Fast gelling and non-swellable photopolymerized poly (vinyl alcohol) hydrogels with high strength

Despite their great potential in biomedical applications, the use of hydrogels has been severely limited by their swelling property and weak strength under physiological conditions. Herein, we developed nonswelling and high-strength hydrogels by a facile one-step thiol-acrylate photopolymerization of methacrylated poly (vinyl alcohol) and thiol-terminated poly (vinyl alcohol) for the first time. The hydrogels can gel rapidly within 7 s in this approach. By controlling crosslinking density and hydrophilic/hydrophobic balance of cross-linking hydrogel networks, the properties of hydrogels can be tunable and can even exhibit an excellent nonswelling behaviour under physiological conditions. Notably, the outstanding mechanical property with a compressive strength of 7.0 MPa at ~95% strain as well as no damage through compressive stress–strain tests in the allowable scope of tensile tester can also be achieved. Moreover, the hydrogel is non-toxic to L929 cells, which is favorable for promising biomedical applications as implants and tissue engineering scaffolds.