Proteoglycan-reduced soft tissue xenografts

• US 20010039459A1
• Filed: 06/04/2001
• Published: 11/08/2001
• Est. Priority Date: 02/11/1999
• Status: Active Grant

• Current Assignee: Aperion Biologics, Inc.
• Original Assignee: CROSSMARK Incorporated
• Inventors: Stone, Kevin R.
• Granted Patent: US 6,455,309 B2
• Time in Patent Office: Days
• US Class Current: 623/23.72
• CPC Class Codes: A61L 2430/34 for soft tissue reconstruction
• CPC Class Codes: A61L 2430/40 Preparation and treatment of biological tissue for implantation, e.g. decellularisation, cross-linking
• CPC Class Codes: A61L 27/3604 characterised by the human or animal origin of the biological material, e.g. hair, fascia, fish scales, silk, shellac, pericardium, pleura, renal tissue, amniotic membrane, parenchymal tissue, fetal tissue, muscle tissue, fat tissue, enamel
• CPC Class Codes: A61L 27/3687 characterised by the use of chemical agents in the treatment, e.g. specific enzymes, detergents, capping agents, crosslinkers, anticalcification agents
• CPC Class Codes: A61L 27/3691 characterised by physical conditions of the treatment, e.g. applying a compressive force to the composition, pressure cycles, ultrasonic/sonication or microwave treatment, lyophilisation
• CPC Class Codes: Y10S 623/915 Method or apparatus for preparing biological material

Abstract

The invention provides an article of manufacture comprising a substantially non-immunogenic soft tissue xenograft for implantation into humans. The invention further provides methods for preparing a soft tissue xenograft by removing at least a portion of a soft tissue from a non-human animal to provide a xenograft; washing the xenograft in saline and alcohol; subjecting the xenograft to cellular disruption treatment; and digesting the xenograft with a proteoglycan-depleting factor and/or glycosidase and optionally following with a capping treatment. The invention also provides an article of manufacture produced by the above-identified method of the invention. The invention further provides a soft tissue xenograft for implantation into a human including a portion of a soft tissue from a non-human animal, wherein the portion has extracellular components and substantially only dead cells. The extracellular components have reduced proteoglycan molecules. Each of the xenografts of the invention are substantially non-immunogenic and have substantially the same mechanical properties as a corresponding native soft tissue.

Claims

1. A method of preparing a soft tissue xenograft for implantation into a human, which comprises:

a. removing at least a portion of a soft tissue from a non-human animal to provide a xenograft;

b. washing the xenograft in water and alcohol;

c. subjecting the xenograft to a cellular disruption treatment; and

d. depleting substantially a plurality of proteoglycans from the xenograft,

whereby the xenograft is substantially non-immunogenic and has substantially the same mechanical properties as the native soft tissue.

2. A method according to

claim 1

, wherein the depleting step comprises digesting the xenograft with at least one proteoglycan-depleting factor selected from the group consisting of chondroitinase ABC, hyaluronidase, chondroitin AC II lyase, keratanase, trypsin and fibronectin fragment.

3. A method according to

claim 1

further comprising the step of

after step c, piercing the xenograft.

4. A method according to

claim 1

further comprising the step of

after step c, treating the xenograft with at least one enzyme.

5. A method according to

claim 4

, wherein the enzyme is selected from the group consisting of ficin and trypsin.

6. A method according to

claim 1

further comprising the step of

after step c, treating the xenograft with one or more agents selected from the group consisting of anticalcification agents, antithrombotic agents, antibiotics, and growth factors.

7. A method according to

claim 1

further comprising the step of

after step c, sterilizing the xenograft.

8. A method according to

claim 7

, wherein the sterilizing step comprises sterilizing the xenograft with one or more agents selected from the group consisting of ethylene oxide and propylene oxide.

9. A method according to

claim 1

further comprising the step of:

after step c, treating the xenograft with polyethylene glycol.

10. A method according to

claim 1

further comprising the step of

after step c, exposing the xenograft to a crosslinking agent in a vapor form.

11. A method according to

claim 1

, wherein the cellular disruption treatment comprises freeze/thaw cycling.

12. A method according to

claim 1

, wherein the cellular disruption treatment comprises exposure to gamma radiation.

13. A method according to

claim 1

further comprising the step of

after step d, removing substantially a plurality of first surface carbohydrate moieties from the xenograft.

14. A method according to

claim 1

, wherein the removing step comprises digesting the xenograft with a glycosidase.

15. A method according to

claim 14

, wherein the glycosidase is a galactosidase.

16. A method according to

claim 15

, wherein the galactosidase is an α

-galactosidase.

17. A method according to

claim 13

further comprising the step of

following the removing step, treating a plurality of second surface carbohydrate moieties on the xenograft with a plurality of capping molecules to cap at least a portion of the second surface carbohydrate moieties.

18. A method according to

claim 16

, wherein at least a portion of the capping molecules are a plurality of fucosyl molecules.

19. A method according to

claim 16

, wherein at least a portion of the capping molecules are a plurality of n-acetyl glucosamine molecules.

20. A method according to

claim 1

, wherein the removing step comprises removing the portion of a medial or lateral meniscus having a superior principal surface and an inferior principal surface, each of the principal surfaces having an outer portion being joined by an outer lateral surface, and each of the principal surfaces having an inner portion being joined by an inner lateral surface.

21. A method according to

claim 1

, wherein the removing step comprises removing the portion of a ligament.

