This invention provides implantable medical devices having at least one moiety attached to the surface capable of catalyzing a reaction in vivo. The implantable medical device has a body such as a stent with a surface adapted to be placed adjacent to a biological tissue or fluid. The body has at least one moiety attached to the surface which is capable of catalyzing a first reaction upon contacting a first substrate in the biological tissue or fluid. The moiety remains attached to the surface after the first reaction and is capable of catalyzing at least a second reaction upon contacting a second substrate. In preferred embodiments the moiety is capable of catalyzing a multitude of reactions as substrates come into contact and then leave the surface of the device.
