Fluoropolymer-based medical implant coating compositions

• US 8,475,844 B2
• Filed: 04/16/2009
• Issued: 07/02/2013
• Est. Priority Date: 04/16/2008
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Kocur, Gordon, Rolf, David, Lasch, James, Seethamraju, Kasyap
• Primary Examiner(s): Wax, Robert A
• Assistant Examiner(s): Tcherkasskaya, Olga V
• Application Number:
  US12/424,946
• Publication Number:
  US 20090264539A1
• Time in Patent Office: 1,538 Days
• Field of Search: None
• US Class Current: 424/487
• CPC Class Codes: A61L 2420/06 Coatings containing a mixture of two or more compounds
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: A61P 7/02 Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors
• CPC Class Codes: C08F 214/186 with non-fluorinated comonomers
• CPC Class Codes: C08F 220/10 Esters
• CPC Class Codes: C08F 2438/01 Atom Transfer Radical Polymerization [ATRP] or reverse ATRP
• CPC Class Codes: C08F 293/005 using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 27/16 Homopolymers or copolymers or vinylidene fluoride
• CPC Class Codes: C08L 33/06 of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical

Abstract

Polymers of fluorinated monomers and acrylate and alkyl acrylates are disclosed which demonstrate improved performance as coatings for implantable devices. Such coatings may, for example, be used to release a bioactive agent from the medical device. One specific application lies in drug-eluting coatings for stents.

Claims

1. A medical implant comprising a coating that comprises a copolymer composition, said copolymer composition comprising:

a fluoromonomer unit selected from the group consisting of vinylidene difluoride, hexafluoropropylene and combinations thereof; and

an acrylate monomer unit of the formula I,

2. The medical implant of claim 1, wherein the mole % of said acrylate monomer unit in the copolymer composition is 50% or lower.

3. The medical implant of claim 1, wherein the mole % of said acrylate monomer unit in the copolymer composition is selected from the group consisting of 10-20%, 10-50%, and 25-50%.

4. The medical implant of claim 1, wherein the copolymer composition has a glass transition temperature of less than 35°

C.

5. The medical implant of claim 1, wherein the copolymer composition has a glass transition temperature of less than 20°

C.

6. The medical implant of claim 1, wherein the copolymer composition comprises a random copolymer, a block copolymer, or a graft copolymer.

7. The medical implant of claim 1, wherein the acrylate monomer unit is selected from the group consisting of methylmethacrylate, ethylmethacrylate, butylmethacrylate, hexylmethacrylate, methacrylate, n-butylacrylate, ethylacrylate, and any combination thereof.

8. The medical implant of claim 1, further comprising a bioactive agent.

9. The medical implant of claim 8, wherein said bioactive agent is an antithrombotic agent.

10. The medical implant of claim 1, further comprising an additional monomer unit wherein said additional monomer unit is present at less than 10 mole % of the composition.

22. The medical implant of claim 1, wherein R¹ is other than methyl.

23. The medical implant of claim 22, wherein said copolymer composition comprises a block copolymer or a graft copolymer.

24. The medical implant of claim 1, wherein said copolymer composition comprises a block copolymer or a graft copolymer.

25. The medical implant of claim 22, wherein the an acrylate monomer unit is of formula V,

26. The medical implant of claim 1, wherein said copolymer composition does not comprise an additional acrylate monomer unit having a polar functional group selected from a carboxylate group, an amine group, an alcohol group, and amide group, a nitro group and a cyano group.

27. The medical implant of claim 1, wherein said copolymer composition comprises more than one type of acrylate monomer unit.

28. The medical implant of claim 1, selected from stents, stent-grafts, grafts, artificial heart valves, cerebrospinal fluid shunts, pacemaker electrodes, and endocardial leads.

29. The medical implant of claim 22, wherein said copolymer composition does not comprise an additional acrylate monomer unit having a polar functional group selected from a carboxylate group, an amine group, an alcohol group, and amide group, a nitro group and a cyano group.

30. The medical implant of claim 22, wherein said copolymer composition comprises more than one type of acrylate monomer unit.

31. The medical implant of claim 22, selected from stents, stent-grafts, grafts, artificial heart valves, cerebrospinal fluid shunts, pacemaker electrodes, and endocardial leads.

11. A medical implant comprising a coating that comprises a copolymer composition, said copolymer composition comprising:

a fluoromonomer unit selected from the group consisting of vinylidene difluoride, hexafluoropropylene and combinations thereof; and

,

an acrylate monomer unit of formula V,

12. The medical implant of claim 11, wherein the mole % of said acrylate monomer unit in the copolymer composition is 50% or lower.

13. The medical implant of claim 11, wherein the mole % of said acrylate monomer unit in the copolymer composition is selected from the group consisting of 10-20%, 10-50%, and 25-50%.

14. The medical implant of claim 11, having a glass transition temperature of less than 35°

C.

15. The medical implant of claim 14, having a glass transition temperature of less than 20°

C.

16. The medical implant of claim 11, wherein the copolymer composition comprises a random copolymer, a block copolymer, or a graft copolymer.

17. The medical implant of claim 11, further comprising a bioactive agent.

18. The medical implant of claim 17, wherein said bioactive agent is an antithrombotic agent.

19. The medical implant of claim 11, further comprising an additional monomer unit wherein said additional monomer unit is present at less than 10 mole % of the composition.

20. A medical implant comprising a coating that comprises a polymer blend composition, said copolymer composition comprising:

a fluoromonomer unit selected from the group consisting of vinylidene difluoride, hexafluoropropylene and combinations thereof; and

a polyacrylate having a monomer unit of the formula I,

21. The medical implant of claim 20, wherein said polymer blend further comprises a third polymer, said third polymer being substantially free of fluoromonomers and acrylate monomers.