A method for applying a coating comprising a comb-type anti-thrombotic conjugate to at least a portion of an implantable device to prevent or reduce the formation of thrombosis on the surface of the device, involves preparing a first or sub-layer of the coating by mixing a polymeric material and a biologically active agent with a solvent, thereby forming a homogeneous solution. A second or outer layer comprising a comb-type anti-thrombotic conjugate is applied over the inner drug-containing layers using, for example, a dip coating or spray coating process. Alternatively the comb-type antithrombotic conjugate may be used as a matrix material to encapsulate a pharmaceutical agent to form microspheres or nanospheres before depositing the microspheres or nanospheres onto a medical device.
