Abstract:

Objective To prepare sodium alginate-nanohydroxyapatite composite material and to explore its feasibility as a bone repair material. Methods  Sodium alginate-nanohydroxyapatite composite material was prepared using chemical cross-linking and freeze-drying technology. The composite was characterized by X-ray diffraction (XRD) and scanning electron microscope(SEM)and its porosity wasmeasured byliquiddisplacement method.The fifth passage of bonemarrow stromal stem cells (BMSCs) were incubated on the composite material and then growth was observed by inverted micros-cope and SEM. BMSCs were cultured with liquid extracts of the material, methyl thiazolyl tetrazolium (MTT) assay was used to calculate the relative growth rate (RGR) on 1, 3, 5 d and to evaluate the cytotoxicity. Fresh dog blood was added into the liquidextractstoconducthemolysistest,thespectrophotometerwasusedtodeterminetheopticaldensity(OD)andtocalculate the hemolysis rate. Results Sodium alginate-nanohydroxyapatite composite material displayed porosity, the porous pore rate was (88.6±4.5)%. BMSCs showed full stretching and vigorous growth under inverted microscope and SEM. BMSCs cultured with liquid extracts of the material had good activities. The toxicity of composite material was graded as 1. Hemolysis test results showed that the hemolysis rate of the composite material was 1.28%, thus meeting the requirement of medical biomaterials. Conclusion  The composite material fabricated in
thisstudyhashighporosityandgoodbiocompatibility.

Key words: sodium alginate, nanohydroxyapatite, compositematerial, bonemarrowstromalstemcells, biocompatibility