18. pH-Sensitive Polymeric Micelles Based on Amphiphilic Polypeptide as Smart Drug Carriers
writer：Yi Li, Guang Hui Gao, Doo Sung Lee
keywords：diblock copolymers, drug delivery systems, micelles
source：期刊
specific source：JOURNAL OF POLYMER SCIENCE
Issue time：2013年
A series of amphiphilic diblock copolymers having poly(ethylene glycol) (PEG) as one block and a polypeptide as the other block were synthesized by ring-opening polymerization using PEG-amine as a macroinitiator. These polymers were characterized by 1H-NMR and gel permeation chromatography. The influence of the substitution ratio of tertiary amine-containing groups on the pH sensitivity of the polymers was investigated in detail. Core/shell-structured micelles were fabricated from these polymers using an organic solvent-free method. pH- and concentration-dependent micellization behaviors were investigated by dynamic light scattering and fluorescence microscopy. Micelles loaded with doxorubicin, selected as a model drug, showed restricted drug release at physiological pH but accelerated drug release at tumor extracellular pH. Collectively, our findings suggest that these pH-sensitive micelles might have
great potential for cancer therapy applications.