Patent ID: 8303651
Filing Date: 2012-11-06
Classification: A61L

Abstract:
1. A stent for delivery of a therapeutic agent, comprising: a substrate; a polymer coating on the substrate that substantially reduces the rate of release of the therapeutic agent, the polymer having a crystalline structure with a crystallinity of not less than about 25%, wherein the polymer is capable of significantly maintaining the crystalline structure while the therapeutic agent is released from the stent such that the aqueous environment to which the stent is exposed subsequent to the implantation of the stent does not significantly convert the crystalline structure of the polymer to an amorphous structure such that the crystallinity of the polymer is not less than about 25% when exposed to the aqueous environment subsequent to the implantation of the stent, wherein the polymer having a crystalline structure is selected from a group consisting of fluoroethylene-alkyl vinyl ether copolymer, low density linear polyethylenes having high molecular weights, ethylene-olefin copolymers, styrene-ethylene-styrene block copolymers, styrene-butylene-styrene block copolymers, styrene-ethylene/butylene-styrene block copolymers, styrene-butadiene-styrene block copolymers, ethylene-anhydride copolymers, styrenic block copolymers, ethylene methacrylic acid copolymers, polyurethanes with a polydimethylsiloxane soft segment, and nylon 6; and a primer layer ormed on a surface of the substrate, wherein the polymer coating is formed over the primer layer, and wherein the primer layer acts as an adhesive tie between the polymer coating and the surface of the stent.