Effect Of New Composite Bone Materials Alendronate-Chttosan- Hydroxyapattte In Promoting Bmscs Proliferation

Objective:By using a kind of new composite scaffold materials alendronate-hydroxyapatite-chitosan, this study intend to detect the effect on proliferation of bone marrow-derived mesenchymal stem cells (BMSCs).Methods:By employing the new composite scaffold materials, we test its effect on BMSCs proliferation. We set up the control group use materials with chitosan-hydroxyapatite composite; and the experimental group with alendronate-chitosan-hydroxyapatite composite. Following tests were conducted:rabbit bone marrow mesenchymal stem cells (BMSCs) were primary cultured and sub-cultured. The third passage of bone marrow mesenchymal stem cells and scaffolds were co-cultured and examined by scanning electron microscopy, and the effect of composite materials to bone marrow mesenchymal stem cells proliferation was detected according to MTT. Bone marrow mesenchymal stem cells and composite materials were co-cultured with osteogenesis medium. At the day 14, the cells were eluted and seeded for alkaline phosphatase staining. The supernatant was collected for testing alkaline phosphatase activity at the day 3,7,14 after osteogenic culture. The cells were eluted and seeded for stretch alizarin red staining at the day 21 after osteogenic culture. The supernatant was collected and analyzed for BGP protein according to ELASA at the day 7,14,21 after osteogenic culture. The coll-Ⅰ protein was detected at the day 3,7,14 of osteogenic culture.Results:With the detection of scanning electron microscope, rabbit bone marrow mesenchymal stem cells cultured on composite scaffold showed irregular shape, cell spreading and adhesion scaffold surface. No significant differences were observed between the experimental group and the control group. MTT assay showed that the proliferation rate of bone marrow mesenchymal stem cells on alendronate-hydroxyapatite-chitosan scaffold was significantly higher than that on hydroxyapatite-chitosan composite (P<0.05). The ALP positive staining was detected in the experimental group and this staining was significantly stronger than that in the control group at the day 14 of osteogenic culture. ALP activity in the experimental group were significantly higher than that in the control at the day 3,7,14 of osteogenic culture (P<0.05). At the day 21 of osteogenic culture, the alizarin red positive staining in the experimental group was significantly higher than that in the control group (P<0.05). There was no significant difference on the accounts of BGP secretion between the experimental group and the control group at the day 7 of ostegenic culture. At the day 14 and 21, the accounts of BGP secretion was significantly higher in experimental group than that in the control group (P<0.05). At the day 3,7,14, the coll-Ⅰ protein secretion was significantly higher in experimental group than that in the control group (P<0.05).Conclusion:(1) The new alendronate-chitosan hydroxyapatite composite scaffold materials can effectively promote bone marrow mesenchymal stem cells proliferation and osteogenic differentiation. (2) The new chitosan-hydroxyapatite composite scaffold materials could be an ideal bone repair material for tissue engineering.