DURABLE HIGH STRENGTH POLYMER COMPOSITE SUITABLE FOR IMPLANT AND ARTICLES PRODUCED THEREFROM

• US 20120253453A1
• Filed: 04/01/2011
• Published: 10/04/2012
• Est. Priority Date: 04/01/2011
• Status: Active Grant

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: Gore Enterprise Holdings Incorporated
• Inventors: Hartman, Cody L., Walsh, Peter J., White, Charles F., Bruchman, William C., Gassler, Paul D.
• Granted Patent: US 8,961,599 B2
• Time in Patent Office: Days
• US Class Current: 623/1.24
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2/2472 Devices for testing
• CPC Class Codes: A61F 2/2475 Venous valves
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2230/00 Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61L 2430/20 for reconstruction of the heart, e.g. heart valves
• CPC Class Codes: A61L 27/025 Other specific inorganic materials not covered by A61L27/04 - A61L27/12
• CPC Class Codes: A61L 27/40 Composite materials, i.e. containing one material dispersed in a matrix of the same or different material
• CPC Class Codes: A61L 27/48 with macromolecular fillers
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: C08L 27/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers

Abstract

A thin, biocompatible, high-strength, composite material is disclosed that is suitable for use in various implanted configurations. In one aspect, the composite material maintains flexibility in high-cycle flexural applications, making it particularly applicable to high-flex implants such as heart pacing lead or heart valve leaflet. The composite material includes a porous expanded fluoropolymer membrane and an elastomer, wherein the elastomer fills substantially all of the pores of the porous expanded fluoropolymer, and the composite material comprising less than about 80% fluoropolymer by weight.

Claims

1. An implantable article for regulating blood flow direction in a human patient, said implantable article comprising:

a leaflet comprising a composite material having at least one fluoropolymer layer having a plurality of pores and an elastomer present in substantially all of the pores of the at least one fluoropolymer layer, the composite material comprising less than about 80% fluoropolymer by weight.

2. The implantable article as set forth in claim 1, wherein the composite material comprising less than about 70% fluoropolymer by weight.

3. The implantable article as set forth in claim 1, wherein the composite material comprising less than about 60% fluoropolymer by weight.

4. The implantable article as set forth in claim 1, wherein the composite material comprising less than about 50% fluoropolymer by weight.

5. The implantable article as set forth in claim 1, wherein the composite material further includes a layer of the elastomer.

6. The implantable article as set forth in claim 5, wherein the elastomer is a fluoroelastomer.

7. The implantable article as set forth in claim 6, wherein the elastomer is a TFE/PMVE copolymer.

8. The implantable article as set forth in claim 7, wherein the copolymer consists essentially of between about 40 and 80 weight percent perfluoromethyl vinyl ether and complementally 60 and 20 weight percent tetrafluoroethylene.

9. The implantable article as set forth in claim 5, wherein the fluoropolymer is PTFE.

10. The implantable article as set forth in claim 9, wherein the PTFE is ePTFE.

11. The implantable article as set forth in claim 10, wherein the at least one fluoropolymer layer has a matrix tensile strength in at least one direction greater than about 96 MPa.

12. The implantable article as set forth in claim 1, wherein the elastomer is a fluoroelastomer.

13. The implantable article as set forth in claim 12, wherein the elastomer is a TFE/PMVE copolymer.

14. The implantable article as set forth in claim 13, wherein the copolymer consists essentially of between about 40 and 80 weight percent perfluoromethyl vinyl ether and complementally about 60 and 20 weight percent tetrafluoroethylene.

15. The implantable article as set forth in claim 1, wherein the fluoropolymer is PTFE.

16. The implantable article as set forth in claim 15, wherein the PTFE is ePTFE.

17. The implantable article as set forth in claim 16, wherein the at least one fluoropolymer layer has a matrix tensile strength in at least one direction greater than about 96 MPa.

18. The implantable article as set forth in claim 1, wherein the leaflet has a thickness of less than about 350 μ

m.

19. The implantable article as set forth in claim 1, wherein the leaflet has a thickness of less than about 300 μ

m

20. The implantable article as set forth in claim 1, wherein the leaflet has a thickness of less than about 200 μ

m.

21. The implantable article as set forth in claim 1, wherein the leaflet has a thickness of less than about 100 μ

m.

22. The implantable article as set forth in claim 1, wherein the leaflet has a thickness of less than about 50 μ

m.

23. The implantable article as set forth in claim 1, wherein the leaflet has a thickness of less than about 25 μ

m.

24. The implantable article as set forth in claim 1, wherein the EOA across the implantable article for regulating blood flow direction is maintained within about 10% after about 40 million cycles.

