目的：研究负载γ-Fe2O3的壳聚糖多孔海绵对大鼠骨髓间充质干细胞（rat bone marrow mesenchymal stem cell，rBMSC）增殖和成骨分化的影响。方法：使用冻干-交联法制备负载γ-Fe2O3浓度分别为1%、5%、10%和20%的壳聚糖海绵，并制备空白对照组。将rBMSC培养于海绵上，通过扫描电镜和共聚焦显微镜观察细胞黏附及增殖情况，通过CCK-8法检测细胞第1、3、5和7天的增殖情况，通过碱性磷酸酶（alkaline phosphatases，ALP）染色及活性检测和荧光定量PCR检测第7和14天ALP活性和成骨指标碱性磷酸酶(Alp)、骨形态发生蛋白(bone morphogenetic protein 2，Bmp2)、胶原蛋白(collagen I，Col1) 和核心结合因子α1 (core binding factor alphal 1，Runx2)表达；使用茜素红定量法评估第21和28天细胞外基质矿化情况。结果：CCK-8结果显示rBMSC均能在材料上持续增殖，添加γ-Fe2O3的各组对rBMSC增殖有促进作用；ALP活性检测及染色结果和PCR结果显示γ-Fe2O3的添加能提高ALP活性并促进成骨指标表达；茜素红定量结果显示添加浓度为5%和10%的矿化物形成量高于对照组。（P < 0.05）结论：负载γ-Fe2O3的壳聚糖海绵能够促进rBMSC的增殖和早期成骨分化，浓度为5%和10%对rBMSC成骨分化晚期矿化物形成有促进作用。
Objective：To study the effects of γ-Fe2O3-loaded chitosan porous sponge on the proliferation and early osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs). Methods：Chitosan sponges loaded with γ-Fe2O3 at concentrations of 1%, 5%, 10% and 20% were prepared by freeze-drying and cross-linking, and blank control group was prepared. Scanning electron microscopy and confocal microscopy were used to evaluate the adhesion and proliferation of rBMSCs on the sponges. Cell proliferation at 1, 3, 5 and 7 days was detected by CCK?8. The early osteogenic differentiation of rBMSC at 7 and 14 days was evaluated by ALP staining and activity detection. Real-time fluorescence quantitative reverse transcription PCR was used to detect the expression of alkaline phosphatases (Alp), bone morphogenetic protein 2 (Bmp2), collagen I (Col1) and core binding factor alphal 1 (Runx2) after 7 and 14 days of osteogenic induction. The mineralization of extracellular matrix at 21 and 28 days was assessed by alizarin red staining quantitative method. Results：CCK?8 results showed each group added with γ-Fe2O3 promoted the proliferation of rBMSCs. ALP activity detection and staining results showed the addition of γ-Fe2O3 can improve the activity of ALP. The results of real-time fluorescence quantitative reverse transcription PCR showed that the addition of γ-Fe2O3 can promote the expression of osteogenic indexes Alp, Bmp2, Col1 and Runx2 . The quantitative detection results of alizarin red staining showed that the amount of mineralization in the groups of 5% and 10% was higher than that in the control group. (P < 0.05) Conclusion：The chitosan porous sponge loaded with γ-Fe2O3 promoted the proliferation and the early indicators of osteogenic differentiation of rBMSCs, and that at concentration of 5% and 10% can promote the formation of mineralization in the late stage of osteogenic differentiation of rBMSCs.