骨形态发生蛋白-聚乙烯砒洛啉酮-纳米晶胶原基骨缓释系统与骨髓间充质干细胞的生物相容性

背景:骨形态发生蛋白在骨组织工程中很易降解,聚乙烯吡咯啉酮理论上存在与骨形态发生蛋白结合并对其缓释的作用。目的:观察聚乙稀吡咯啉酮修饰的纳米晶胶原基骨复合骨形态发生蛋白的体外缓释效果,并与成骨细胞复合培养,以期得到一种生物相容性较为理想的缓释支架系统。方法:实验分为3组,即聚乙烯吡咯啉酮修饰的骨形态发生蛋白复合纳米晶胶原基骨组、骨形态发生蛋白复合纳米晶胶原基骨组及聚乙烯吡咯啉酮修饰的骨形态发生蛋白复合大鼠松质骨组。以ELISA法检测3种复合物的骨形态发生蛋白体外释放活性。将SD大鼠骨髓间充质干细胞分离后定向诱导为成骨细胞并种于支架上,3,7,10,14d时检测支架中的细胞计数;细胞培养14d后采用扫描电镜观察细胞生长情况。结果与结论:骨形态发生蛋白体外释放曲线可见14d后实验组上清液中骨形态发生蛋白仍保持较高的浓度。培养14d后,大鼠骨髓间充质干细胞Ⅰ型胶原免疫荧光染色阳性,支架中脱落细胞计数均高于对照组(P<0.05)。扫描电镜结果发现实验组支架上的细胞生长情况明显好于对照组。提示聚乙烯吡咯烷酮修饰的纳米晶胶原基骨支架具有良好的缓释骨形态发生蛋白的作用,与大鼠骨髓间充质干细胞有很好的生物相容性。

Biocompatibility of bone marrow mesenchymal stem cells and bone morphogenetic protein-polyethlenepyrolindone-nano hydroxyapatite/collagen delayed release system

BACKGROUND：Bone morphogenetic protein （BMP） is important in bone tissue engineering and it is easily degraded by protainases in the body. According to the related researches, polyethlenepyrolindone （PVP） can effectively make BMP to releases lower and has good biocompatibility with the stent. OBJECTIVE：To study the effect of the delayed release system of PVP modified nano-hydroxyapatite, then to cultivate it with bone marrow mesenchymal stem cells （BMSCs） that have been induced to osteoblasts to prepare a new delayed release system with good biocompatibility. METHODS：The samples were divided into three groups：PVP modified BMP combined with nano-hydroxyapatite; unmodified BMP combined with nano-hydroxyapatite; PVP modified BMP combined with spongy bone from SD rat bone marrows. First, the activity of PVP-BMP microsphere was detected by ELISA. Second, after the BMSCs were induced and proliferated to osteoblasts, they were seeded onto the scaffold. The number of cells on the scaffold was counted at different time points （3, 7, 10, 14 days）. The cell growth on scaffold was also observed by scanning electron microscope 14 days later. RESULTS AND CONCLUSION：The expression of BMP was still higher after 14 days in the experimental group. The differentiation of BMSCs to osteoblastic phenotype was demonstrated by the positive staining of collagen type Ⅰ. The cast-off cells from the scaffold in the experimental group were obviously more than those in the control group （P 0.05）. Scanning electron microscope observed that the cell grew better in the experimental group than in the control group. PVP-modified BMP-nanohydroxyapatite delayed release system has good effect, it can cause BMSCs to proliferate and differentiate well.