通过开环聚合(ROP)、DCC 偶合反应及原子转移自由基聚合(ATRP)合成3种不同臂数(线性、三臂和六臂)的聚己内酯-b-聚乙二醇-b-聚甲基丙烯酸(2-羟乙酯)(PCL-PEG-PHEMA)三嵌段共聚物。通过核磁氢谱(1 H NMR)红外谱图证明合成了设计产物。以溶剂挥发法制备胶束并进行载药实验。用激光粒度仪测定胶束粒径、粒径分布及zeta电位,用荧光光谱仪以芘荧光探针法测定临界胶束浓度,用紫外-可见分光光度计表征胶束载药量、包封率。结果表明,3种三嵌段共聚物均能形成稳定的载药胶束,其中具有星形结构的六臂的三嵌段共聚物具有最低的胶束粒径和临界胶束浓度、最高的载药量和包封率。因此,星形六臂的PCL-PEG-PHEMA可作为新的药物载体材料。
Three triblock copolymers of poly (ε-caprolactone)-b-poly (ethylene glycol)-b-poly (2-hydroxyethyl methacrylate)(PCL-PEG-PHEMA)with different number of arms(linear,3s,6s)were synthesized by a combi-nation of ring-opening polymerization,coupling reaction with DCC and atom transfer radical polymerization (ATRP).The 1 H NMR spectra and FT-IR spectra showed that the products were synthesized as expected.The micelles and drug-loaded micelles of the three copolymers were prepared by solvent evaporation method.The micellar particle size,particle size distribution and zeta potential were determined with a zetasizer equipment. The critical micelle concentration (CMC)was determined with a fluorescence spectroscopy using pyrene as a hy-drophobic probe.Drug content and the encapsulation efficiency of drug-loaded micelles were determined with a UV-Vis spectrophotometer.The result indicated that all the three triblock copolymers could form stable drug-loaded micelles.The micelles formed by star-shape six arms copolymer demonstrated the smallest particle size , the lowest CMC value,the most excellent drug content and encapsulation efficiency.So,star-shape six arm PCL-PEG-PHEMA may be a good candidate as a material for drug deliver systems.