新型壳聚糖基仿生网络复合膜诱导骨髓间充质干细胞定向成骨分化

Osteogenic differentiation behaviors of mesenehymal stem cells on chitosan based network composites films

目的 探讨新型壳聚糖基网络复合膜诱导骨髓间充质干细胞（MSCs）定向成骨分化的可行性.方法 采用仿生学方法,壳聚糖、明胶、果胶按照一定比例制作成新型壳聚糖基仿生网络复合膜.设计4个组：实验组1（复合膜＋常规培养基）,对照组1（常规培养基）,实验组2（复合膜＋成骨诱导（OS）培养基）,对照组2（OS培养基）.通过倒置相差显微镜、四甲基偶氮唑盐（MTT）法、扫描电镜（SEM）检测细胞在复合膜上的生长和增殖情况;通过测定碱性磷酸酶（ALP）活性来评价MSCs在复合膜上的成骨分化能力;通过特殊染色和能谱分析（EDX）来评定钙盐的沉积.结果 MSCs在网络复合膜上贴附、生长良好且增殖旺盛.MTr法检测细胞活力显示实验组吸光度（OD）值与对照组比较无统计学意义（P＞0.05）.SEM观察到细胞在支架材料表面呈聚集生长,分泌大量的细胞外基质,可见散在的结节形成.实验组1的ALP活性明显增高,与实验组2、对照组比较有统计学意义（P＜0.01）.茜素红和Von Kossa染色可见实验组细胞分化后形成的钙化结节;ALP染色可见胞浆内蓝染颗粒;EDX检测到Ca、P沉积.结论 新型壳聚糖基网络复合材料具有良好的生物相容性,在不添加诱导剂的条件下,可以诱导MSCs定向成骨分化.

Objective To study the osteogenic differentiation capacity of mesenchymal stem cells（MSCs）on chitosan based biomimetic network composites films.Methods The chitosan-based biomimetic network composites films were prepared using chitosan,gelatin and pectin in certain ratio by biomimetic approach.The experiment was designed as follow：experimental group 1 （composites films＋routine medium）,control group 1 （routine medium）,experimental group 2（composites films＋osteogenic medium）,control group 2（osteogenic medium）.The growth and proliferation of MSCs were observed by inverted phase contrast microscope and scanning electronmicroscopy（SEM） and detected through methyl thiazolyl tetrazolium（MTT） assay.Alkaline phosphatase（ALP） activity was used to investigate the osteogenic differentiation capacity.The formation of mineral was determined by special staining and the energy dispersive X-ray apparatus （EDX）.Results MSCs could well adhere,grow and proliferate on the network composites films.The MTT assay demonstrated that there was no significant difference in cell viability between the experimental and control groups （P〉0.05）.SEM observation showed that MSCs grew assembly on the surface of the films secreted a large number of extracelluar matrix,and formed scattered nodules.The cells on the experimental group 1 showed statistically higher ALP activity level than those cells on the other groups （P〈0.01）.Moreover,the calcified nodules can be seen in the experimental groups by Alizarin red and Von Kossa staining.ALP staining showed blue-staining granules within the cytoplasm,and the deposition of Ca and P was detected on the films by SEM-EDX.Conclusion The novel chitosan-based biomimetic network composites films not only have good biocompatibility,but can also improve MSCs differentiation toward the osteogenic lineage.