The glucose-responsive behavior of a block copolymer featuring boronic acid and glycine

Glucose responsive block copolymer featuring boronic acid as a glucose responsive moiety and glycine are reported. The first block is polymerized through reversible addition-fragmentation chain transfer (RAFT) polymerization and the resulting poly(N-acryloylmorpholine)(113) (PAcM) is employed as a macro-chain transfer agent for chain extension with pentafluorophenyl acrylate (PFPA) yielding a well-defined PAcM113-block-poly(pentafluorophenyl acrylate)(84) (PPFPA). The PPFPA block is then reacted with functional (3-aminomethyl) phenyl boronic acid and glycine via post-polymerization modification and the structure of the block copolymer is confirmed by proton nuclear magnetic resonance (NMR), F-19 NMR, Fourier transform infrared, and gel permeation chromatography. By copolymerizing glycine into the polymer backbone, the relative pK(a) of the block copolymer is significantly lowered. The block copolymer can self-assemble into core-shell micelles in aqueous solution and disassemble in response to glucose at the physiological pH. Furthermore, the encapsulation and release of Nile red (NR) as a hydrophobic model drug is studied under the physiological pH. The influence of the glucose concentration on the NR release from the polymeric micelles is demonstrated. These results suggested that the glucose-responsive poly[(AcM)(113)-b-(3-(aminomethyl)phenylboronic acid hydrochloride(-co-Gly)(84)] block copolymer has potential applications as a glucose-responsive polymer for insulin delivery. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 422-431