Comparative Study On The Capacity Of Rat Dental Pulp Stem Cells And Bone Marrow Mesenchymal Stem Cells In Differentiating To Osteoblast-like Cells

Comparative study on the capacity of rat dental pulp stem cells and bone marrow mesenchymal stem cells in differentiating to osteoblast-like cellsObjective research on extraction of rat dental pulp stem cells (DPSCs) and bone marrow mesenchymal stem cells (BMSCs). To take observation of the differences in their morphology and growth curve. Staining to distinguish the stem cell's marker expression.Inducing DPSCs and BMSCs in differentiating to osteoblast-like cells. Taking observation of the expression of markers on osteoblast after inducing and the ability of bone-formation. Taking discussion of characteristics of rat dental pulp stem cells on differentiating to osteoblast-like cells.Methods Rat bone marrow mesenchymal stem cells were obtained by centrifugation, the whole one marrow was cultivated in DMEM medium, taking morphologic observation by inverted microscope. Dental pulp stem cells were obtained by enzymatic digestion, takeing morphologic observation after proliferation in vitro. Scaning CD45 and CD90 expression on cells by flow cytometry (FCM), detecting the expression of STRO-1 by immunofluorescence growth curves of BMSCs and DPSCs were measured by MTT, taking comparison of cell growth. Both of DPSCs and BMSCs were induced to osteoblast-like cells The expression of OCN and DSP on cells were detected by immunofluorescence after 2-weeks-induction. calcific nodules which were secreted by DPSCs were stained by alizarin red after 4-weeks-inductionResults BMSCs obtained by centrifugation was purified after adhered cultivation, hematopoietic cells were removed gradually. DPSCs obtained by enzymatic digestion can be completely adherent in the second day and proliferated vigorously. Cells exhibited a negative expression of CD45 and a positive expression of CD90 which consisted with the characteristics of mesenchymal stem cells. The positive STRO-1 expression in inmmunofluorescence fitted with stem cells'feature. Growth curve shows that both DPSCs and BMSCs went into logarithmic phase in the fourth day. DPSCs had a higher proliferation than BMSCs. After 2-weeks-induction, both DPSCs and BMSCs express a positive OCN molecule, and the DSP expression was positive on DPSCs. The formation of calcific nodules could be proved by alizarin red staining at the bottle of DPSCs medium after 4-weeks-induction.Conclusions BMSCs obtained by centrifugation could be purified by the whole bone marrow cells adhered cultivation, hematopoietic cells were removed by medium changes. The purity of BMSCs which was detected by FCM could be higher than 80% in P2. DPSCs obtained by enzymatic digestion consisted with the characteristics of mesenchymal stem cells and perform a higher proliferation ability. After mineralized induction, DPSCs differentiate into osteoblast-like cells just like BMSCs in the molecule expression, there were also calcific nodules at the bottle of DPSCs'medium. It means that both the proliferation ability and differentiation ability into osteoblast-like cells of DPSCs were brilliant, which offers a ideal cells for repairation of bone defect.