Biodegradable vascular device with buffering agent

• US 7,803,182 B2
• Filed: 05/28/2004
• Issued: 09/28/2010
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: Cardinal Health Switzerland 515 GmbH (Cardinal Health, Inc.)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Dave, Vipul Bhupendra, Landau, George, Patel, Premal
• Primary Examiner(s): Stewart; Alvin J
• Application Number:
  US10/856,459
• Publication Number:
  US 20050278015A1
• Time in Patent Office: 2,314 Days
• Field of Search: 623 138- 154, 623/1.11, 623/1.15
• US Class Current: 623/1.38
• CPC Class Codes: A61L 2300/604 Biodegradation
• CPC Class Codes: A61L 31/129 containing macromolecular fillers
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence

Abstract

A vascular or cardiovascular medical device for placement at a site in a patient'"'"'s body and for controlling pH levels at the site in the patient'"'"'s body includes one or more structural components made of a biodegradable and/or bioabsorbable material, or alternatively, a coating thereon made of a biodegradable and/or bioabsorbable material. A buffering agent is provided on or in the biodegradable and/or bioabsorbable material and the buffering agent is dispersed from the biodegradable and/or bioabsorbable material in response to hydrolysis of the biodegradable and/or bioabsorbable material. Additionally, the vascular or cardiovascular medical device can include a drug that is included with the biodegradable and/or bioabsorbable material. The vascular or cardiovascular medical device can also be a stent or a valve.

Claims

1. A vascular or cardiovascular medical device for placement at a site in a patient'"'"'s body and for controlling pH levels at the site in the patient'"'"'s body, the device comprising:

one or more structural components made of a first biodegradable and/or bioabsorbable material; and

a particle made of a second biodegradable and/or bioabsorbable material encapsulating a buffering agent, the buffering agent being dispersed from the second biodegradable and/or bioabsorbable material as the second biodegradable and/or bioabsorbable material degrades, in response to a reduction in the pH level at the site in the patient'"'"'s body resulting from the hydrolysis of the first biodegradable and/or bioabsorbable material.

2. The vascular or cardiovascular medical device according to claim 1, wherein the first biodegradable and/or bioabsorbable material is a bulk erodible polymer that is either a homopolymer, a copolymer or a blend of polymers.

3. The vascular or cardiovascular medical device according to claim 2, wherein the bulk erodible polymer is a polyester.

4. The vascular or cardiovascular medical device according to claim 3, wherein the polyester belongs to the poly (alpha-hydroxy acids) group.

5. The vascular or cardiovascular medical device according to claim 4, wherein the polyester is an aliphatic polyester.

6. The vascular or cardiovascular medical device according to claim 5, wherein the aliphatic polyester is selected from the group consisting of poly (lactic acid), poly(glycolic acid), poly (caprolactone), poly(p-dioxanone) and poly (trimethylene carbonate).

7. The vascular or cardiovascular medical device according to claim 2, wherein the bulk erodible polymer is an amino acid derived polymer selected from the group consisting of poly (iminocarbonates), phosphorous containing polymers, poly (phosphazenes), poly (phosphoesters) and poly (ester amide).

8. The vascular or cardiovascular medical device according to claim 1, further comprising a drug with the first biodegradable and/or bioabsorbable material or the second biodegradable and/or bioabsorbable material.

9. The vascular or cardiovascular medical device according to claim 1, wherein the buffering agent is selected from the group consisting of calcium hydroxyapatite, carbonated apatite, tricalcium phosphate, calcium carbonate, sodium bicarbonate, calcium phosphates, carbonated calcium phosphates, magnesium hydroxide, amine monomers, and lactate dehydrogenase.

10. The vascular or cardiovascular medical device according to claim 1, wherein the buffering agent is dispersed from the second biodegradable and/or bioabsorbable material at pH <

7.4.

11. The vascular or cardiovascular medical device according to claim 10, wherein the buffering agent is dispersed from the second biodegradable and/or bioabsorbable material at pH ranging from about 3 to about 6.

12. The vascular or cardiovascular medical device according to claim 11, wherein the buffering agent is dispersed from the second biodegradable and/or bioabsorbable material at pH of about 5.

