"Breathing" CO -, O -, and Light-Responsive Vesicles from a Triblock Copolymer for Rate-Tunable Controlled Release.

A well-defined amphiphilic triblock copolymer, poly[(ethylene glycol)methyl ether]-block-poly(N,N-dimethylamino ethyl methacrylate-co-2,2,2-trifluoroethyl methacrylate)-block-poly(4-(4-methoxy-phenylazo)phenoxy methacrylate) (PEG-b-P(DMAEMA-co-TFEMA)-b-PMEPPMA), is successfully synthesized by stepwise atom transfer radical polymerization. Owing to its amphiphilic nature, PEG-b-P(DMAEMA-co-TFEMA)-b-PMEPPMA can self-assemble into vesicles in aqueous solution and exhibits a reversible triple-responsive behavior toward CO , O , and light stimuli. More importantly, such vesicles can exhibit a controlled "breathing" behavior via external stimuli due to their suitable chemical structure and stimuli responsiveness. Consequently, these vesicles can be employed as nanocarriers for rate-tunable controlled release via adjustment of their membrane permeability by a single stimulus or various stimuli combinations.