Vascular and endoluminal stents with improved coatings

• US 6,387,121 B1
• Filed: 08/08/2000
• Issued: 05/14/2002
• Est. Priority Date: 10/21/1996
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: InFlow Dynamics, Inc. (Boston Scientific Corporation)
• Inventors: Alt, Eckhard
• Primary Examiner(s): Milano, Michael J.
• Assistant Examiner(s): Bui, Vy Q.
• Application Number:
  US09/634,667
• Time in Patent Office: 644 Days
• Field of Search: 623/1.1, 623/1.11, 623/1.12, 623/1.13, 623/1.14, 623/1.15, 623/1.16, 623/1.17, 623/1.18, 623/1.19, 623/1.2, 623/1.21, 623/1.22, 623/1.44, 623/1.45, 623/1.46, 606/191, 606/194, 606/198
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2210/0095 radioactive
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2310/00568 Coating made of gold or Au-based alloys
• CPC Class Codes: A61F 2310/00598 Coating or prosthesis-covering structure made of compounds based on metal oxides or hydroxides
• CPC Class Codes: A61F 2310/0088 Coating made of titanium nitride

Abstract

A stent has a tubular metal base adapted to be expanded from a first vessel-navigable diameter to a larger second vessel-deployed diameter; a thin, continuous intermediate layer of noble metal or alloy thereof selected from a group consisting of niobium, zirconium, titanium and tantalum, overlying and tightly adherent to an exposed surface area of the tubular metal base; and a biocompatible outer layer of iridium oxide overlying and adherent to the intermediate layer. The outer layer has a relatively rough surface with interstices into which beneficial drugs or other substances or agents may be infused, with or without a biodegradable carrier, to preclude occlusion from restenosis or thrombosis during the acute stage following deployment of the stent.

Claims

1. A stent, comprising a tubular metal base adapted to be expanded from a first vessel-navigable diameter to a larger second vessel-deployed diameter;

a thin, continuous intermediate layer of noble metal or alloy thereof selected from a group consisting of niobium, zirconium, titanium and tantalum, overlying and tightly adherent to an exposed surface area of said tubular metal base; and

a biocompatible outer layer of iridium oxide overlying and adherent to said intermediate layer.

2. The stent of claim 1, wherein the composite thickness of the wall of said tubular metal base, and said intermediate and outer layers thereon is less than approximately 60 μ

m.

3. The stent of claim 1, wherein said intermediate layer is an alloy composed of niobium and zirconium.

4. The stent of claim 3, wherein the amount of zirconium in said intermediate layer alloy is in a range from about 1% to about 3% by weight of the total intermediate layer.

5. The stent of claim 1, wherein said intermediate layer is an alloy composed of titanium and tantalum.

6. The stent of claim 5, wherein the amount of tantalum in said intermediate layer alloy is in a range from about 30% to about 40% by weight.

7. The stent of claim 1, wherein said outer layer has a rough surface with interstices thereof at least partially filled with a substance selected to enhance the compatibility of the stent in a body in which said stent is to be implanted.

8. The stent of claim 1, wherein said outer layer has a rough surface with interstices thereof at both interior and exterior surfaces of said stent at least partially filled with drugs selected to inhibit closure of a central lumen at a site in the body at which said stent is to be implanted.

9. The stent of claim 8, wherein said drugs are contained within a biodegradable carrier for release of said drugs during disintegration of the carrier.

10. The stent of claim 1, wherein said outer layer has a rough surface with interstices thereof at both interior and exterior surfaces of said stent at least partially filled with substances that genetically interfere with cells at a site in the body at which said stent is to be implanted.