Medical devices, and particularly intracorporeal devices for therapeutic or diagnostic uses, having a component chemically modified by plasma polymerization. The medical device comprises a substrate with a plasma polymerized functionality bonded to a surface of at least a section thereof. The plasma polymerized film on a first component of the medical device allows for bonding an agent or a second component to the first component. In one embodiment, the plasma polymerized film facilitates fusion or adhesive bonding of a first component to a second component formed of a material which is dissimilar to, incompatible with, or otherwise not readily bondable to the substrate material of the first component. In another embodiment, a bioactive agent is bonded to the plasma polymerized film on the component, for presenting or delivering the bioactive agent within a body lumen of the patient.