Medical devices having polymeric nanoporous coatings for controlled therapeutic agent delivery and a nonpolymeric macroporous protective layer

摘要

An implantable or insertable medical device is provided which contains the following: (a) a substrate, (b) a therapeutic agent-containable region disposed over the substrate, (c) a nanoporous polymeric layer disposed over the therapeutic agent-containable region and (d) a macroporous non-polymeric layer disposed over the nanoporous polymeric layer. The nanoporous polymeric layer largely regulates transport of species between the therapeutic agent-containable region and the exterior of the device. The macroporous non-polymeric layer has a larger pore size than the nanoporous polymeric layer and largely serves to isolate the polymeric material from surrounding tissue during in-situ delivery of the therapeutic agents.