聚乳酸-羟基乙酸共聚物对牛血清蛋白微囊化和微球表征

Microencapsulation of BSA via PLGA and Microsphere Characterization

目的:利用不同配比聚乳酸-羟基乙酸共聚物(PLGA),采用双乳化法,将异硫氰酸荧光素标记的牛血清白蛋白(BSA-FITC)包封制成微球;考察PLGA共聚物比例和相对分子质量对微球平均粒径、包封效率和释放方式的影响。方法:将异硫氰酸荧光素标记的牛血清蛋白溶解在乙酸乙酯中,超声波频率28 kHz,功率40 W,超声波作用时间5 min,以形成水/油乳液;将初级乳液快速转移到含聚乙烯醇的水性介质,通过两次乳化处理后,得到微球;计算产品收率、封装效率、微球粒度分布和释放量。结果:异硫氰酸荧光素标记的牛血清白蛋白包埋在聚乳酸-羟基乙酸共聚物微球中,当共聚物聚乳酸与羟基乙酸质量比为75∶25(MW 40~75 kDa)时,具有最高的产品收率和封装效率,分别为51.04%和100%;通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析异硫氰酸荧光素标记的牛血清白蛋白释放结果,释放量低于25%。结论:PLGA可作为生物药品的包封材料。

Objective:Using double emulsification method,BSA-FITC microspheres were prepared by PLGA of different proportions.The effects of PLGA copolymer ratio and molecular weight on the average particle size,encapsulation efficiency and release mode of PLGA microspheres were investigated.Methods:Fluorescein isothiocyanate-labeled bovine serum protein was dissolved in ethyl acetate solution at a frequency of 28 kHz,power of 40 W and Sonication time of 5 min to form an aqueous oil emulsion.The primary emulsion was transferred to the aqueous medium containing polyvinyl alcohol quickly,and then the microspheres were obtained after postprocessing with two times of emulsification.The product yield,encapsulation efficiency,particle size distribution and release amount were calculated.Results:BSA labeled with fluorescein isothiocyanate was embedded in PLGA microspheres.When the ratio of PLGA to PLGA was 75:25(MW 40~75 kDa),the highest product yield and encapsulation efficiency were 51.04%and 100%,respectively;The release of fluorescein isothiocyanate labeled bovine serum albumin was analyzed by twelve alkyl sulphate polyacrylamide gel electrophoresis,and the release amount was less than 25%.Conclusion:PLGA can be used as an encapsulation material for biopharmaceuticals.