Biodegradable and/or bioabsorbable fibrous articles and methods for using the articles for medical applications

1. A biodegradable and/or bioabsorbable fibrous article formed by electrospinning fibers of biodegradable and/or bioabsorbable fiberizable material comprising a composite of different biodegradable and/or bioabsorbable fibers.

2. A fibrous article according to claim 1 , wherein said composite of different fibers is defined by fibers of different diameters.

3. A fibrous article according to claim 2 , wherein said fibers of different diameters include fibers having diameters less than 1 micron and fibers having diameters greater than 1 micron.

4. A fibrous article according to claim 3 , wherein said fibrous article comprises at least about 20 weight percent of submicron diameter fibers.

5. A fibrous article according to claim 4 , wherein said fibrous article comprises at least about 50 weight percent of submicron diameter fibers.

6. A fibrous article according to claim 1 , wherein said composite of different fibers is defined by fibers of different biodegradable and/or bioabsorbable materials.

7. A fibrous article according to claim 1 , wherein said composite of different fibers is defined by fibers of different diameters and different biodegradable and/or bioabsorbable materials.

8. A fibrous article according to claim 1 , wherein said biodegradable and/or bioabsorbable fiberizable material comprises a biodegradable and/or bioabsorbable polymer.

9. A fibrous article according to claim 8 , wherein said biodegradable and/or bioabsorbable polymer comprises a monomer selected from the group consisting of a glycolide, lactide, dioxanone, caprolactone, trimethylene carbonate, ethylene glycol and lysine.

10. A fibrous article according to claim 8 , wherein said biodegradable and/or bioabsorbable polymer comprises a biodegradable and/or bioabsorbable linear aliphatic polyester.

11. A fibrous article according to claim 10 , wherein said biodegradable and/or bloabsorbable linear aliphatic polyester is a polyglycolide or a copolymer poly(glycolide-co-lactide).

12. A fibrous article according to claim 1 , wherein said biodegradable and/or bioabsorbable fiberizable material comprises a material derived from biological tissue.

13. A fibrous article according to claim 1 , wherein said fibers have diameters in the range from about 10 up to about 1,000 nanometers.

14. A fibrous article according to claim 13 , wherein said fibers have diameters in the range from about 20 to about 500 nanometers.

15. A fibrous article according to claim 1 , further comprising small blobs of biodegradable and/or bioabsorbable material.

16. A fibrous article according to claim 1 , further comprising at least one medicinal agent.

17. A fibrous article according to claim 16 , wherein said medicinal agent is contained within said fibers.

18. A fibrous article according to claim 17 , further comprising fibers with different concentrations of said medicinal agent.

19. A fibrous article according to claim 17 , further comprising fibers with different medicinal agents.

20. A fibrous article according to claim 1 , further comprising a plurality of layers, wherein at least one of the layers comprises a composite of different biodegradable and/or bioabsorbable fibers.

21. A fibrous article according to claim 20 , further comprising at least one medicinal agent between at least two of said layers.

22. A fibrous article according to claim 1 , wherein said fibrous article has a controlled degradation rate.

23. A fibrous article according to claim 1 , wherein said fibrous article is a membrane.

24. A fibrous article according to claim 23 , wherein said membrane has a thickness in the range of about 10 to about 5000 microns.

25. A fibrous article according to claim 24 , wherein said membrane has a thickness in the range of about 20 to about 1000 microns.

26. A fibrous article according to claim 1 , wherein said composite is an asymmetric composite of different biodegradable and/or bioabsorbable fibers.

27. A fibrous article according to claim 26 , wherein different fibers refers to fibers of different diameters.

28. A fibrous article according to claim 27 , wherein said fibers of different diameters include fibers having diameters less than 1 micron and fibers having diameters greater than 1 micron.

29. A fibrous article according to claim 28 , wherein said fibrous article comprises at least about 20 weight percent of submicron diameter fibers.

30. A fibrous article according to claim 29 , wherein said fibrous article comprises at least about 50 weight percent of submicron diameter fibers.

31. A fibrous article according to claim 26 , wherein different fibers refers to fibers of different biodegradable and/or bioabsorbable materials.

