基于PEG-PCL-PLLA杂臂星形高分子胶束的合成与性能

聚己内酯(PCL)和聚L-乳酸(PLLA)是胶束中常用的生物可降解高分子材料,将PCL和PLLA共聚或共混能改善PCL降解缓慢的缺陷,但PCL和PLLA同时作为杂臂星形高分子胶束的疏水部分却鲜少研究。文中合成了基于PEGPCL-PLLA的ABC杂臂星形高分子胶束与对应的线型三嵌段高分子胶束,研究了聚合物的不同结构对高分子胶束的结晶和粒径的影响。二者的化学结构、相对分子质量及其分布、结晶行为和粒径由核磁共振、差示扫描量热和动态光散射等测试来表征,其结果表明杂臂星形高分子胶束具有比线型嵌段高分子胶束有更强的结晶能力和更小的粒径。

Synthesis and Properties of Miktoarm Star Polymeric Micelle Based on PEG-PCL-PLLA

Polycaprolactone (PCL) and poly L-lactic acid (PLLA),the common biodegradable polymers for drug carriers,were investigated extensively.Also,modification of PCL with PLLA could improve the degradation rate of PCL.However,nearly no researches were focused on the combination of PCL and PLLA as hydrophobic segments in biodegradable miktoarm star polymeric micelles.In this paper,biodegradable ABC miktoarm star polymeric micelle based on PEG-PCL-PLLA and its linear counterpart were synthesized by click chemistry and ring-opening polymerization (ROP) to investigate the effect of different architectures on the crystallization behavior and size of polymeric micelles.Their chemical structure,molecular weight,molecular weight distribution,crystallization behavior and size were characterized by 1H-NMR,DSC,DLS,etc.The results reveal that that miktoarm star polymeric micelles have stronger crystallization capacity and smaller size,comparing with linear triblock polymeric micelles.