Glucose-Sensitivity of Boronic Acid Block Copolymers at Physiological pH

Well-defined boronic acid block copolymers were demonstrated to exhibit glucose-responsive disassembly at physiological pH. A boronic acid-containing acrylamide monomer with an electron-withdrawing substituent on the pendant phenylboronic acid moiety was polymerized by reversible addition–fragmentation chain transfer (RAFT) polymerization to yield a polymer with a boronic acid pKa = 8.2. Below this value, a block copolymer of this monomer with poly(N,N-dimethylacrylamide) self-assembled into aggregates. Addition of base to yield a pH > pKa or addition of glucose at pH = 7.4 resulted in aggregate dissociation that may prove promising for controlled delivery applications under physiological relevant conditions.