Fabrication of a Shape Memory Hydrogel Based on Imidazole-zinc Ion Coordination for Potential Cell-encapsulating Tubular Scaffold Application

A dipole-dipole reinforced copolymer hydrogel was synthesized by one-stepphotopolymerization of vinylimidazole (VI), acrylonitrile (AN) comonomer in thepresence of polyethylene glycol-based crosslinker. The mechanical properties ofPVI-AN gels was tremendously increased only by chelating several mmol/L zinc ions,which was shown to firmly lock the temporary shape of the gel. Extraction of zincions by complexing agent could facilitate the recovery of permanent shape, and thememory behavior was reversible. The PVI-AN hydrogels supported the growth ofL929cells. The cells-seeded flat hydrogel sheet was folded into a temporary tubularscaffold and fixed in culture medium containing5mmol/L zinc ions. After unfoldingthe tube, the exposed L929cells were shown to adhere well on the surface of gel. It isanticipated that this cells-loaded SM hydrogel could be fixed to a desired shape invitro by small amounts of zinc ions for a potential implantable tissue engineeringscaffold.