The present invention relates to modified polymer surfaces capable of releasing bioactive agents and a method for preventing cell growth on a surface. Thus, one aspect of the invention relates to a medical device comprising a device substrate having a surface, a polymer coating attached to said surface, and a bioactive agent covalently attached to said polymer coating, and wherein said bioactive agent is covalently attached to said polymer coating via at least one ester or carboxylic acid anhydride moiety sensitive to cleavage by an enzyme. Another aspect of the present invention relates to a method of inhibiting or preventing cell growth on a surface comprising modifying said surface with a polymer coating comprising a bioactive agent covalently attached to said polymer coating.
