The present disclosure relates to compositions A composition comprising a polymerization product of an anionic polysaccharide, a diisocyanate, and a linker, wherein the linker comprises i) an ether group, an ester group, or a combination thereof and, ii) a chain extender comprising a hydroxyl group, a thiol group, an amine group, or a combination thereof. The disclosure further relates to medical devices comprising the aforementioned compositions, and to methods of using the compositions and devices. More particularly, the compositions, devices and methods described herein are useful for preventing protein adhesions in vivo, particularly the Vroman effect.