pH-Responsive H-Type PMAA2-b-HTPBN-b-PMAA2 Four-Arm Star Block Copolymer Micelles for PTX Drug Release

pH-Responsive H-type poly(methylacrylic acid- block -four hydroxyl terminated poly(butadiene-acrylobitrile)- block -poly(methylacrylic acid (PMAA 2 - b -HTPBN- b -PMAA 2 ) block copolymers were synthesized via atom transfer radical polymerization and the follow-up hydrolysis, and characterized by 1 H NMR, FT-IR and SEC . The block copolymers could self-assemble into nanoscale spherical core-shell micelle aggregates in aqueous solution, and the physicochemical properties depended on the system composition and pH media, with pH phase transition at 5.7–6.1. The copolymer micelle aggregates exhibited pH-triggered drug release and cytotoxicity, and could potentially be used as drug targeting release carriers.