The present invention provides a biocompatible prepolymer comprising hydrophilic and hydrophobic segments, wherein the hydrophobic segments have at least one ethylenically unsaturated functional group and at least 5% of the segments have two or more ethylenically unsaturated functional groups and water. The invention further provides a biocompatible prepolymer composition comprising hydrophilic and hydrophobic prepolymers, wherein at least one of the hydrophobic prepolymers has at least one ethylenically unsaturated functional group and at least 5% of the prepolymers have two or more ethylenically unsaturated functional groups and water. The invention further provides use of the prepolymer or prepolymer compositions of the invention in biomedical applications such as tissue engineering, as bone substitutes or scaffolds, and in wound treatment.