Spinal cord surgical implant

• US 7,163,545 B2
• Filed: 07/29/2003
• Issued: 01/16/2007
• Est. Priority Date: 07/29/2002
• Status: Active Grant

• Current Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic)
• Original Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic)
• Inventors: Yaszemski, Michael J., Moore, Michael J., Windebank, Anthony J., Friedman, Jonathan A.
• Primary Examiner(s): Hayes; Michael J.
• Assistant Examiner(s): Mendoza; Michael G.
• Application Number:
  US10/629,427
• Publication Number:
  US 20040102793A1
• Time in Patent Office: 1,267 Days
• Field of Search: 606/76, 606/77, 606/152, 606/153, 606/154, 606/155, 424/423, 424/424, 424/426
• US Class Current: 606/152
• CPC Class Codes: A61B 17/08 Wound clamps or clips, i.e. not or only partly penetrating the tissue suture bridges A61B17/0466; Devices for bringing together the edges of a wound
• CPC Class Codes: A61B 17/1128 of nerves
• CPC Class Codes: A61L 2430/32 for nerve reconstruction
• CPC Class Codes: A61L 27/383 Nerve cells, e.g. dendritic cells, Schwann cells
• CPC Class Codes: A61L 27/3878 Nerve tissue, brain, spinal cord, nerves, dura mater
• CPC Class Codes: A61L 27/58 Materials at least partially resorbable by the body
• CPC Class Codes: A61L 31/005 Ingredients of undetermined constitution or reaction products thereof
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body

Abstract

An implant for bridging a gap in a severed spinal cord or nerve and for promoting nerve regeneration has a matrix comprising a biocompatible, biodegradable, polymeric material. The matrix has a proximal end for connection to a first end of severed spinal cord and a distal end for connection to a second end of severed spinal cord. The matrix includes internal guidance channels extending between the proximal end and the distal end to facilitate rejoining of the first end and the second end of the severed spinal cord. A bioactive agent may be dispersed in the matrix, or disposed in the channels, or included within microspheres in the channels. The channels may be arranged such that guidance channels correspond to spinal cord tracts. Alternatively, guidance channels may be spaced apart at the proximal end of the matrix and converge inward toward the axis of the matrix at the distal end.

Claims

1. An implant for bridging a gap in a severed spinal cord or nerve and for promoting nerve regeneration, the implant comprising:

a matrix comprising a biocompatible, biodegradable, polymeric material and a bioactive agent dispersed within the matrix, the matrix having a proximal end for connection to a first end of a severed spinal cord or nerve and a distal end for connection to a second end of the severed spinal cord or nerve,

wherein the matrix includes a plurality of internal guidance channels extending between the proximal end of the matrix and the distal end of the matrix to facilitate rejoining of the first end of the severed spinal cord or nerve and the second end of the severed spinal cord or nerve, and

wherein the bioactive agent is a proteoglycan degrading enzyme, and

the guidance channels are spaced apart adjacent a perimeter of the matrix at the proximaI end of the matrix and converge inward toward the axis of the matrix at the distal end of the matrix.

2. The implant of claim 1 wherein:

the polymeric material is poly(lactide-co-glycolide).

3. The implant of claim 1 further comprising:

Schwann cells disposed within at least one of the plurality of guidance channels.

4. The implant of claim 1 wherein:

the proteoglycan degrading enzyme is chondroitinase.

5. The implant of claim 4 wherein:

the chondroitinase is chondroitinase ABC.

6. The implant of claim 1 wherein:

biocompatible, biodegradable, polymeric microspheres including a second bioactive agent are disposed within at least one of the plurality of guidance channels.

7. The implant of claim 6 wherein:

the microspheres comprise poly(lactide-co-glycolide).

8. The implant of claim 6 wherein:

the second bioactive agent is a proteoglycan degrading enzyme.

9. The implant of claim 8 wherein:

the proteoglycan degrading enzyme is chondroitinase.

