In the present study, glucose-responsive polymeric complex micelles based on the complexation of phenylboronic-acid-based (PBA-based) block copolymer and diol-functionalized polymers are reported. The phenylboronic-acid- and diol-based block copolymers were successfully synthesized in only two reaction steps using reversible addition–fragmentation chain-transfer (RAFT) polymerization and postpolymerization modification of the obtained poly­[(N-acryloylmorpholine-block-(N-acryloylmorpholine-co-pentafluorophenyl acrylate)], poly­[(AMP-b-(AMP-co-PFPA)], reactive block copolymer. The self-assembly of the complex micelles was investigated under neutral conditions using dynamic light scattering (DLS) and transmission electron microscopy (TEM). The interaction of the PBA block copolymer and diol-containing polymer via boronate ester bond was investigated by 1H NMR and UV–vis spectroscopy. The complex micelles enhanced the glucose responsiveness under physiological conditions compared to simple PBA micelles. Furthermore, the successful glucose-triggered release of FITC–insulin from the polymeric micelles was investigated.

Physically crosslinked hydrogels based on N‐vinylcaprolactam/acrylic acid and N‐vinylcaprolactam/methacrylic acid were prepared via free radical polymerization. These temperature responsive hydrogels were characterized in terms of glass transition, phase separation temperature, potentiometric titration and swelling properties. Results showed that phase transition temperature was dependent on the pH value of the solution; increasing pH led to higher lower critical solution temperature (LCST) values which was related to the dissociative behaviors of the carboxylic group of MAc in the buffered solutions. Additionally, with the incorporation of N,N‐dimethylacrylamide into the system, cloud point measurements and MDSC showed an increased in the LCST. This increase was based on hydrophilicity, the hydrophilic–hydrophobic balance was disturbed, and consequently, the LCST behavior was shifted. The pKa of the copolymers ranged between 5.6 and 6.5, while for the terpolymers pKa ranged between 5.3 and 6. At high pH (>10), the COOH group is deprotonated and negatively charged (COO−), while at low pH (1–3) the carboxylic group remains protonated which results in hydrogen bonding between the hydroxyl groups (from NaOH) and the excess of HCl. These results correlate with swelling studies where above the pKa value the hydrogels dissolved rapidly compared to below pKa they did not dissolve at all. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1555–1564

A novel pH- and sugar-responsive diblock copolymer containing phenylboronic acid was synthesized by RAFT and a post-polymerization modification strategy.

This manuscript is dedicated to Professor Mitsuo Sawamoto's outstanding achievements in polymer chemistry and recognizes his recent retirement from 40 years of exceptional service to Kyoto University.ABSTRACT: Glucose responsive block copolymer featuring boronic acid as a glucose responsive moiety and glycine are reported. The first block is polymerized through reversible additionfragmentation 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 PAcM 113 -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), 19 F 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.Additional supporting information may be found in the online version of this article.

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