6.2 Hybridization of Thiol–Ene Chemistry Hydrogels for Biomedical Applications

Light-triggered thiol–ene polymerization is a powerful tool for synthesizing hydrogels that are aimed to be applied in situ or used as 3D scaffolds. Thiol–ene reactions are a class of click transformations that involve free-radical-mediated addition of electron-rich thiol groups to electron-poor carbon–carbon double bonds. When tuned with homopolymerization of the carbon–carbon double bonds, the resultant hydrogel properties can be finely adjusted. In this review, commonly used methods for modifying polymers with thiol groups or double bonds are discussed, and strategies to overcome flaws in thiol–ene hydrogels are provided. Emphasis is given to the application and outlook of thiol–ene cross-linked hydrogels.