No abstract

Hydroxyapatite (HA) powders containing differentconcentrations of astragalus polysaccharides (APS) were synthesized by a wetchemical method. The effect of APS on the crystal structure, crystallinity andcrystal size of HA was characterized by XRD, the crystal morphologies of HA and HA/APS were characterized by TEM, the particle sizeand specific surface area of HA were detected by laser partical size distributionanalyzer, automated surface area and pore size analyzer, respectively. Furthermore,the effective concentration of APS on MC3T3―E1 osteoblasts, HA/APS onosteoblastic activity and differentiation was evaluated by Alamar blue, MTT andalkaline phosphatase assay. Cell morphologe was observed by light microscope.The results showed that the crystal structure, crystallinity andcrystal size of HA were not obviously effected by the presence of APS. Crystal morphologies of HA/APS was almost the samecompared with HA, the average particle size of HA was 1.17 μm and specificsurface area was 132.194 m²/g. The effect of APS on osteoblasts wastime and dose―dependent, APS concentrations within 80―200 μg/mL enhanced osteoblastic activity and ALPexpression, HA/APS enhanced osteoblastic activity and the osteoblasts hadintegrated morphology. It can be concluded that 0.5 g of HA containing 100―250 μm APS can promote osteoblastic activity. HA/APShas the promising potential as bone defect filling material for clinical applications