Triple Responsive Block Copolymers Combining pH-Responsive, Thermoresponsive, and Glucose-Responsive Behaviors

Polymers with multiple tunable responses were achieved by incorporating boronic acid functionality along the backbone of a thermoresponsive polymer. The inherent Lewis acidity and diol-sensitivity of boronic acid moieties allowed these polymers to respond to changes in pH and glucose concentration. Through reversible addition-fragmentation chain transfer copolymerization of boronic acid-containing monomers with N-isopropylacrylamide, well-defined block copolymers were synthesized containing a hydrophilic N, N-dimethylacrylamide block and a second, responsive block with temperature-dependent water solubility, making the resulting polymers capable of self-assembly into nanostructures upon heating. By incorporating boronic acids within the thermoresponsive block, the cloud point of the polymer depended on the solution conditions, including pH and diol concentration, allowing tunable cloud point ranges. (C) 2017 Wiley Periodicals, Inc.