10. The implant of claim 9 wherein:

the chondroitinase is chondroitinase ABC.

11. The implant of claim 1 wherein:

the guidance channels are arranged such that the guidance channels correspond to spinal cord tracts when the implant is positioned in a gap in a severed spinal card.

12. The implant of claim 1 wherein:

Schwann cells disposed within at least one of the plurality of guidance channels, and

biocompatible, biodegradable, polymeric microspheres including a second bioactive agent other than Schwann cells are disposed within at least one of the plurality of guidance channels.

13. The implant of claim 1 wherein:

Schwann cells disposed within at least one of the plurality of guidance channels, and

a second bioactive agent other than Schwann cells is disposed within at least one of the plurality of guidance channels.

14. An implant for bridging a gap in a severed spinal cord or nerve and for promoting nerve regeneration, the implant comprising:

a matrix comprising a biocompatible, biodegradable, polymeric material, the matrix having a proximal end for connection to a first end of a severed spinal cord or nerve and a distal end for connection to a second end of the severed spinal cord or nerve,

wherein the matrix includes a plurality of internal guidance channels extending between the proximal end of the matrix and the distal end of the matrix to facilitate rejoining of the first end of the severed spinal cord or nerve and the second end of the severed spinal cord or nerve, and

wherein a bioactive agent other than Schwann cells is disposed in at least one of the guidance channels, and

wherein the bioactive agent is a proteoglycan degrading enzyme, and

the guidance channels are spaced apart adjacent a perimeter of the matrix at the proximal end of the matrix and converge inward toward the axis of the matrix at the distal end of the matrix.

15. The implant of claim 14 wherein:

the proteoglycan degrading enzyme is chondroitinase.

16. The implant of claim 15 wherein:

the chondroitinase is chondroitinase ABC.

17. The implant of claim 14 wherein:

the bioactive agent in included within biocompatible, biodegradable, polymeric microspheres disposed within at least one of the plurality of guidance channels.

18. The implant of claim 17 wherein:

the microspheres comprise poly(lactide-co--glycolide).

19. The implant of claim 17 wherein:

the microspheres are suspended in a carrier.

20. The implant of claim 17 wherein:

the proteoglycan degrading enzyme is chondroitinase.

21. The implant of claim 20 wherein:

the chondroitinase is chondroitinase ABC.

22. The implant of claim 14 wherein:

the guidance channels are arranged such that the guidance channels correspond to spinal cord tracts when the implant is positioned in a gap in a severed spinal cord.

23. An implant for bridging a gap in a severed spinal cord or nerve and for promoting nerve regeneration, the implant comprising:

a matrix comprising a biocompatible, biodegradable, polymeric material, the matrix having a proximal end for connection to a first end of a severed spinal cord or nerve and a distal end for connection to a second end of the severed spinal cord or nerve,

wherein the matrix includes a plurality of internal guidance channels extending between the proximal end of the matrix and the distal end of the matrix to facilitate rejoining of the first end of the severed spinal cord or nerve and the second end of the severed spinal cord or nerve, and

wherein the guidance channels are spaced apart adjacent a perimeter of the matrix at the proximal end of the matrix and converge inward toward the axis of the matrix at the distal end of the matrix.

24. The implant of claim 23 wherein:

Schwann cells disposed within at least one of the plurality of guidance channels, and

biocompatible, biodegradable, polymeric microspheres including a bioactive agent other than Schwann cells are disposed within at least one of the plurality of guidance channels.

25. The implant of claim 24 wherein:

the bioactive agent is a proteoglycan degrading enzyme.

26. The implant of claim 23 wherein:

Schwann cells disposed within at least one of the plurality of guidance channels, and

a bioactive agent other than Schwann cells is disposed within at least one of the plurality of guidance channels.

27. The implant of claim 26 wherein:

the bioaotive agent is a proteoglycan degrading enzyme.