A material is described herein. The material includes a multi-vinylsulfone containing molecule and a multi-nucleophile containing molecule. The material can form a hydrogel from an aqueous solution with dissolved multi-vinylsulfone and a multi-nucleophile. The aqueous solution can undergo gelation with a controllable gelation time to form the hydrogel upon administration to a space in a body. The hydrogel can form in situ with controllable properties, which allow the hydrogel to be used in many biomedical applications. Examples of biomedical applications include, but are not limited to, a volume/filler expander, a storage and delivery mechanism for biologics, and as a tissue interacting surface.
