[Experimental research using human bone marrow mesenchymal stem cells as the seed cells for bone and cartilage tissue...

To investigate the feasibility of human bone marrow mesenchymal stem cells(hMSCs) as the seed cells for bone and cartilage tissue engineering.

Purified hMSCs were cultured in-vitro and induced to differentiate into osteoblasts and chondrocytes. Cellular morphologies were observed under inverted and electron microscopes. The specific markers of the osteoblasts and chondrocytes were detected by histochemical staining, immunohistochemical staining, and RT-PCR.

After the hMSCs were passaged for 15 generations, the choractenistic morphology and cell surface antigens of hMSCs remained unchanged. The level of alkaline phosphatase(ALP) in the culture supernatant of the osteoinduction groups was higher than those in the control groups (P<0.05). The morphology of the cells in the osteoinduction and chondroinduction groups changed from spindle-shaped cells into polygon-shaped cells. A large number of the dilated rough endoplasmic reticulua, Golgi apparatus and mitochondria could be seen under transmission electron microscope. Calcium deposition was detected on the surfaces of the hMSCs after osteoinduction. Collagen(COL)-like processes were detected under scanning electron microscope. The staining of the ALP, calcium nudis, COL-I and osteocalcin(OC) were positive, and expressions of the COL-I and OC mRNAs were detected after osteoinduction. The expression of COL-II was detected by immunohistochemical staining and RT-PCR and a lot of the metachromatic-staining matrix around the cells was observed with toluidine blue staining after chondroinduction.

hMSCs from human bone marrow can be purified, expanded and differentiated into osteoblasts and chondrocytes in-vitro, providing an alternative source for bone and cartilage tissue engineering.