Zirconium oxide and zirconium nitride coated stents
AssigneeSmith & Nephew Richards Inc.
InventorJames A. Davidson
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Abstract
Stents fabricated from a substrate of a low modulus metal coated with blue to black zirconium oxide or zirconium nitride. The coating provides enhanced thrombogenicity, biocompatibility, blood compatibility, corrosion-resistance, friction and microfretting resistance, durability, and electrical insulation, where applicable. The coatings may be applied to low modulus metallic substrates by physical or chemical vapor deposition as well as other ion-beam assisted methods. Preferably, however, for optimizing attachment strength, the stents are fabricated from zirconium or zirconium-containing alloys and the coatings are formed by oxidizing or nitriding through an in situ method that develops a coating from and on the metal surface of the stent, without need for depositing a coating on the metal surface.
Claims12
An expandable stent for supporting a tubular conduit of a living body from collapsing inward, the stent comprising:
- (a) a radially outwardly expandable substantially cylindrical stent body of a low elastic modulus metallic composition for insertion in a tubular conduit of a living body, the stent body having a longitudinal bore therethrough for receiving a means for expanding the body radially outwardly and outer surfaces exposed to body fluid and body tissue when the stent is in use;
- (b) a corrosion-resistant, biocompatible, hemocompatible, durable, stable coating selected from the group consisting of zirconium oxides, ranging in color from blue to black, and zirconium nitrides, ranging in color from yellow to orange;
- said coating disposed on surfaces of the stent body exposed to body fluid and body tissue when the stent is in use;
- and
- (c) anchoring means for engaging the tubular conduit and anchoring the stent body in a radially outward expanded position thereby supporting the tubular conduit from collapsing inward.
Dependencies are inferred from the claim text.