Compositions for use as a low-swelling tissue sealant are disclosed. The compositions include first and second precursor molecules, wherein the first precursor molecule is a polyoxyethylene homopolymer having at least two nucleophilic groups or a polyoxyethylene-polyoxypropylene block copolymer having at least two nucleophilic groups and the second precursor molecule is a polyoxyethylene-polyoxypropylene block copolymer having at least two electrophilic groups. Biomaterials for use as a low-swelling tissue sealant, methods of making such biomaterials, devices for applying a biomaterial to a tissue of a patient, methods of sealing a tissue of a patient, and kits also are disclosed.