Li Xialin, Min Shaoxiong, Zhao Xiaoyan, Lu Zhifang, Jin Anmin
Department of Orthopaedics, Zhujiang Hospital affiliated with Southern Medical University Guangzhou, Guangzhou 510282, People's Republic of China.
Biomed Mater. 2014 Dec 23;10(1):015002. doi: 10.1088/1748-6041/10/1/015002.
A microcapsule prepared from triblock copolymer poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA, PELA) was investigated as a controlled release carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2). The rhBMP-2/PELA microspheres were prepared using the water-in-oil-in-water (W/O/W) solvent evaporation method. This work was conducted to optimize the entrapping conditions of the rhBMP-2 loaded PELA copolymer. The effects on encapsulation efficiency (EE) of different molecular weights (MW) of PEG in the copolymer, the amount of PELA, the amount of rhBMP-2, the span-20 concentration, the polyvinyl alcohol (PVA) concentration and stirring time were tested. On the basis of single-factor experiments, the optimum parameters were achieved using response surface methodology (RSM). The results showed that the highest EE of BMP-2 was achieved with a span-20 concentration of 0.5%, PEG MW 4000 Da, a stirring time of 30 min at 800 rpm min(-1), 282.3 mg of PELA, 1 μg of rhBMP-2 and PVA concentration 0.79%. Under these optimal conditions, it was predicted that the highest EE to be achieved would be 76.5%; the actual EE achieved was 75%.
研究了由三嵌段共聚物聚乳酸-聚乙二醇-聚乳酸（PLA-PEG-PLA，PELA）制备的微胶囊作为重组人骨形态发生蛋白-2（rhBMP-2）的控释载体。采用水包油包水（W/O/W）溶剂蒸发法制备了rhBMP-2/PELA微球。开展这项工作是为了优化负载rhBMP-2的PELA共聚物的包封条件。测试了共聚物中不同分子量（MW）的PEG、PELA用量、rhBMP-2用量、司盘-20浓度、聚乙烯醇（PVA）浓度和搅拌时间对包封率（EE）的影响。在单因素实验的基础上，采用响应面法（RSM）获得了最佳参数。结果表明，当司盘-20浓度为0.5%、PEG分子量为4000 Da、在800 rpm min⁻¹下搅拌30 min、PELA为282.3 mg、rhBMP-2为1 μg且PVA浓度为0.79%时，BMP-2的包封率最高。在这些最佳条件下，预计可实现的最高包封率为76.5%；实际实现的包封率为75%。