25. The implantable article as set forth in claim 1, wherein a regurgitant fraction across the implantable article for regulating blood flow direction is maintained below about 15% after about 40 million cycles.

26. The implantable article as set forth in claim 1, wherein the leaflet is devoid of edge delamination or hole formation after about 40 million cycles.

27. A method of forming the composite material of the implantable article of claim 1, said method comprising the steps of:

dissolving an elastomer in a solvent suitable to create a solution to substantially fill the pores of the membrane;

substantially fill the pores of the membrane; and

allowing the solvent to evaporate so that the elastomer remains in substantially all of the pores of the membrane.

28. A method of forming the composite material of the implantable article of claim 1, said method comprising the step of delivering the elastomer via a dispersion to substantially fill the pores of the at least one fluoropolymer layer.

29. A method of forming the composite material of the implantable article of claim 1, said method comprising the step of bringing the at least one fluoropolymer layer into contact with a sheet of the elastomer under conditions of heat and/or pressure that allow elastomer to substantially fill the pores of the at least one fluoropolymer layer.

30. A method of forming the composite material of the implantable article of claim 1, said method comprising the step of polymerizing the elastomer within the pores of the at least one fluoropolymer layer.

31. The implantable article as set forth in claim 10, wherein the composite material comprising less than about 50% fluoropolymer by weight.

32. An implantable article for regulating blood flow direction in a human patient, said implantable article comprising:

a support structure;

a leaflet supported on the support structure and movable between open and closed positions to regulate blood flow through the implantable article; and

a cushion member located between at least a portion of the support structure and at least a portion of the leaflet, wherein the cushion member is formed from a composite material with at least one fluoropolymer layer having a plurality of pores and an elastomer present in substantially all of the pores.

33. The implantable article as set forth in claim 32, wherein the cushion member includes expanded fluoropolymer.

34. The implantable article as set forth in claim 32, wherein the cushion member is formed as a fiber.

35. The implantable article as set forth in claim 32, wherein the cushion member is formed as a sheet.

36. The implantable article as set forth in claim 32, wherein the cushion member is formed as a tube.

37. The implantable article as set forth in claim 34, wherein the cushion member is wrapped generally helically about the at least a portion of the support structure to provide a cushion between the at least a portion of the support structure and the leaflet.

38. The implantable article as set forth in claim 32, wherein the support structure includes a longitudinally extending post about which a portion of the leaflet is wrapped to secure the leaflet to the support structure.

39. The implantable article as set forth in claim 38, wherein the cushion member is formed from porous ePTFE, wherein pores contain elastomer.

40. The implantable article as set forth in claim 39, wherein the cushion member is formed as a fiber.

41. The implantable article as set forth in claim 40, wherein the fiber is wrapped generally helically about the post to provide a cushion between the post and the portion of the leaflet wrapped about the post.

42. The implantable article as set forth in claim 40, wherein the fiber is formed from a sheet of ePTFE having a plurality of pores and an elastomer present in substantially all of the pores.

43. An implantable article for regulating blood flow direction in a human patient, said implantable article comprising:

a generally annular shaped support structure, the support structure having a first end and an opposite second end, the first end having a longitudinally extending post;

a sheet of leaflet material extending along an outer periphery of the support structure and forming a first leaflet and a second leaflet each extending along opposite sides of the post; and

a cushion member is coupled to the post and provides a cushion between the post and the leaflets.

44. The implantable article as set forth in claim 43, wherein the cushion member is a fiber formed from a sheet of ePTFE having a plurality of pores and an elastomer present in substantially all of the pores.

45. An implantable article for regulating blood flow direction in a human patient, said implantable article comprising:

a leaflet comprising a composite material having at least one fluoropolymer layer having a plurality of pores and an elastomer substantially filling the pores of the at least one fluoropolymer layer, the composite material comprising less than about 80% fluoropolymer by weight.

46. An implantable heart valve for regulating blood flow direction in a human patient, said heart valve comprising:

a leaflet cyclable between a first configuration for allowing blood flow through the heart valve and a second configuration for substantially preventing blood flow through the heart valve, the leaflet comprising a composite material having at least one fluoropolymer layer having a plurality of pores and an elastomer present in substantially all of the pores of the at least one fluoropolymer layer,

wherein the composite material has less than about 55% fluoropolymer by weight and a thickness of less than 120 μ

m.

47. The implantable heart valve as set forth in claim 46, wherein the EOA across the implantable article for regulating blood flow direction is maintained within about 10% after about 40 million cycles.

48. The implantable heart valve as set forth in claim 46, wherein a regurgitant fraction across the implantable article for regulating blood flow direction is maintained below about 15% after about 40 million cycles.

49. The implantable heart valve as set forth in claim 46, wherein the leaflet is devoid of edge delamination or hole formation after about 40 million cycles.