Objective: To examine the effects of alginate on bone mesenchymal stem cells(bMSCs).Methods: bMSCs were cultured on the alginate gels(experimental group) and tissue culture plastics(control group);the morphous of bMSCs was observed by microscope after toluidine blue staining;the growth curves were analyzed by MTT;and the expressions of osteoblast related genes(alkaline phosphatase

collagen I and osteonectin) were detected by RT-PCR when cultured for 6 days.Results: There were no difference in the cell proliferation between the experimental group and control group.The morphous of bMSCs in the experimental group was induced to be similar to that of osteoblasts and form colony proliferation obviously.The alkaline phosphatase and collagen I genes were positive in the two groups

but their expressions in the experimental group were higher;at the same time

osteonectin gene was positive in the experimental group and negative in the control group.Conclusion: bMSCs may differentiate into osteoblasts automatically when cultured for longer time and that alginate gels could promote this differentiation and may be suitable biomaterial of scaffold in bone tissue engineering.