BACKGROUND:Adjustable piezoelectric effect can promote tissue regeneration and repair.Piezoelectric materials are widely used in weight-bearing tissue engineering. OBJECTIVE:To prepare a piezoelectric film material that can promote bone regeneration,and to explore its structural characterization,electrical output performance,biocompatibility,and effect of electrical output on osteogenic differentiation of rabbit bone marrow mesenchymal stem cells. METHODS:Using poly-3-hydroxybutyrateco/4-hydroxybutyrate(P34HB)as raw material,barium calcium stannate titanate powder(Ba0.94Ca0.06Sn0.08Ti0.92O3,BCST)was added according to mass ratios of 0%,5%,10%,15%,and 20%.Dichloromethane was added to solve P34HB,and the thickness of 150-200 μm BCST/P34HB piezoelectric film was prepared by vacuum drying method.After polarization in the oil bath,the surface morphology,crystal phase composition,piezoelectric coefficient and open circuit voltage were tested.The effect of BCST/P34HB electrical output at 110 Hz and 0.25 N force on the proliferation and osteogenic differentiation of rabbit bone marrow mesenchymal stem cells was tested. RESULTS AND CONCLUSION:(1)Scanning electron microscopy,X-ray diffraction,water contact angle,piezoelectric coefficient and electrical output performance tests showed that when the mass ratio of BCST increased to 20%,the BCST/P34HB piezoelectric film had good piezoelectric properties(d33=5.9 pC/N)and electrical output performance(180 mV),which was closer to the suitable range of 500 mV for electrical stimulation.(2)Live and dead staining showed that on the first day of co-culture,15%group and 20%group showed less red fluorescence.On the 5th day of culture,the number of green fluorescence in each group was significantly higher than that on the first day,and the red fluorescence was not observed in the 10%,15%and 20%groups,and only a small amount of red fluorescence was observed in the 0%and 5%groups.(3)On the 1st,3rd and 5th days of co-culture with rabbit bone marrow mesenchymal stem cells,Almar blue staining exhibited that the number of cells in each group showed an increasing trend with the increase of time.On the 5th day of culture,the number of cells in the 20%group was significantly more than that in the 0%group(P<0.05).(4)On day 10 of osteogenic induction,alkaline phosphatase staining results showed that the positive rate of the 20%group was significantly higher than that of the 0%group(P=0.000 1).On day 21,alizarin red staining and quantitative analysis of calcium nodules showed a similar trend to alkaline phosphatase staining.Compared with the 0%group,the 15%group and 20%group showed significant differences(P<0.01,P<0.000 1).(5)The results showed that 20%BCST/P34HB films had good piezoelectric properties,electrical output properties,biocompatibility and the ability of promoting osteogenic differentiation of bone marrow mesenchymal stem cells.