A Study on the Effect of Biologic Activity by Bone Marrow Stromal Cells with Different Seeding Density in Vitro

Objective To evaluate the effect on the osteogenic potential of bone marrow stromal cells (BMSCs) with different initial seeding density in vitro.Methods BMSCs isolated from Beagle were cultured--expanded,subcultured.The different density of the first passage (P1) BMSCs suspensions were prepared at 5×10~7 cells/mL,5×10~6 cells/mL or 5×10~5 cells/mL. BMSCs in different suspensions were plated into 60 mm dishes,the formation process of mineral nodules was observed with microscope.The alkaline phosphatase (ALP) activity of BMSCs which combined with collagen membranes in different density were detected and compared on 2~(nd) day,5~(th) day and 7~(th) day.Results Higher density resulted in better mineralized tissue formation early.In these complex,higher ALP activity were detected following the culture days at the same density.The ALP activity were significant different in the 5×10~5 cells/mL,5×10~6 cells/mL and 5×10~7 eells/mL groups at the same day,but there was no significant different between the first two groups.Conclusion The osteogenic capacity of BMSCs has cell density dependent.The higher concentrations resulted in the stronger activity of osteogenic potentiality in vitro.