylcellulose followed by centrifugation and cultured in MesencultTM medium +10% FBS.Obvious colony growth appears in the third passage.After induction,the MSCs can differentiate into osteoblasts and lipoblasts.