Photoresponsive hybrid hydrogel with a dual network of agarose and a self-assembling peptide.

Abstract

Responsive hybrid hydrogels composed of a self-assembling low molecular weight gelator and a polymeric network are of particular interest for the development of smart nanomaterials. Key advantages of such hybrid hydrogels are their ease in preparation as well as their unique mechanical properties. Herein we describe a photoresponsive peptide AAP-FGDS, which exhibits excellent photochemical properties and highly reversible changes in the rheological properties. Addition of AAP-FGDS to a covalent, non-responsive agarose network gives rise to a robust hybrid hydrogel with phototunable mechanical properties and shape memory. Upon irradiation with UV light the self-assembled three dimensional structure disaggregates to yield a softer yet self-supporting hydrogel. Irradiation with visible light followed by the reassembly of the peptide allows the fixation of a different shape programmed by mechanical deformation. Upon repeated deactivation of the peptide network the original shape is recovered.