Ruan Gang, Feng Si-Shen, Li Qiu-Tian
Department of Chemical and Environmental Engineering, Faculty of Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore.
J Control Release. 2002 Dec 5;84(3):151-60. doi: 10.1016/s0168-3659(02)00292-4.
Human serum albumin (HSA) was encapsulated as a model protein in microspheres of biodegradable and biocompatible polymers by the water-in-oil-in-water (w/o/w) emulsion solvent extraction/evaporation (double emulsion) technique for purpose of controlled release. To improve the properties and control the rate of drug release of the delivery vehicle, materials with different hydrophobicity from that of their conventional counterparts, such as poly(lactide-co-ethylene glycol) (PELA) in place of poly(lactide-co-glycolide) (PLGA) as the polymer matrix, ethyl acetate/acetone in place of dichloride methane (DCM) as the (co)solvent and d-alpha tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) as the additive, were used to prepare the microspheres. It has been found that PELA microspheres, compared with PLGA ones, were slightly smaller in size if prepared at identical emulsification strength. They had more porous surface and internal structure, higher encapsulation efficiency (EE) and more rapid in vitro release rate. Furthermore, the physical properties of the microspheres were also affected by the presence of solvents and additives and their properties. Our results suggest that these materials could have interesting potential applications in preparation of polymeric microspheres for controlled protein release.
为实现控释目的，采用水包油包水（w/o/w）乳液溶剂萃取/蒸发（双乳液）技术，将人血清白蛋白（HSA）作为模型蛋白包裹于可生物降解且生物相容的聚合物微球中。为改善给药载体的性能并控制药物释放速率，使用了与传统材料疏水性不同的材料，如用聚（丙交酯-共-乙二醇）（PELA）代替聚（丙交酯-共-乙交酯）（PLGA）作为聚合物基质，用乙酸乙酯/丙酮代替二氯甲烷（DCM）作为（共）溶剂，并用d-α生育酚聚乙二醇1000琥珀酸酯（维生素E TPGS）作为添加剂来制备微球。已发现，在相同乳化强度下制备时，PELA微球与PLGA微球相比尺寸略小。它们具有更多孔的表面和内部结构、更高的包封率（EE）以及更快的体外释放速率。此外，微球的物理性质也受溶剂和添加剂的存在及其性质的影响。我们的结果表明，这些材料在制备用于控释蛋白质的聚合物微球方面可能具有有趣的潜在应用。
