水相-水相乳化法制备载BSA的葡聚糖微粒

Aqueous Phase-Aqueous Phase Emulsion Method to Prepare BSA-loaded Dextran Microparticles

目的采用水相-水相乳化法,制备粒径小且分布集中的载蛋白的葡聚糖(Dx)微粒。方法 Dx/聚乙二醇(PEG)双水相系统将蛋白富集于Dx相,两相按比例混匀得PEG包Dx型类乳液。添加海藻酸钠于PEG相作稳定剂,经冻干、除PEG后,得载牛血清白蛋白(BSA)的Dx微粒。采用显微镜及软件分析微粒外观和粒径数据,BCA法测定微粒的包封率和载药量,差示扫描量热器测定微粒及其成分的熔融吸热峰。结果优化的载药微粒圆整均一、平均粒径约5μm,载药量、包封率分别在16%、88%以上。结论水相-水相乳化法可制备出粒径小且分布集中、载药性能良好的蛋白-Dx微粒。该法可进一步应用于干粉吸入剂或缓释微球等剂型的研究。

Objective To produce protein-loaded dextran （Dx） microparticles by aqueous phase-aqueous phase emulsion method, which were fine powders with narrow particle size distribution. Methods Protein can be enriched in Dx phase of the aqueous two-phase system ＂Dx/polyethylene （PEG）＂ which was mixed in certain ratio to form a kind of Dx in PEG ＂emulsion＂. To stabilize the ＂emulsion＂, sodium alginate was added into PEG phase. Then after freeze-dried and PEG removal, bovine serum albumin （BSA） loaded Dx microparticles were prepared. The sizes of microparticles were observed under microscope and analyzed by software, while the loading percentage and entrapment efficiency were determined by BCA method. Differential Scanning Calorimeter was utilized to test whether BSA was entrapped into the microparticles. Results The diameter of the optimized spherical BSA-Dx microparticles was about 5 p,m in average, with the drug-load percentage and encapsulation efficiency over 16% and 88%, respectively. Conclusion Aqueous phaseaqueous phase emulsion method is an effective way to entrap proteins into Dx fine particles, which is uniform in size, with high drug-load capacity. These protein-containing microparticles may further be encapsulated into different dosage forms like microspheres, or be directly applied as a dosage form like inhalation powders.