Medical device formed of silicone-polyurethane

• US 20020187288A1
• Filed: 06/11/2001
• Published: 12/12/2002
• Est. Priority Date: 06/11/2001
• Status: Abandoned Application

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Lim, Florencia, Simhambhatla, Murthy V., Buchko, Christopher J., Shah, Ashok A.
• Application Number:
  US09/879,023
• Publication Number:
  US 20020187288A1
• Time in Patent Office: Days
• US Class Current: 428/35.2
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 29/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 29/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: Y10T 428/1334 Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/139 Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

A medical device, and particularly an intracorporeal device for therapeutic or diagnostic use, comprising a silicone polyurethane. One embodiment of the invention is a medical device having a body formed of melt process extruded, porous silicone polyurethane material. In a method of the invention, the silicone polyurethane is combined with a porogen and then melt process extruded into a desired shape such as a tubular body. The porogen is then extracted from the extrudate, to form the extruded, melt processed, porous silicone polyurethane tubular body. The medical device, such as a stent cover, vascular graft, or catheter balloon, formed of the silicone polyurethane has excellent biostability, strength, and flexibility.

Claims

1. A medical device or component thereof, comprising a body formed of melt process extruded, porous silicone polyurethane material.

2. The medical device or component thereof of claim 1 wherein the porosity of the silicone polyurethane material is about 20% to about 90% by weight of the material.

3. The medical device or component thereof of claim 1 wherein the porosity of the silicone polyurethane material is about 50% or less by weight of the material.

4. The medical device or component thereof of claim 1 wherein the body comprises a tube having a wall thickness of about 40 μ

m to about 2000 μ

m.

5. The medical device or component thereof of claim 4 wherein the wall of the body is fluid permeable.

6. The medical device or component thereof of claim 1 wherein the silicone polyurethane is selected from the group consisting of polyether silicone polyurethane, and polycarbonate silicone polyurethane.

7. The medical device or component thereof of claim 1 wherein the medical device or component thereof is selected from the group consisting of a stent cover, a vascular graft, a pacemaker lead cover, and a catheter balloon.

8. The medical device or component thereof of claim 1 wherein the medical device component is a stent cover including a therapeutic or diagnostic agent releasably contained within the silicone polyurethane material.

9. A stent cover formed at least in part of a silicone polyurethane material.

10. A stent cover, comprising a body formed of melt process extruded, porous silicone polyurethane material.

11. The stent cover of claim 10 wherein the silicone polyurethane material has a porosity of about 20% to about 90% by weight of the material.

12. The stent cover of claim 10 wherein the silicone polyurethane material has a porosity of about 50% or less by weight of the material.

13. The stent cover of claim 10 having a wall thickness of about 40 μ

m to about 2000 μ

m.

14. The stent cover of claim 10 wherein the silicone polyurethane material has a uniform porosity.

18. The method of claim 17 wherein (b) comprises heating the combined polymeric material and porogen so that the polymeric material is molten.

19. The method of claim 17 wherein the medical device component is a stent cover, and the combined polymeric material and porogen is melt process extruded into a tubular body.

20. The method of claim 17 wherein the porogen is an inorganic salt, and the polymeric material and porogen are combined by compounding in an extruder.

21. The method of claim 17 wherein extracting the porogen comprises dissolving the porogen, to produce the extruded, melt processed, porous silicone polyurethane part having a porosity of about 20% to about 90% by weight of the material.

15. A medical device component selected from the group consisting of a pacemaker lead cover and a catheter balloon, formed at least in part of melt process extruded, porous silicone polyurethane material.

16. A medical device or component thereof, comprising a body formed of melt process extruded, porous silicone polyurethane material, the body being formed by a process comprising:

a) combining a silicone polyurethane polymeric material with a porogen;

b) melt process extruding the combined polymeric material and porogen into a tubular body formed of the polymeric material and porogen; and

c) extracting the porogen from the tubular body, to form the melt process extruded, porous silicone polyurethane body.

17. A method of making a medical device or component thereof having at least a part formed of a silicone polyurethane material, comprising

a) combining a silicone polyurethane polymeric material with a porogen;

b) melt process extruding the combined polymeric material and porogen to form an extrudate; and

c) extracting the porogen from the extrudate, to form a melt process extruded, porous silicone polyurethane part.