Triple stimuli-responsive amphiphilic glycopolymer

Triple stimuli (temperature/pH/photo)-responsive amphiphilic glycopolymer, poly(2-(dimethylamino)ethyl methacrylate-co-6-O-methacryloyl-1,2,3,4-di-O-isopropylidene-D-galactopyranose)-b-poly(4-(4-methoxyphenylazo)phenoxy methacrylate) [P(DMAEMA-co-MAIpGP)-b-PMAZO] was synthesized by atom transfer radical polymerization, followed by the hydrolysis of MAIpGP groups, resulting in the target product poly(2-(dimethylamino)ethyl methacrylate-co-6-O-methacryloyl-D-galactopyranose)-b-poly(4-(4-methoxyphenylazo)phenoxy methacrylate) [P(DMAEMA-co-MAGP)-b-PMAZO]. The composition, moleculer weight, and moleculer weight distribution of the resultant polymers were characterized by 1H NMR and gel permeation chromatography. The micelles formed in aqueous solutions were simulated by various chemical and physical stimuli and characterized by dynamic light scattering, transmission electron microscopy, and UV-vis spectroscopy. It was found that the glycopolymer is responsive to three different types of stimulus (light, temperature, and pH). The poly(2-(dimethylamino) ethyl methacrylate) segments give thermo- and pH-responsiveness. The presence of the azobenzene moiety endows the block copolymer to exhibit light-responsiveness due to its reversible trans-cis isomerization conversion. The triple stimuli-responsive glycopolymer micelles can simulate biomacromolecues in vivo/in vitro environment and can be expected to open up new applications in various fields. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2131–2138