Complex micelles with a responsive shell for controlling of enzymatic degradation |
| |
Authors: | Yanling Xu Rujiang Ma Zhenkun Zhang Huan He Yaozong Wang Aoting Qu Yingli An XX Zhu Linqi Shi |
| |
Affiliation: | 1. Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China;2. Département de Chimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C 3J7, Canada |
| |
Abstract: | Complex polymeric micelles with a PLA core and a mixed PEG/PNIPAM shell were prepared by self-assembly of two block copolymers: poly(ethylene glycol)-b-poly(lactic acid) (PEG-b-PLA) and poly(N-isopropylacrylamide)-b-poly(lactic acid) (PNIPAM-b-PLA). Using 1H NMR spectroscopy and dynamic light scattering, the micellization and the enzymatic degradation status were characterized. At 25 °C, the PNIPAM block is hydrophilic and the PLA core is prone to the enzymatic degradation, resulting in the disassembly of the micelles. While increasing the temperature to 45 °C, the PNIPAM collapsed onto the PLA core, protecting the PLA core from the attack by the enzyme, and the micelles exhibit a resistance to the enzymatic degradation. Furthermore, the enzymatic degradation rate of the micelles can also be tuned by changing the ratio of PEG to PNIPAM. With increasing content of PNIPAM, the conformation of the collapsed PNIPAM changes from patchy domains to a continuous and dense layer, and the enzyme accessibility to the PLA core is changed. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|