Spinal Cord Devices and Methods for Promoting Axonal Regeneration

Abstract

A spinal cord device comprises a body formed of a biocompatible, biodegradable matrix and includes a proximal cranial surface and a distal caudal surface for connection to two ends of an injured spinal cord after removal of an injured section. The body has two sets of through channels A, B, C, D, E and F with openings in the cranial surface and the caudal surface for connection of descending motor pathways from cranial white to caudal gray matter and ascending sensory pathways from caudal white to cranial gray matter of the two spinal cord ends. The device has a transversal diameter (D t ) within a range of from 9 to 13 mm, an anteroposterior diameter (D a ) and a length (L), and the ratio anteroposterior diameter/transverse diameter (RAPT) is in a range of from 0.5 to 1.0 . Kits employ a plurality of such devices.

What is claimed is: 
     
         1 . A spinal cord device for bridging an injured human spinal cord and promoting axonal regeneration, the spinal cord device comprising a body formed of a biocompatible, biodegradable matrix, the body including a proximal, cranial surface adapted for implantation on a cranial end of an injured spinal cord and a distal, caudal surface adapted for implantation on a caudal end of an injured spinal cord, for connection to a cranial end and a caudal end, respectively, of an injured spinal cord after removal of an injured spinal cord section; the body having two sets of through channels A, B, C, D, E and F with openings in the cranial surface and the caudal surface for connection of descending motor pathways from cranial white to caudal gray matter and ascending sensory pathways from caudal white to cranial gray matter of the two spinal cord ends; the spinal cord device having a transversal diameter (D i ), an anteroposterior diameter (D a ) and a length (L);
 wherein D t  is within a range of from 9 to 13 mm and the ratio anteroposterior diameter/transverse diameter (RAPT) is in a range of from 0.5 to 1.0;   wherein   (a) the two sets of channels A-F are symmetrically arranged in each of the cranial surface and the caudal surface of the device at locations corresponding with anatomical positions in the cranial end and caudal end, respectively, of the removed spinal cord section,   (b)(i) in the cranial surface:
 the channels A are positioned in opposite lateral funiculi and adjacent opposite posterior horns, 
 the channels B are positioned in opposite anterior funiculi and adjacent the ends of opposite anterior horns, 
 the channels C are positioned in gray matter at the ends of opposite posterior horns, 
 the channels D are positioned in the posterior horns, between channels C and the lateral horns, 
 the channels E are positioned in the posterior horns, between the channels D and the lateral horns, and 
 the channels F are positioned in the anterior horns, between the channels B and the lateral horns, and 
   (b)(ii) in the caudal surface:
 the channels A are positioned at the juncture of the respective anterior horn, posterior horn and the intermediate gray, 
 the channels B are positioned in gray matter at the ends of opposite anterior horns and in opposite anterior funiculi adjacent the ends of the respective anterior horns, 
 the channels C are positioned in opposite posterior funiculi and between the ends of opposite posterior horns, 
 the channels D are positioned in opposite posterior funiculi and between the opposite channels C, 
 the channels E are positioned in opposite posterior funiculi and between the openings for channels D and the intermediate gray matter, and 
 the channels F are positioned in opposite lateral funiculi and adjacent the respective anterior funiculi, and 
   (c)(i) channels A have a first diameter in a range of from 2.0-2.9 mm, and one or more of channels B, C, D, E and F have a second diameter in a range of from 1.1-1.6 mm, or (c)(ii) channels A have a first diameter in a range of from 2.0-2.9 mm, channels E have a second diameter in a range of from 1.1-1.6 mm, and channels B, C, D and F have a third diameter in a range of from 0.5-0.9 mm.   
     
     
         2 . A spinal cord device according to  claim 1 , wherein the device has been soaked in a solution comprising one or more pharmaceutically active substances. 
     
     
         3 . A spinal cord device according to  claim 1 , wherein the device has been soaked in a solution comprising FGF1. 
     
     
         4 . A spinal cord device according to  claim 1 , wherein Da is in the range of 6-10 mm. 
     
     
         5 . A spinal cord device according to  claim 1 , wherein RAPT is in the range of 0.6-0.9. 
     
     
         6 . A spinal cord device according to  claim 1 , wherein L is in the range of 15-40 mm. 
     
     
         7 . A spinal cord device kit, comprising a plurality of devices according to  claim 1 , wherein the respective D t 's of the respective devices in the kit are distributed within a range of from 9 to 13 mm and the respective ratio anteroposterior diameter/transverse diameter (RAPT)s of the respective devices in the kit are in a range of from 0.5 to 1.0. 
     
     
         8 . A spinal cord device kit according to  claim 7 , comprising at least 10 spinal cord devices, each having a cross-section with channels A, B, C, D, E and F, wherein the 10 spinal cord devices respectively have the following 10 designs, with dimensions in mm: 
       
         
           
                 
                 
                 
                 
                 
               
                     
                 
                     
                     
                     
                     
                   Channel Diameter 
                 
                 
                 
                 
                 
                 
                 
                 
               
                   Design No. 
                   D t   
                   D a   
                   RAPT 
                   A 
                   E 
                   B, C, D, F 
                 
                     
                 
                 
                 
                 
                 
                 
                 
                 
               
                   1 
                   9.25 
                   7.83 
                   0.85 
                   2.00 
                   1.10 
                   0.60 
                 
                   2 
                   10.40 
                   8.78 
                   0.84 
                   2.30 
                   1.20 
                   0.70 
                 
                   3 
                   11.56 
                   9.74 
                   0.84 
                   2.60 
                   1.40 
                   0.80 
                 
                   4 
                   9.00 
                   6.92 
                   0.77 
                   2.00 
                   1.10 
                   0.60 
                 
                   5 
                   10.20 
                   7.80 
                   0.76 
                   2.30 
                   1.20 
                   0.70 
                 
                   6 
                   11.40 
                   8.69 
                   0.76 
                   2.60 
                   1.40 
                   0.80 
                 
                   7 
                   12.60 
                   9.57 
                   0.76 
                   2.90 
                   1.60 
                   0.90 
                 
                   8 
                   9.83 
                   6.61 
                   0.67 
                   2.00 
                   1.10 
                   0.60 
                 
                   9 
                   11.18 
                   7.53 
                   0.67 
                   2.30 
                   1.20 
                   0.70 
                 
                   10 
                   12.58 
                   8.45 
                   0.67 
                   2.60 
                   1.40 
                   0.80 
                 
                     
                 
             
                
                
               
            
             
                
                
               
            
             
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         9 . A spinal cord device kit according to  claim 8 , wherein the kit includes at least two devices having the same D t , D a , RAPT and Channel Diameter dimensions and differing lengths L. 
     
     
         10 . A spinal cord device kit according to  claim 8 , comprising at least two devices for each of Designs 1-10, the respective devices for each Design having differing lengths L. 
     
     
         11 . A spinal cord device kit according to  claim 8 , comprising at least six devices for each of Designs 1-10, the respective devices for each Design having differing lengths L. 
     
     
         12 . A spinal cord device kit according to  claim 7 , wherein the kit includes at least two devices having the same D t , D a , RAPT and Channel Diameter dimensions and differing lengths L.