Porous coatings for biomedical implants

• US 20060004466A1
• Filed: 06/28/2005
• Published: 01/05/2006
• Est. Priority Date: 06/28/2004
• Status: Active Grant

• Current Assignee: Isoflux Incorporated
• Original Assignee: Isoflux Incorporated
• Inventors: Glocker, David A., Romach, Mark M.
• Granted Patent: US 8,894,824 B2
• Time in Patent Office: Days
• US Class Current: 623/23.550
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2002/30929 having at least two superposed coatings
• CPC Class Codes: A61F 2310/00407 Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00449 Coating made of chromium or Cr-based alloys
• CPC Class Codes: A61F 2310/00485 Coating made of zirconium or Zr-based alloys
• CPC Class Codes: A61F 2310/00497 Coating made of molybdenum or Mo-based alloys
• CPC Class Codes: A61F 2310/00544 Coating made of tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/0088 Coating made of titanium nitride
• CPC Class Codes: A61F 2310/0097 Coating or prosthesis-covering structure made of pharmaceutical products, e.g. antibiotics
• CPC Class Codes: A61L 27/306 Other specific inorganic materials not covered by A61L27/303 - A61L27/32
• CPC Class Codes: C23C 14/225 Oblique incidence of vaporised material on substrate

Abstract

A medical implant has a microscopically rough outer coating that serves to bond the implant to animal tissue. The coating is applied to the implant by physical vapor deposition. The coating preferable is applied via a generally oblique coating flux or a low energy coating flux. In some embodiments, the coating has pores. The pores can contain a drug, which can diffuse over a period of time. The coating may be partially nonporous to protect the implant from corrosion. The coating can have an outer porous layer that can bond with animal tissue easily.

Claims

1. A biomedical device comprising:

an implant; and

a biomedically compatible, microscopically rough coating applied to the implant via physical vapor deposition.

2. The device of claim 1 wherein the coating has surface features having a size between 10 nm and 1000 nm.

3. The device of claim 1 wherein the coating has surface features and the surface features vary in size.

4. The device of claim 1 wherein the coating comprises one of the group of tantalum, titanium nitride, titanium, molybdenum, chromium and zirconium.

5. The device of claim 1 where in the coating is configured to serve as a bonding layer between the implant and natural bone or tissue.

6. The device of claim 1 wherein the physical vapor deposition comprises one of the group of sputtering, cathodic arc deposition or thermal evaporation.

7. The device of claim 1 wherein the coating is applied to the implant via one of a generally oblique coating flux or a low energy coating flux.

8. The device of claim 1 wherein the coating has pores.

9. The device of claim 8 further comprising a drug within the pores.

10. The device of claim 1 further comprising a second coating applied to the implant

11. The device of claim 10 wherein the second coating is applied directly to the implant and the porous coating is applied to the second coating.

12. The device of claim 11 wherein the second coating protects the implant from corrosion.

13. The device of claim 11 wherein the second coating in nonporous.

14. The device of claim 1 wherein the coating has a thickness between 0.1 and 10 micrometers.

15. A process for depositing a coating on a biomedical implant comprising the steps of:

maintaining a background pressure of gas in a sputter coating system containing at least one sputter target;

applying a voltage to the target to cause sputtering; and

sputtering for a period of time to produce a microscopically rough coating on the implant.

16. The process of claim 15 wherein the coating has surface features having a size between 10 nm and 1000 nm.

17. The process of claim 15 wherein the coating has surface features and the surface features vary in size.

18. The process of claim 15 wherein the coating comprises one of the groups of tantalum, titanium nitride, titanium, molybdenum, chromium and zirconium.

19. The process of claim 15 where in the coating is configured to serve as a bonding layer between the implant and animal tissue.

20. The process of claim 15 wherein the coating is applied to the implant via one of a generally oblique coating flux or a low energy coating flux.

21. The process of claim 15 further comprising a second coating applied to the implant

22. The process of claim 21 wherein the second coating is applied directly to the implant.

23. The process of claim 22 wherein the second coating protects the implant from corrosion.

24. The device of claim 22 wherein the second coating in nonporous.

25. The process of claim 15 wherein the coating has a thickness between 0.1 and 10 micrometers.

26. The process of claim 15 wherein the coating comprises at least one porous portion and at least one nonporous portion.

27. The process of claim 26 wherein the porous portion coats the nonporous portion.

28. The process of claim 15 wherein the coating has pores.

29. The process of claim 28 further comprising a drug within the pores.