Medical devices and methods of making the same

• US 7,967,854 B2
• Filed: 02/11/2010
• Issued: 06/28/2011
• Est. Priority Date: 10/02/2002
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Schmidt, Karl Morris, Chandrasekaran, Verivada, Molina, Christopher Torres
• Primary Examiner(s): Barr; Michael
• Assistant Examiner(s): BOWMAN, ANDREW J
• Application Number:
  US12/703,838
• Publication Number:
  US 20100174360A1
• Time in Patent Office: 502 Days
• Field of Search: 623/1.34
• US Class Current: 623/1.34
• 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 tubular member defined by struts and openings, the tubular member including at least a first portion comprising an alloy of two or more elements, the alloy having a concentration gradient of at least one radiopaque element within the alloy, the first portion defining an outer surface of the tubular member, wherein the concentration of the at least one radiopaque element increases as a function of distance from the outer surface.

2. The stent of claim 1, wherein the concentration gradient varies substantially linearly along a thickness of the first portion.

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

4. The stent of claim 1, wherein the at least one radiopaque element is selected from a group consisting of gold, platinum, palladium, and tantalum.

5. The stent of claim 1, wherein the first portion is formed of an alloy comprising the at least one radiopaque element and a second element.

6. The stent of claim 1, wherein the member further includes a second portion disposed inwardly of the first portion, the second portion being more radiolucent than the first portion.

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

20. The stent of claim 1, wherein the radiopaque material is gold and the at least one additional element is titanium.

7. A stent, comprising:

a tubular member defined by struts and openings 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 an alloy of two or more elements, the alloy having a concentration gradient of at least one radiopaque element within the alloy, wherein the concentration of the at least one radiopaque element increases as a function of distance from the outer surface

an outer layer of the second portion having a lower oxidation potential than an oxidation potential of an inner layer of the second portion.

8. The stent of claim 7, wherein the second portion is capable of attenuating an incident X-ray beam by more than about 70%.

9. The stent of claim 7, wherein the at least one radiopaque element is selected from the group consisting of gold, platinum, palladium, and tantalum.

10. The stent of claim 7, wherein the alloy includes a second element is selected from the group consisting of titanium, niobium, palladium, chromium, and silicon.

11. The stent of claim 7, wherein the first portion comprises a material selected from the group consisting of stainless steel and a nickel-titanium alloy.

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

13. The stent of claim 7, wherein the first portion contacts the second portion.

14. The stent of claim 7, wherein the first and second portions have different compositions.

15. The stent of claim 7, further comprising a polymeric layer on the member.

16. The stent of claim 7, further comprising a drug-releasing layer on the member.

17. A stent, comprising:

a tubular member defined by struts and openings, the tubular member having at least a first portion including

a first layer comprising a radiopaque material, and

a second layer comprising an alloy of the radiopaque material and at least one additional element, the second layer defining an outer surface of the member, the second layer having a lower oxidation potential than an oxidation potential of the first layer, wherein the alloy of the second layer has concentration gradient of the radiopaque material that varies substantially linearly along a thickness of the second layer.

18. The stent of claim 17, wherein the radiopaque material comprises gold and the at least one additional element is titanium.