POLYMER COATING FOR MEDICAL DEVICES

The present invention relates to a coating for a medical device having a body fluid-contacting surface for contacting blood or other body fluids, the coating comprising: a silane derivative layer covalently bonded to the body fluid-contacting surface of the medical device, said silane derivative layer containing hydroxyl or amino functional groups; a lactone polymer layer polymerized on the hydroxyl or amino functional groups of the silane derivative layer through in-situ ring opening graft polymerization of lactone monomers, said polymerization initiated by said hydroxyl or amino functional groups of the silane derivative layer; at least one polyester polymer layer comprising one or more biologically active agents deposited on the lactone polymer layer, wherein at least the first layer of the at least one polyester polymer layer is chemically compatible with the lactone polymer layer to allow for entanglement of the polyester polymer chains with the lactone polymer chains; and optionally at least one polymer layer deposited on said at least one polyester polymer layer forming a skin or barrier layer.