Fast, oxygen-tolerant RAFT polymerization of hydrogels

Abstract Synthetic hydrogels are an attractive platform for cell culture, as they are water-rich, and they can often be used to encapsulate cells within a 3D matrix under the right chemical conditions. Many hydrogels form via free-radical polymerization in the presence of initiating species under ultraviolet (UV) light. The combination of free radicals and UV light during polymerization can lead to decreased viability and cellular stress. Here, we demonstrate a photoiniferter strategy to polymerize hydrogel networks without exogenous initiators and UV light. We demonstrate the formation of soft hydrogels with xanthate functional polymers by using visible light. Importantly, polymerization proceeds equally well under nitrogen and under ambient conditions with a range of monomers. We suggest this process as a way to diversify monomer choice for synthetic hydrogel development in the absence of UV light and free-radical initiators.