Medical devices and methods of making the same

• US 20040068315A1
• Filed: 07/29/2003
• Published: 04/08/2004
• Est. Priority Date: 10/02/2002
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Schmidt, Karl Morris, Chandrasekaran, Verivada, Molina, Christopher Torres
• Granted Patent: US 7,297,157 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• 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 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2250/0032 differing in radiographic density
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque
• CPC Class Codes: C23C 14/16 on metallic substrates or on substrates of boron or silicon
• CPC Class Codes: C23C 14/46 by ion beam produced by an external ion source
• CPC Class Codes: C23C 28/00 Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
• CPC Class Codes: C23C 28/021 including at least one metal alloy layer
• CPC Class Codes: C23C 28/023 only coatings of metal elements only
• CPC Class Codes: C23C 28/028 Including graded layers in composition or in physical properties, e.g. density, porosity, grain size
• CPC Class Codes: C23C 28/321 with at least one metal alloy layer
• CPC Class Codes: C23C 28/322 only coatings of metal elements only
• CPC Class Codes: C23C 28/325 with layers graded in composition or in physical properties
• CPC Class Codes: C23C 28/34 : including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
• CPC Class Codes: C23C 28/341 : with at least one carbide layer
• CPC Class Codes: C23C 28/345 : with at least one oxide layer
• CPC Class Codes: C23C 28/36 : including layers graded in composition or physical properties
• CPC Class Codes: C23C 28/42 : characterized by the composition of the alternating layers
• CPC Class Codes: C23C 8/10 : Oxidising
• CPC Class Codes: C25D 5/48 : After-treatment of electroplated surfaces
• CPC Class Codes: Y10T 428/12 : All metal or with adjacent metals
• CPC Class Codes: Y10T 428/12771 : Transition metal-base component
• CPC Class Codes: Y10T 428/2995 : Silane, siloxane or silicone coating
• CPC Class Codes: Y10T 428/31544 : Addition polymer is perhalogenated
• CPC Class Codes: Y10T 428/31551 : Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31573 : Next to addition polymer of ethylenically unsaturated monomer
• CPC Class Codes: Y10T 428/31576 : Ester monomer type [polyvinylacetate, etc.]
• CPC Class Codes: Y10T 428/31678 : Of metal
• CPC Class Codes: Y10T 428/31692 : Next to addition polymer from unsaturated monomers

Abstract

An endoprosthesis, such as a stent, having a layer that can enhance the biocompatibility of the endoprosthesis, and methods of making the endoprosthesis are disclosed.

Claims

1. A stent, comprising:

a member including

a first portion; and

a second portion disposed outwardly of the first portion, the second portion being more radiopaque than the first portion and having

a first layer including a radiopaque material, and

a second layer defining an outer surface of the member and including the radiopaque material and a second material.

2. The stent of claim 1, wherein the second layer comprises an alloy of the radiopaque material and the second material.

3. The stent of claim 1, wherein the radiopaque material is capable of attenuating an incident X-ray bean by more than about 70%.

4. The stent of claim 1, wherein the radiopaque material is selected from the group consisting of gold, platinum, palladium, and tantalum.

5. The stent of claim 1, wherein the second material is selected from the group consisting of titanium, chromium, palladium, niobium, and silicon.

6. The stent of claim 1, wherein the first portion comprises a material selected from the group consisting of stainless steel and nickel-titanium alloy.

7. The stent of claim 1, wherein the first portion is the innermost portion of the member.

8. The stent of claim 1, wherein the first portion contacts the second portion.

9. The stent of claim 1, further comprising a third portion between the first portion and the second portion.

10. The stent of claim 1, further comprising a polymeric layer on the member.

11. The stent of claim 1, further comprising a drug-releasing layer on the member.

12. A stent, comprising:

a member including

a first portion having

a first layer including a radiopaque material, and

a second layer defining an outer surface of the member and including the radiopaque material and a second material.

13. A stent, comprising:

a member having

a first portion; and

a second portion disposed outwardly of the first portion, the second portion being more radiopaque than the first layer and including

a first layer comprising a radiopaque material, and

a second layer comprising the radiopaque material and defining an outer surface of the member, the second layer having a lower oxidation potential than an oxidation potential of the first layer.

14. The stent of claim 13, wherein the radiopaque material is capable of attenuating an incident X-ray beam by more than about 70%.

15. The stent of claim 13, wherein the radiopaque material is selected from the group consisting of gold, platinum, palladium, and tantalum.

16. The stent of claim 13, wherein the second layer comprises an alloy of the radiopaque material and a second material.

17. The stent of claim 13, wherein the second material is selected from the group consisting of titanium, niobium, palladium, chromium, and silicon.

18. The stent of claim 13, wherein the first portion comprises a material selected from the group consisting of stainless steel and a nickel-titanium alloy.

19. The stent of claim 13, wherein the first portion is the innermost portion of the member.

20. The stent of claim 13, wherein the first portion contacts the second portion.

21. The stent of claim 13, wherein the first and second portions have different compositions.

22. The stent of claim 13, further comprising a polymeric layer on the member.

23. The stent of claim 13, farther comprising a drug-releasing layer on the member.

24. A stent, comprising:

a member having a first portion including

a first layer comprising a radiopaque material, and

a second layer comprising the radiopaque material and defining an outer surface of the member, the second layer having a lower oxidation potential than an oxidation potential of the first layer.

25. A stent, comprising:

a member including a first portion having a concentration gradient of a radiopaque material, the first portion defining an outer surface of the member.

26. The stent of claim 25, wherein the concentration of the radiopaque material increases as a function of distance from the outer surface.

27. The stent of claim 25, wherein the concentration gradient varies substantially linearly along a thickness of the first portion.

28. The stent of claim 25, wherein the radiopaque material is capable of attenuating an incident X-ray beam by more than about 70%.

29. The stent of claim 25, wherein the radiopaque material is selected from a group consisting of gold, platinum, palladium, and tantalum.

30. The stent of claim 25, wherein the first portion is formed of an alloy comprising the radiopaque material and a second material.

31. The stent of claim 25, wherein the member further includes a second portion disposed inwardly of the first portion, the second portion being more radiolucent than the first portion.

32. A method of making a stent including a member, the method comprising:

forming an outer layer on the member, the outer layer comprising a radiopaque material and a second material; and

oxidizing a portion of the outer layer.

33. The method of claim 32, wherein oxidizing the portion comprises forming an oxide from the outer layer.

34. The method of claim 32, wherein oxidizing the portion comprises forming a nitride from the outer layer.

35. The method of claim 32, further comprising forming a radiopaque layer comprising the radiopaque material.

36. The method of claim 32, wherein the outer layer is formed with a compositional gradient.

37. The method of claim 32, wherein the outer layer is formed by a process selected from the group consisting of physical vapor deposition, chemical vapor deposition, and electrodeposition.

38. The method of claim 32, wherein oxidizing the portion of the outer layer is performed by electropolishing.

39. The method of claim 32, wherein oxidizing the portion of the outer layer is performed by heating the outer layer in an oxidizing environment.

40. The method of claim 32, wherein oxidizing the portion of the outer layer is performed by ion implanting oxygen in the outer layer and heating the outer layer.

41. The method of claim 32, further comprising forming a polymeric layer on the outer layer.

42. The method of claim 32, further comprising forming a drug-releasing layer on the outer layer.