ENDOPROSTHESIS COATING

• US 20090319032A1
• Filed: 06/17/2009
• Published: 12/24/2009
• Est. Priority Date: 06/18/2008
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Weber, Jan, Atanasoska, Liliana, Zoromski, Michele
• Granted Patent: US 8,449,603 B2
• Time in Patent Office: Days
• US Class Current: 623/1.390
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges

Abstract

An endoprosthesis, e.g., a stent (e.g., a drug eluting stent), that includes a porous surface and hollow elements integrated with a coating on the surface and a method of making the same are disclosed.

Claims

1. An endoprosthesis, comprising:

a surface, the surface comprising a porous structure of a first material; and

a coating of a second material, the second material defining a plurality of hollow elements.

2. The endoprosthesis of claim 1, wherein the first material is a metal.

3. The endoprosthesis of claim 1, wherein the second material is a ceramic material.

4. The endoprosthesis of claim 3, wherein the ceramic material is silicon oxide, titanium oxide, iridium oxide or a mixture thereof.

5. The endoprosthesis of claim 1, wherein the coating and hollow elements have a porous structure.

6. The endoprosthesis of claim 5, wherein the porous structure comprises a plurality of pores having a width of about 0.5 nm to about 500 nm.

7. The endoprosthesis of claim 1, wherein the hollow elements contain a drug.

8. The endoprosthesis of claim 1, wherein the porous structure of the first material comprises a plurality of pores having a width and a depth of about 1 nm to about 25 μ

m.

9. The endoprosthesis of claim 1, wherein the hollow elements are hollow spheres.

10. The endoprosthesis of claim 9, wherein the hollow spheres have an outer diameter of about 10 nm to about 5 μ

m.

11. The endoprosthesis of claim 1, wherein the coating and hollow elements have a thickness of about 1 nm to about 1 μ

m.

12. The endoprosthesis of claim 1, wherein the endoprosthesis has a body formed of the first material.

13. A method of making an endoprosthesis, the method comprising:

applying a sacrificial template to a surface;

applying a ceramic precursor over the template;

treating the precursor to form a ceramic deposit; and

removing the sacrificial template to form a hollow ceramic region.

14. The method of claim 13, further comprising providing a drug in the hollow ceramic region.

15. The method of claim 13, further comprising forming a plurality of pores on a surface, said pores having a width and a depth of about 1 nm to about 25 μ

m; and

applying said sacrificial template to said porous surface.

16. The method of claim 13, further comprising applying a polyelectrolyte layer to the sacrificial template, applying a sol-gel ceramic precursor to the polyelectrolyte and reacting the sol-gel precursor to form a ceramic gel deposit.

17. The method of claim 16, further comprising removing the polyelectrolyte and template by heating.

18. The method of claims 16 or 17, further comprising converting the ceramic gel deposit to an oxide or ceramic.

19. The method of claim 18, further comprising converting the ceramic gel deposit by firing.

20. The method of claim 16, further comprising applying a polyelectrolyte layer before applying said sacrificial template.

21. The method of claim 20, further comprising applying polyelectrolyte layers by LBL deposition.

22. The method of claim 13, further comprising loading a drug to the endoprosthesis before the coating is formed.

23. The method of claim 13, wherein the sacrificial template is a polymer particle.

24. The method of 23, wherein the particle has a size of about 10 nm to about 10 μ

m.

25. The method of 13, wherein the sacrificial template is pretreated with a polyelectrolyte to be encapsulated by a polyelectrolyte coating.