纤维蛋白胶复合重组人骨形态发生蛋白2微球的制备及评价

背景:采用生理盐水溶解重组人骨形态发生蛋白2/聚乳酸-聚乙醇酸共聚物微球时,活性成分易于吸收、流失,不能在局部维持较高浓度;而采用静脉血或骨髓血溶解时凝固时间难以掌握,往往在体外已凝血,失去可注射性,操作不便,因此还需一种能控制凝固时间的缓释载体.目的:制备携载重组人骨形态发生蛋白2的聚乳酸与聚乙醇酸缓释微球并将其与纤维蛋白胶复合,构建具有自固化能力的可注射性骨形态发生蛋白缓释体系.设计、时间及地点:对比观察实验,于2005-01/2008-04在解放军总医院骨科研究所完成.材料:聚乳酸-聚乙醇酸共聚物(聚乳酸/聚乙醇酸75/25,M_W=3 000,黏度0.025 L/g)由山东省医疗器械研究所提供,重组人骨形态发生蛋白2由解放军军事医学科学院提供,纤维蛋白胶由杭州普济公司提供.方法:复乳-溶剂挥发法制备重组人骨形态发生蛋白2/聚乳酸-聚乙醇酸共聚物载药微球,然后将微球与纤维蛋白胶复合制备出重组人骨形态发生蛋白2/聚乳酸-聚乙醇酸共聚物/纤维蛋白胶复合材料.主要观察指标:复合材料凝固时间、体外释放性质、能谱分析及体外降解液pH值.结果:①与纤维蛋白胶相比,复合材料的固化时间少量增加.②复合材料的释放存在突释,2d骨形态发生蛋白释放量达到16.76%,42 d释放量达到76.75%.③能谱分析显示微球混入纤维蛋白胶后优化了释放过程,延长了其释放时间.④复合材料的pH值变化介于微球与纤维蛋白胶之间.结论:重组人骨形态发生蛋白2/聚乳酸-聚乙醇酸共聚物/纤维蛋白胶复合材料具有良好的缓释效果并具有可注射性,既可以降低局部的酸环境,又可以在局部维持较高浓度,是具有良好应用前景的骨修复材料.

Preparation and evaluation of recombinant human bone morphogenetic protein-2 loaded microsphere combined with fibrin glue

BACKGROUND: The active component in recombinant human bone morphogenetic protein-2/poly(lactide-co-glycolide)(rhBMP-2/PLGA) microsphere prone to be absorbed or lost during solution with physiological saline, and the setting time isuncontrollable using blood solution, so it is necessary to explore an sustained-release carrier that can control the setting time.OBJECTIVE: To construct an injectable BMP release system by combing rhBMP-2/PLGA microsphere with fibrin glue.DESIGN, TIME AND SETTING: An experimental comparative study was performed at the Department of Othopaedics, General Hospital of Chinese PLA from January 2005 to April 2008.MATERIALS: PLGA (polylactic acid/polyglycolic acid 75/25, M_r=3 000, with 0.025 L/g viscosity) was supplied by Shandong Institute of Medical Instruments; rhBMP-2 was offered by The Academy of Military Medical Sciences; and fibrin glue was supplied by Hangzhou Puji Medicine Technology Development Co., Ltd.METHODS:The rhBMP-2/PLGA microsphere was prepared using W/O/W solvent evaporation methods. rhBMP-2 loaded PLGA microsphere were incorporated in fibrin glue to establish injectable BMP release system.MAIN OUTCOME MEASURES: The setting time,release behaviors, electron spectroscopy for chemical analysis (ESCA) as well as pH values of composites were measured.RESULTS:①Compared with fibrin glue, the setting time of composites were slightly increased.②Initial burst release of the composites occurred, the drug release exceeded 16.76% within 2 days, and 76.75% of the drug was release within 42 days. ③ESCA showed that composites prolonged release times.④The PH value of composites was between microsphere and fibrin glue.CONCLUSION: RhBMP-2/PLGA microsphere/fibrin glue composite has satisfactory slow-release effect and syringeability, which not only degrade partial acid environment but also maintain the biological effect of higher density. Therefore, it forms a promising synthetic bone graft.