Abstract: Relatively uniform-sized lysozyme-loaded microspheres made of monomethoxy poly(ethylene glycol)-b-poly-DL-lactide (PELA) were prepared by combining premix membrane emulsification and double emulsion-solvent removal method. The effects of polymer composition and organic solvent type on the protein encapsulation efficiency and bioactivity were studied. The results showed that the PELA microspheres could be efficiently prepared by this method, and the coefficient of variation (CV) value of microspheres was less than 20% under the volumetric ratio of oil phase to outer aqueous phase 1:6. This method was universal for different polymer compositions and types of organic solvent. PELA microspheres loading lysozyme were prepared through a W/O/W double emulsion-solvent diffusion method using ethyl acetate as organic solvent. The microspheres had a high protein entrapment rate over 95.7% and full preservation of bioactivity of entrapped lysozyme.

Key words: premix membrane emulsification, PELA microspheres, encapsulation rate, bioactivity, uniform size, amphiphilic membrane polymer

摘要： 采用快速膜乳化技术与复乳-溶剂去除法制备了尺寸均一的单甲氧基聚乙二醇-聚-DL-乳酸(PELA)载溶菌酶微球，比较了膜材种类和有机溶剂类型对微球中药物包埋率和活性保持的影响. 研究结果表明，该方法能快速制备粒径均一的载药微球，在油相与外水相体积比为1:6的条件下，微球粒径分布系数小于20%，而且该方法对膜材和有机溶剂有很好的普适性. 以PELA为膜材、乙酸乙酯为有机溶剂，采用溶剂扩散法制备的载药微球包埋率高达95.7%，并且能保持高的活性.

关键词: 膜乳化, PELA微球, 包埋率, 生物活性, 均一性, 两亲性膜材