Methionine-Based pH and Oxidation Dual-Responsive Block Copolymer: Synthesis and Fabrication of Protein Nanogels.

Methionine-Based pH and Oxidation Dual-Responsive Block Copolymer: Synthesis and Fabrication of Protein Nanogels. Biomacromolecules. 2020 Sep 11;: Authors: Dong S, Jiang Y, Qin G, Liu L, Zhao H Abstract In this paper, we synthesized a block copolymer containing pendent thioether functionalities by RAFT polymerization of tert-butyloxycarbonyl (Boc)-L-methionine-(2-methacryloylethyl)ester (Boc-METMA) monomer using a poly(ethylene glycol) (PEG)-based chain transfer agent. The deprotection of Boc groups resulted in an oxidation and pH dual-responsive cationic block copolymer PEG-b-P(METMA). The block copolymer PEG-b-P(METMA) possessing protonable amine groups was water soluble at pH<6.0, and self-assembled to form spherical micelles at pH > 6.0. In the presence of H2O2, the micelles first became highly swollen with time and completely disassembled at last, demonstrating H2O2-responsive feature due to the oxidation of hydrophobic thioether to hydrophilic sulfoxide. The anticancer drug curcumin (Cur) was entrapped into the polymeric micelles and the Cur-loaded micelles displayed a H2O2-triggered release profile as well as a pH-dependent release behavior, making PEG-b-P(METMA) micelles promising nanocarriers for ROS-responsive drug delivery. Taking advantage of the protonated amine groups, the cationic polyelectrolyte PEG-b-P(METMA) formed polyion complex (PIC) micelles with glucose oxidase (GOx) through electrostatic interaction at p...
Source: Biomacromolecules - Category: Biochemistry Authors: Tags: Biomacromolecules Source Type: research