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

• US 20120323315A1
• Filed: 05/31/2012
• Published: 12/20/2012
• Est. Priority Date: 04/01/2011
• Status: Active Grant

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Bruchman, William C., Hartman, Cody L.
• Granted Patent: US 8,945,212 B2
• Time in Patent Office: Days
• US Class Current: 623/2.17
• CPC Class Codes: A61F 2/2403 with pivoting rigid closure members check valves with hinged closure members in general F16K15/03
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• 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 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2240/005 Templates
• CPC Class Codes: A61L 2420/04 Coatings containing a composite material such as inorganic/organic, i.e. material comprising different phases
• CPC Class Codes: A61L 2420/08 Coatings comprising two or more layers
• CPC Class Codes: A61L 2430/20 for reconstruction of the heart, e.g. heart valves
• CPC Class Codes: A61L 27/34 Macromolecular materials
• 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: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: Y10T 29/49412 with assembly, disassembly or composite article making

Abstract

A thin, biocompatible, high-strength, composite material is disclosed that is suitable for use in various implanted configurations. 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 at least one porous expanded fluoropolymer layer and an elastomer substantially filling substantially all of the pores of the porous expanded fluoropolymer.

Claims

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

a leaflet having a thickness and formed from a composite material having more than one fluoropolymer layer having a plurality of pores and an elastomer present in substantially all of the pores of the more than one fluoropolymer layer, the leaflet having a ratio of leaflet thickness (μ

m) to number of layers of fluoropolymer of less than about 5.

2. The implantable article as set forth in claim 1, wherein the ratio of leaflet thickness (μ

m) to number of layers of fluoropolymer of less than about 3.

3. The implantable article as set forth in claim 1, wherein the ratio of leaflet thickness (μ

m) to number of layers of fluoropolymer of less than about 1.

4. The implantable article as set forth in claim 1, wherein the ratio of leaflet thickness (μ

m) to number of layers of fluoropolymer of less than about 0.5.

5. The implantable article as set forth in claim 1, wherein the EOA across the implantable article for regulating blood flow direction is maintained within 10% of the pre-cycling value after 40 million cycles.

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

7. The implantable article as set forth in claim 1, wherein the leaflet has at least 10 layers and a composite material comprising less than about 50% fluoropolymer by weight.

8. The implantable article as set forth in claim 7, wherein the leaflet has a thickness less than 100 μ

m.

9. The implantable article as set forth in claim 8, wherein the leaflet has a bending modulus of less than about 100 MPa.

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

a leaflet cyclable between a closed configuration for substantially preventing blood flow through the implantable article and an open configuration allowing blood flow through the implantable article, the leaflet being formed from a plurality of fluoropolymer layers and having a ratio of leaflet thickness (μ

m) to number of layers of fluoropolymer of less than about 5, the leaflet maintaining substantially unchanged performance after actuation of the leaflet to at least 40 million cycles.

11. The implantable article as set forth in claim 10, wherein the leaflet remains substantially impermeable after actuation of the leaflet to at least 40 million cycles.

12. The implantable article as set forth in claim 11, wherein the leaflet remains substantially impermeable after actuation of the leaflet to at least 40 million cycles in vivo.

13. The implantable article as set forth in claim 10, wherein the leaflet is operatively coupled to a support frame and movable between the closed and open configurations relative to the support frame.

14. The implantable article as set forth in claim 13, wherein the support frame is selectively diametrically adjustable for endovascular delivery and deployment at a treatment site.

15. The implantable article as set forth in claim 10, wherein the performance of the leaflet remains substantially unchanged after compacting and expanding prior to cycling of the leaflet.

16. The implantable article as set forth in claim 10, wherein the performance of the leaflet remains substantially unchanged after endovascular delivery of the implantable article.

17. The implantable article as set forth in claim 10, wherein the leaflet encompasses a radiopaque element.

18. A method of forming a leaflet of an implantable article for regulating blood flow direction in a human patient, the method comprising:

providing a composite material having more than one fluoropolymer layer having a plurality of pores and an elastomer present in substantially all of the pores of the more than one fluoropolymer layer; and

bringing more than one layer of the composite material into contact with additional layers of the composite material by wrapping a sheet of the composite material with a starting and ending point defined as an axial seam adhered to itself.

19. The method as set forth in claim 18, wherein the sheet of the composite material is wrapped generally radially with the starting and ending point defined as the axial seam adhered to itself.

20. The method as set forth in claim 19, wherein the sheet of the composite material is substantially contiguous.

21. The method as set forth in claim 18, wherein the sheet of the composite material has a ratio of leaflet thickness (μ

m) to number of layers of fluoropolymer of less than about 5.

22. An implantable article for regulating blood flow direction in a human patient, the article comprising a polymeric leaflet having a thickness of less than about 100 μ

m.