22. A method according to

claim 21

, wherein the removing step comprises removing with the portion of the ligament a first block of bone attached to a first end of the portion.

23. A method according to

claim 22

, wherein the removing step comprises removing with the portion of the ligament a second block of bone affixed to a second end of the portion opposite the first end.

24. A method according to

claim 1

, wherein the removing step comprises removing the portion of an articular cartilage.

25. A method according to

claim 24

, wherein the removing step comprises removing with the portion of the articular cartilage a layer of subchondral bone.

26. An article of manufacture comprising a substantially non-immunogenic, proteoglycan-reduced soft tissue xenograft for implantation into a human, produced by:

a. removing at least a portion of a soft tissue from a non-human animal to provide a xenograft;

b. washing the xenograft in water and alcohol;

c. subjecting the xenograft to a cellular disruption treatment; and

d. digesting the xenograft with a proteoglycan-depleting factor to remove substantially a plurality of proteoglycans from the xenograft,

whereby the xenograft is substantially non-immunogenic and has substantially the same mechanical properties as the native soft tissue.

27. An article of manufacture according to

claim 26

, wherein the proteoglycan-depleting factor is selected from the group consisting of chondroitinase ABC, hyaluronidase, chondroitin AC II lyase, keratanase, trypsin and fibronectin fragment.

28. An article of manufacture according to

claim 26

, wherein the xenograft has a plurality of punctures for increasing permeability to agents and enzymes.

29. An article of manufacture according to

claim 26

further comprising one or more agents selected from the group consisting of anticalcification agents, antithrombotic agents, antibiotics, and growth factors.

30. An article of manufacture according to

claim 26

, wherein the xenograft is sterilized.

31. An article of manufacture according to

claim 26

, wherein the xenograft is a polyethylene glycol-treated xenograft.

32. An article of manufacture according to

claim 26

further comprising a crosslinking agent.

33. An article of manufacture according to

claim 26

, wherein the xenograft has a plurality of first surface carbohydrate moieties substantially removed.

34. An article of manufacture according to

claim 33

, wherein the xenograft is a glycosidase-treated xenograft.

35. An article of manufacture according to

claim 34

, wherein the glycosidase-treated xenograft is a galactosidase-treated xenograft.

36. An article of manufacture according to

claim 35

, wherein the galactosidase-treated xenograft is an α

-galactosidase-treated xenograft.

37. An article of manufacture according to

claim 33

further comprising a plurality of capping molecules capped on a plurality of second surface carbohydrate moieties on the xenograft.

38. An article of manufacture according to

claim 37

, wherein the capping molecules are selected from one or more of the groups of fucosyl molecules and n-acetyl glucosamine molecules.

39. An article of manufacture according to

claim 26

, wherein the xenograft is a thawed, frozen xenograft.

40. An article of manufacture according to

claim 26

, wherein the xenograft is a gamma-irradiated xenograft.

41. An article of manufacture according to

claim 26

, wherein the portion is of a medial or lateral meniscus having a superior principal surface and an inferior principal surface, each of the principal surfaces having an outer portion being joined by an outer lateral surface, and each of the principal surfaces having an inner portion being joined by an inner lateral surface.

42. An article of manufacture according to

claim 26

, wherein the portion is of a ligament.

43. An article of manufacture according to

claim 42

, wherein the portion of the ligament comprises a first block of bone attached to a first end of the portion.

44. An article of manufacture according to

claim 43

, wherein the portion of the ligament comprises a second block of bone affixed to a second end of the portion opposite the first end.

45. An article of manufacture according to

claim 26

, wherein the portion is of an articular cartilage.

46. An article of manufacture according to

claim 45

, wherein the portion of the articular cartilage comprises a layer of subchondral bone.

47. A soft tissue xenograft for implantation into a human comprising

a portion of a soft tissue from a non-human animal, wherein the portion includes a plurality of substantially only dead cells and a plurality of extracellular components, the extracellular components having reduced proteoglycans, whereby the portion of the soft tissue is substantially non-immunogenic and has substantially the same mechanical properties as the native soft tissue.

48. A soft tissue xenograft according to

claim 47

, wherein the extracellular components and the substantially only dead cells have substantially no surface α

-galactosyl moieties.

49. A soft tissue xenograft according to

claim 47

, wherein the portion has capping molecules linked to at least a portion of a plurality of surface carbohydrate moieties on the xenograft.

50. A soft tissue xenograft according to

claim 49

, wherein at least a portion of the capping molecules are a plurality of fucosyl molecules.

51. A soft tissue xenograft according to

claim 49

, wherein at least a portion of the capping molecules are a plurality of n-acetyl glucosamine molecules.

52. A soft tissue xenograft according to

claim 47

, wherein the portion is of a medial or lateral meniscus having a superior principal surface and an inferior principal surface, each of the principal surfaces having an outer portion being joined by an outer lateral surface, and each of the principal surfaces having an inner portion being joined by an inner lateral surface.

53. A soft tissue xenograft according to

claim 47

, wherein the portion is of a ligament.

54. A soft tissue xenograft according to

claim 52

, wherein the portion of the ligament comprises a first block of bone attached to a first end of the portion.

55. A soft tissue xenograft according to

claim 53

, wherein the portion of the ligament comprises a second block of bone affixed to a second end of the portion opposite the first end.

56. A soft tissue xenograft according to

claim 47

, wherein the portion is of an articular cartilage.

57. A soft tissue xenograft according to

claim 55

, wherein the portion of the articular cartilage comprises a layer of subchondral bone.