Caponetti G, Hrkach J S, Kriwet B, Poh M, Lotan N, Colombo P, Langer R
Massachusetts Institute of Technology, Department of Chemical Engineering, E25-342, Cambridge, Massachusetts 02139, USA.
J Pharm Sci. 1999 Jan;88(1):136-41. doi: 10.1021/js970457f.
The preparation and characterization of microparticles produced from a new class of functionalized, biodegradable, comblike graft copolymers is presented. The copolymers are polyester-polyamino acid hybrids, composed of a poly(L-lactic acid-co-L-lysine) (PLAL) backbone, and poly(L-lysine), poly(D,L-alanine) or poly(L-aspartic acid) side chains extending from the lysine residues of PLAL. The microparticles have been characterized with regard to their surface properties, morphology, and size. Thus, electron spectroscopy for chemical analysis data and results of Zeta potential measurements suggest that the polyamino acid side chains tend to concentrate at the surface of the particles. Also, analyses by environmental scanning electron microscopy and confocal scanning laser microscopy indicate that particles carrying poly(lysine) chains have an unusual porous structure, most probably due to the combined effects of the amphiphilic, polyelectrolyte, and chemical nature of the composing copolymer, as well as of the particular preparation technique employed. The capabilities of the microparticles to serve as carriers in controlled drug release and delivery devices were demonstrated by encapsulation and release of rhodamine B, a low molecular weight drug model.
本文介绍了一类新型功能化、可生物降解梳状接枝共聚物制备的微粒及其表征。这些共聚物是聚酯 - 聚氨基酸杂化物，由聚（L - 乳酸 - 共 - L - 赖氨酸）（PLAL）主链以及从PLAL的赖氨酸残基延伸出的聚（L - 赖氨酸）、聚（D，L - 丙氨酸）或聚（L - 天冬氨酸）侧链组成。已对微粒的表面性质、形态和尺寸进行了表征。因此，化学分析数据的电子能谱和Zeta电位测量结果表明，聚氨基酸侧链倾向于集中在颗粒表面。此外，环境扫描电子显微镜和共聚焦扫描激光显微镜分析表明，带有聚（赖氨酸）链的颗粒具有异常的多孔结构，这很可能是由于组成共聚物的两亲性、聚电解质和化学性质以及所采用的特定制备技术的综合作用。通过低分子量药物模型罗丹明B的包封和释放，证明了微粒作为控释和给药装置载体的能力。
