中文摘要：

目的制备海藻酸钙．纳米羟磷灰石复合材料，探讨其作为骨修复材料的可行性。方法应用化学交联及冷冻干燥技术制备海藻酸钙一纳米羟磷灰石复合材料，通过扫描电镜（SEM）和X光衍射（XRD）对材料性能进行表征，液体置换法测定孔隙率。将第5代骨髓基质于细胞（BMSCs）接种至材料上，倒置显微镜及SEM观察细胞生长情况。材料浸提液与BMSCs共培养，甲基噻唑基四唑（MTT）法检测接种后1、3、5dN相对增殖率（RGR），并评估毒性分级。新鲜犬血加入材料浸提液进行溶血试验，分光光度计测定光密度值并计算溶血率。结果制备的海藻酸钙．纳米羟磷灰石复合材料具有多孔性，孔隙率达（88．6±4．5）％。倒置显微镜及SEM观察可见，细胞在材料周围及表面伸展充分、生长旺盛。材料浸提液培养的细胞具有较好的活力，其毒性分级为1级。溶血试验结果表明复合材料的溶血率为1．28％，满足医用生物材料的要求。结论本研究制备的复合材料具有较高的孔隙率和良好的生物相容性。

英文摘要：

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 was measured by liquid displacement method. The fifth passage of bone marrow stromal stern 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 liquid extracts to conduct hemolysis test, the spectrophotometer was used to determine the optical density （OD） and to calculate 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 this study has high porosity and good biocompatibility.