13. The vascular or cardiovascular medical device according to claim 10, wherein the buffering agent raises pH at the site after being dispersed from the second biodegradable and/or bioabsorbable material.

14. The vascular or cardiovascular medical device according to claim 13, wherein the buffering agent raises pH to about 7.4 at the site after being dispersed from the second biodegradable and/or bioabsorbable material.

15. The vascular or cardiovascular medical device according to claim 1, wherein the device is a stent.

16. The vascular or cardiovascular medical device according to claim 1, wherein the device is a valve.

17. The vascular or cardiovascular medical device according to claim 1, wherein the particle is a microparticle.

18. The vascular or cardiovascular medical device according to claim 1, wherein the particle is a nanoparticle.

19. A vascular or cardiovascular medical device for placement at a site in a patient'"'"'s body and for controlling pH levels at the site in the patient'"'"'s body, the device comprising:

one or more structural components having a coating thereon, the coating made of a first biodegradable and/or bioabsorbable material; and

a particle made of a second biodegradable and/or bioabsorbable material encapsulating a buffering agent, the buffering agent being dispersed from the second biodegradable and/or bioabsorbable material as the second biodegradable and/or bioabsorbable material degrades, in response to a reduction in the pH level at the site in the patient'"'"'s body resulting from the hydrolysis of the first biodegradable and/or bioabsorbable material.

20. The vascular or cardiovascular medical device according to claim 19, wherein the first biodegradable and/or bioabsorbable material is a bulk erodible polymer that is either a homopolymer, a copolymer or a blend of polymers.

21. The vascular or cardiovascular medical device according to claim 20, wherein the bulk erodible polymer is a polyester.

22. The vascular or cardiovascular medical device according to claim 21, wherein the polyester belongs to the poly (alpha-hydroxy acids) group.

23. The vascular or cardiovascular medical device according to claim 22, wherein the polyester is an aliphatic polyester.

24. The vascular or cardiovascular medical device according to claim 23, wherein the aliphatic polyester is selected from the group consisting of poly (lactic acid), poly (glycolic acid), poly (caprolactone), poly (p-dioxanone) and poly (trimethylene carbonate).

25. The vascular or cardiovascular medical device according to claim 20, wherein the bulk erodible polymer is an amino acid derived polymer selected from the group consisting of poly (iminocarbonates), phosphorous containing polymers, poly (phosphazenes), poly (phosphoesters) and poly (ester amide).

26. The vascular or cardiovascular medical device according to claim 19, further comprising a drug with the first biodegradable and/or bioabsorbable material or the second biodegradable and/or bioabsorbable material.

27. The vascular or cardiovascular medical device according to claim 19, wherein the buffering agent is selected from the group consisting of calcium hydroxyapatite, carbonated apatite, tricalcium phosphate, calcium carbonate, sodium bicarbonate, calcium phosphates, carbonated calcium phosphates, magnesium hydroxide, amine monomers, and lactate dehydrogenase.

28. The vascular or cardiovascular medical device according to claim 19, wherein the buffering agent is dispersed from the second biodegradable and/or bioabsorbable material at pH <

7.4.

29. The vascular or cardiovascular medical device according to claim 28, wherein the buffering agent is dispersed from the second biodegradable and/or bioabsorbable material at pH ranging from about 3 to about 6.

30. The vascular or cardiovascular medical device according to claim 29, wherein the buffering agent is dispersed from the second biodegradable and/or bioabsorbable material at pH of about 5.

31. The vascular or cardiovascular medical device according to claim 28, wherein the buffering agent raises pH at the site after being dispersed from the second biodegradable and/or bioabsorbable material.

32. The vascular or cardiovascular medical device according to claim 31, wherein the buffering agent raises pH to about 7.4 at the site after being dispersed from the second biodegradable and/or bioabsorbable material.

33. The vascular or cardiovascular medical device according to claim 19, wherein the device is a stent.

34. The vascular or cardiovascular medical device according to claim 19, wherein the device is a valve.

35. The vascular or cardiovascular medical device according to claim 19, wherein the particle is a microparticle.

36. The vascular or cardiovascular medical device according to claim 19, wherein the particle is a nanoparticle.