rh-BMP-2壳聚糖微球制备及体外检测.docVIP

rh-BMP-2壳聚糖微球制备及体外检测 　 作者：黄鑫，孟国林，刘建，李丹，袁志，张金康，白建萍 【摘要】 [目的]以壳聚糖为辅料，通过乳化交联法制备新型重组人骨形态发生蛋白-2缓释微球，并对其粒径、载药、体外释药、理化特性及降解特性进行检测，以评估应用生物可降解的壳聚糖微球作为BMP-2缓释载体的可行性。[方法]以京尼平作为交联剂，应用乳化交联法制备具有控制释放功能的负载rhBMP-2壳聚糖微球，应用扫描电镜观察微球的形态和粒径;利用酶联免疫吸附实验(ELISA)动态检测BMP-2壳聚糖微球的载药率、包封率和缓释规律以分析微球的缓释能力。[结果]乳化交联法制备的壳聚糖微球，球形良好，球体表面光滑，具有较高的包封率(gt;85%)。体外药物释放试验表明，rhBMP-2可以从壳聚糖微球中缓慢释放，整个释放过程可达30 d。[结论]应用乳化交联法制备的负载rhBMP-2壳聚糖缓释微球，具有很好的控制释放rhBMP-2的能力。这种新型药物控制释放系统在细胞因子的控制释放及骨组织工程中有潜在的应用价值。 【关键词】 重组人骨形态发生蛋-2; 壳聚糖; 微球; 成骨; 京尼平 　　Abstract: [Objective]To prepare and characterize a novel controlled release system for rhBMP-2 and to evaluate the feasibility of chitosan microsphere as a carrier for controlled release of rhBMP-2. [Methods]The rhBMP-2 loaded chitosan microsphere was prepared using an emulsion cross-linking method with genipin as the cross-linking agent. Scanning electron microscopy was used to evaluate the morphological properties and particle size distribution. An ELISA assay was adopted to determine the actual drug loading and in vitro drug release kinetics.[Results]The rhBMP-2 loaded chitosan microspheres were spherical in shape, and showed a smooth surface and a high encapsulation efficiency (gt;85%). From the in vitro release experiment, the rhBMP-2 was controlled to release from the chitosan microsphere over 30 days.[Conclusion]The rhBMP-2 loaded chitosan microsphere prepared by emulsion cross-linking method shows a good controlled release property. Such a novel type of controlled release system has the potential of being applied for controlled cytokine delivery and the bone tissue engineering. 　　Key words：rhBMP-2; chitosan; microsphere; bone formation; genipin 　　重组人骨形态发生蛋白-2(recombinant human bone morphogenetic protein-2，rhBMP-2)是转化生长因子超家族的一员，具有广泛的生物学活性。研究结果表明，外源性rhBMP-2具有强大的骨诱导活性，因此，rhBMP-2在骨组织工程中具有重要意义[1～3]，然而rhBMP-2的体内半衰期短，全身和局部应用很快被稀释代谢，达不到所期望的生物效果，因此，研究rhBMP-2的缓释方法具有重要的理论和实际应用价值[4、5]。本实验采用乳化交联法制备rhBMP-2壳聚糖载药微球，制备出粒径适宜的缓释微球，并对所制备微球的理化特性进行研究。 　　1 材料和方法 　　1.1 rhBMP-2壳聚糖微球的制备 　　采用乳化交联法制备