The Effect Of Low Intensity Pulsed Ultrasound On Biological Behaviors Of BMSCs On Titanium With Different Surface Topography

Objective To observe the biological behaviors effect of low intensity pulsed ultrasound(LIPUS)on the osteogenic differentiation of rats’ bone marrow mesenchymal stem cells(BMSCs)on the surface of titanium.Methods BMSCs,derived from bone marrow of Wistar rats,were seeded on the flat titanium surface and the large grain blast acid etched(SLA)titanium surface,and were detected the proliferation activity of the cells by CCK8 after ultrasonic stimulation;cell growth in titanium surface was observed by scanning electron microscope;The expression of vinculin was detected by immunofluorescence technique.The cells were seeded on the surface of titanium and mineralized induced,and then stimulated by ultrasound,Alkaline phosphatase(ALP)were quantitative determinated after 3 days ’ and 7 days ’ induced mineralization respectively,while ALP staining were observed after 14 d.Alizarin red staining were observed after 21 days’ mineralization induction.Bone related protein and osteogenic related gene expressions were detected after mineralization induction.Results The proliferation activity was detected with CCK8 after ultrasonic stimulation,ultrasound group has increased proliferative activity,cell growth more filopodia,expression of vinculin was higher than the control group.ALP in culture medium of LIPUS group was higher than that of the control group after 3days’ and 7 days’ induced mineralization(P<0.05).In the ALP staining and alizarin red staining experiments,the staining of the LIPUS group ware deeper and more mineralized nodules were formed.Osteogenic related genes expression,including ALP,Runx2,BMP2,OPN,OCN and COL1 of the LIPUS group increased to some extent.The expression of osteogenic related proteins,including Runx2,BMP2,OPN in LIPUS group increased.Conclusion The proliferation,adhesion and osteogenic differentiation of BMSCs on flat and SLA titanium surface can be promoted by LIPUS.