【摘要】 背景:骨形态发生蛋白2在骨形成及修复过程中起着至关重要的作用,但存在易流失、易降解、难以持续作用等缺点。目的:探讨缓释骨形态发生蛋白2丝素蛋白/壳聚糖/纳米羟基磷灰石生物支架的制备方法及性能。方法:将蚕丝脱胶、溶解并提纯得到2%丝素蛋白溶液,将骨形态发生蛋白2溶于2%壳聚糖溶液中,搅拌均匀后与等体积丝素蛋白溶液和适量纳米羟基磷灰石充分混合,采用冷冻干燥法制备成缓释骨形态发生蛋白2的丝素蛋白/壳聚糖/纳米羟基磷灰石生物生物支架,作为实验组;以相同浓度骨形态发生蛋白2浸泡丝素蛋白/壳聚糖/纳米羟基磷灰石支架材料,作为对照组;采用阿基米德法测定两组支架的孔隙率,扫描电子显微镜观察两组支架表面形貌,万能测试机测试两组支架的抗压强度。将两组支架分别浸泡于PBS中,与不同的时间点采用ELISA法检测骨形态发生蛋白2的释放量。结果与结论:(1)两组支架为不规则多孔结构,孔间相通,孔壁凹凸不平,两组支架平均孔径、孔隙率及最大抗压强度比较差异无显著性意义;(2)实验组第1天的骨形态发生蛋白2释放量为4.63%,释放曲线缓慢上升,第28天之后释放曲线转入平台期;对照组第1天的骨形态发生蛋白2释放量高达58.84%,呈显著的初始爆发释放,并迅速上升,在第10天之后释放曲线转入平台期。两组第1,2,4,10天的骨形态发生蛋白2释放量比较差异有显著性意义(P<0.05);(3)结果表明,缓释骨形态发生蛋白2的丝素蛋白/壳聚糖/纳米羟基磷灰石生物支架可持续缓慢释放骨形态发生蛋白2。更多还原

【Abstract】 BACKGROUND: Bone morphogenetic protein-2（BMP-2） is a key to bone formation and repair. However, it has some disadvantages such as easy to lose and degrade and difficult to sustain continuous effect. OBJECTIVE: To study the preparation and properties of silk fibroin/chitosan/nano-hydroxyapatite（SF/CS/n HA） scaffold loading BMP-2. METHODS: After silk degumming, dissolution and purification, 2% SF solution was obtained. BMP-2 was dissolved in 2% CS solution, and then fully mixed with equal volume of SF solution and proper amount of n HA. At last, the SF/CS/n HA scaffold loading BMP-2 was prepared using freeze-drying method as experimental group. The SF/CS/n HA scaffold was soaked in the BMP-2 solution as control group. The scaffold porosity was measured by Archimedes method, the surface morphology of the scaffold was observed by scanning electron microscope, the compressive strength was measured by universal testing machine. Scaffolds in the two groups were soaked in PBS, and the release of BMP-2 was measured by ELISA method at different time points. RESULTS AND CONCLUSION:（1） The scaffolds in the two groups had irregular porous structure, interconnected pores and uneven pore wall. There was no significant difference between the two groups in mean pore diameter, porosity and maximum compressive strength.（2） On the 1^st day, the release rate of BMP-2 was 4.63% in the experimental group, and the release curve increased slowly. After 28 days, the release curve of BMP-2 was transferred to the plateau stage. But in the control group, the release rate of BMP-2 on the 1^st day was 58.84%, and it was a significant initial burst release. The release curve increased rapidly, and was transferred to the platform stage on the 10^th day. The release rate of BMP-2 release was significantly different between the two groups at days 1, 2, 4, 10（P < 0.05）. These results show that the SF/CS/n HA scaffold loading BMP-2 could sustainably and slowly release BMP-2.更多还原