32. A fibrous article according to claim 26 , wherein different fibers refers to fibers of different diameters and different biodegradable and/or bioabsorbable materials.

33. A fibrous article according to claim 26 , wherein said biodegradable and/or bioabsorbable fiberizable material comprises a biodegradable and/or bioabsorbable polymer.

34. A fibrous article according to claim 33 , wherein said biodegradable and/or bioabsorbable polymer comprises a monomer selected from the group consisting of a glycolide, lactide, dioxanone, caprolactone, trimethylene carbonate, ethylene glycol and lysine.

35. A fibrous article according to claim 33 , wherein said biodegradable and/or bioabsorbable polymer comprises a biodegradable and/or bioabsorbable linear aliphatic polyester.

36. A fibrous article according to claim 35 , wherein said biodegradable and/or bioabsorbable linear aliphatic polyester is a polyglycolide or a copolymer poly(glycolide-co-lactide).

37. A fibrous article according to claim 26 , wherein said biodegradable and/or bioabsorbable fiberizable material comprises a material derived from biological tissue.

38. A fibrous article membrane according to claim 26 , wherein said fibers have diameters in the range from about 10 up to about 1,000 nanometers.

39. A fibrous article according to claim 38 , wherein said fibers have diameters in the range from about 20 to about 500 nanometers.

40. A fibrous article according to claim 26 , further comprising small blobs of biodegradable and/or bioabsorbable material.

41. A fibrous article according to claim 26 , further comprising at least one medicinal agent.

42. A fibrous article according to claim 41 , wherein said medicinal agent is contained within said fibers.

43. A fibrous article according to claim 42 , further comprising fibers with different concentrations of said medicinal agent.

44. A fibrous article according to claim 42 , further comprising fibers with different medicinal agents.

45. A fibrous article according to claim 26 , wherein said fibrous article has a controlled degradation rate.

46. A fibrous article according to claim 26 , wherein said fibrous article is a membrane.

47. A fibrous article according to claim 46 , wherein said membrane has a thickness in the range of about 10 to about 5000 microns.

48. A fibrous article according to claim 47 , wherein said membrane has a thickness in the range of about 20 to about 1000 microns.

49. A fibrous article formed by electrospinning different fibers of different materials, comprising a composite of different fibers which comprises fibers of at least one biodegradable material and fibers of at least one non-biodegradable material.

50. A fibrous article according to claim 49 , wherein said different fibers comprise submicron diameter fibers.

51. A fibrous article according to claim 49 , wherein said composite is an asymmetric composite of said different fibers.

52. A method for reducing surgical adhesions which comprises positioning an adhesion-reducing barrier between the site of surgical activity and neighboring tissue, said barrier comprising a biodegradable and/or bioabsorbable membrane, wherein said membrane comprises a composite or asymmetric composite of different biodegradable and/or bioabsorbable fibers; a plurality of layers, with at least two layers having different biodegradable and/or bioabsorbable fibers from each other; or sub-micron diameter biodegradable and/or bioabsorbable fibers, having at least one medicinal agent contained within the fibers.

53. A method according to claim 52 , wherein different fibers refers to fibers of different diameters.

54. A method according to claim 52 , wherein different fibers refers to fibers of different biodegradable and/or bioabsorbable materials.

55. A method according to claim 52 , wherein different fibers refers to fibers of different diameters and different biodegradable and/or bioabsorbable materials.

56. A method for providing controlled tissue healing which comprises implanting at a target site in an animal, a system for controlled tissue healing, said system comprising a biodegradable and/or bioabsorbable fibrous article, wherein said fibrous article comprises a composite of different biodegradable and/or bioabsorbable fibers or an asymmetric composite of different biodegradable and/or bioabsorbable fibers.

57. A method according to claim 56 , wherein said fibrous article is selected from the group consisting of a scaffold for guided tissue regeneration, a protective covering for redirecting healing, a protective covering for weakened tissue and an anti-fibroblastic growth barrier.

58. A method according to claim 56 , wherein different fibers refers to fibers of different diameters.

59. A method according to claim 56 , wherein different fibers refers to fibers of different biodegradable and/or bioabsorbable materials.

60. A method according to claim 56 , wherein different fibers refers to fibers of different diameters and different biodegradable and/or bioabsorbable materials.