Drug release of pH-sensitive poly(L-aspartate)-b-poly(ethylene glycol) micelles with POSS cores
writer：Yuji Pu, Longgui Zhang, Hui Zheng, Bin He*, Zhongwei Gu*
keywords：pH-sensitive poly(L-aspartate)-b-poly(ethylene glycol) micelles
source：期刊
specific source：Polym. Chem. 2014, 5: 463-470
Issue time：2014年
Amphiphilic poly(L-aspartate)-b-poly(ethy1ene glycol) block copolymers were synthesized and immobilized on polyhedral oligomeric silsesquioxanes (POSS) to receive star shape copolymers. 1-(3-Aminopropyl) imidazole was conjugated on the pendant groups of poly(L-aspartate) segments to fabricate pH-sensitive micelles. Anticancer drug doxorubicin (DOX) was trapped in the micelles to investigate the effects of side groups on the drug release behaviors. The mean diameters of DOX loaded micelles were around 50-60 nm, which were much smaller than those of blank micelles (100-200 nm). Both the drug loading content and encapsulation efficiency of the micelles decreased with the sequence of side group substitution of carboxyl, benzy1 and imidazole. The release of DOX loaded micelles with imidazole groups was pH-dependent, more than 90% of the loaded DOX could be released within 48 hours in weak acidic medium (pH=5.0). The flow cytometry and confocal laser scanning microscopy results revealed that the pH-sensitive micelles exhibited better anticancer activity.