Light-Triggered Adhesion of Water-Soluble Polymers with a Caged Catechol Group

An acrylamide-type copolymer containing hydroxyl, amino, and ortho-nitrobenzyl protected catechol groups was synthesized as a functional mussel adhesive protein (MAP) mimetic. The resulting copolymer was stable even in the oxidative condition. Light irradiation to aqueous solution of the copolymer induced deprotection of a caged compound to give a native catechol group and triggered an oxidative cross-linking reaction to afford the adhesive gel. Two glass plates were adhered through light-activated gelation of the polymer solution in a humid air atmosphere. A novel type of light-activated adhesive with excellent stability and light controllable activation properties was successfully fabricated by modification of the MAP mimetic copolymer.