23. The implantable article as set forth in claim 22, wherein the leaflet is formed from a composite material having more than one fluoropolymer layer having a plurality of pores and an elastomer present in substantially all of the pores of the more than one fluoropolymer layer.

24. The implantable article as set forth in claim 23, wherein the leaflet includes at least 10 layers of the composite material.

25. An implantable article for regulating blood flow direction in a human patient, 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.

26. The implantable article as set forth in claim 25, wherein the composite material comprises less than about 70% fluoropolymer by weight.

27. The implantable article as set forth in claim 25, wherein the composite material comprises less than about 60% fluoropolymer by weight.

28. The implantable article as set forth in claim 25, wherein the composite material comprises less than about 50% fluoropolymer by weight.

29. The implantable article as set forth in claim 25, wherein the composite material further includes a layer of the elastomer.

30. The implantable article as set forth in claim 29, wherein the elastomer is a fluoroelastomer.

31. The implantable article as set forth in claim 30, wherein the elastomer is a TFE/PMVE copolymer.

32. The implantable article as set forth in claim 31, wherein the copolymer comprises essentially of between about 40 and 80 weight percent perfluoromethyl vinyl ether and complementally 60 and 20 weight percent tetrafluoroethylene.

33. The implantable article as set forth in claim 29, wherein the fluoropolymer is PTFE.

34. The implantable article as set forth in claim 29, wherein the PTFE is ePTFE.

35. The implantable article as set forth in claim 34, wherein the at least one fluoropolymer layer has a matrix tensile strength in at least one direction greater than about 96 MPa.

36. The implantable article as set forth in claim 25, wherein the elastomer is a fluoroelastomer.

37. The implantable article as set forth in claim 36, wherein the elastomer is a TFE/PMVE copolymer.

38. The implantable article as set forth in claim 37, wherein the copolymer comprises essentially of between about 40 and 80 weight percent perfluoromethyl vinyl ether and complementally about 60 and 20 weight percent tetrafluoroethylene.

39. The implantable article as set forth in claim 25, wherein the fluoropolymer is PTFE.

40. The implantable article as set forth in claim 38, wherein the PTFE is ePTFE.

41. The implantable article as set forth in claim 39, wherein the at least one fluoropolymer layer has a matrix tensile strength in at least one direction greater than about 96 MPa.

42. The implantable article as set forth in claim 25, wherein the leaflet has a thickness of less than about 350 μ

m.

43. The implantable article as set forth in claim 25, wherein the leaflet has a thickness of less than about 300 μ

m

44. The implantable article as set forth in claim 25, wherein the leaflet has a thickness of less than about 200 μ

m.

45. The implantable article as set forth in claim 25, wherein the leaflet has a thickness of less than about 100 μ

m.

46. The implantable article as set forth in claim 25, wherein the leaflet has a thickness of less than about 50 μ

m.

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

m.

48. The implantable article as set forth in claim 25, wherein the EOA across the implantable article for regulating blood flow direction is maintained within about 10% after about 40 million cycles.

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

50. The leaflet as set forth in claim 25, wherein the leaflet is devoid of edge delamination or hole formation after about 40 million cycles.

51. A method of forming the composite material of the implantable article of claim 25, the 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.

52. A method of forming the composite material of the implantable article of claim 25, the method comprising the step of delivering the elastomer via a dispersion to substantially fill the pores of the at least one fluoropolymer layer.

53. A method of forming the composite material of the implantable article of claim 25, the method comprising the step of bringing the at least one fluoropolymer layer into contact with a sheet of the elastomer under conditions of heat or pressure that allow elastomer to substantially fill the pores of the at least one fluoropolymer layer.

54. A method of forming the composite material of the implantable article of claim 25, the method comprising the step of polymerizing the elastomer within the pores of the at least one fluoropolymer layer.

55. The implantable article as set forth in claim 34, wherein the composite material comprises less than about 50% fluoropolymer by weight.

56. An implantable article for regulating blood flow direction in a human patient, the 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.

57. The implantable article as set forth in claim 56, wherein the cushion member includes expanded fluoropolymer.

58. The implantable article as set forth in claim 56, wherein the cushion member is formed as a fiber.

59. The implantable article as set forth in claim 56, wherein the cushion member is formed as a sheet.

60. The implantable article as set forth in claim 56, wherein the cushion member is formed as a tube.

61. The implantable article as set forth in claim 58, 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.

62. The implantable article as set forth in claim 56, 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.

63. The implantable article as set forth in claim 58, wherein the fluoropolymer layer of the cushion member is formed from porous ePTFE.

64. The implantable article as set forth in claim 63, wherein the cushion member is formed as a fiber.

65. The implantable article as set forth in claim 64, 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.

66. The implantable article as set forth in claim 64, 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.

67. An implantable article for regulating blood flow direction in a human patient, the 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 coupled to the post to provide a cushion between the post and the leaflets.

68. The implantable article as set forth in claim 67, 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.

69. An implantable article for regulating blood flow direction in a human patient, the 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.