Photocleavable glycopolymer aggregates

Abstract

We present here a water soluble diblock glycopolymer, poly(spiropyran methacrylate)-block-poly(3-O-4-vinylbenzoyl-D-glucopyranose) (PSP-b-PBG), synthesized by the conventional atom transfer radical polymerization (ATRP) technique. Irradiation with UV light results in switching of the hydrophobic colorless spiropyran (SP) form to zwitterionic purple coloured merocyanine (MC) increasing the overall polarity of the glycopolymer, resulting in its enhanced affinity towards water. The MC form reverts back to the SP form in the dark or under visible light irradiation, restoring the amphiphilic nature of the polymer. Vesicular aggregates formed by this diblock copolymer in water could be dissociated and reconstructed by alternate UV and visible light irradiation. The ability of these polymersomes to efficiently encapsulate, release and re-encapsulate a hydrophobic dye was also explored.