Functional restoration of rabbit spinal cord using collagen-filament scaffold.

We report the first success of functional restoration of transected rabbit spinal cord using collagen-filament nerve scaffold. We grafted 5 mm-long 6000 collagen filaments parallel to the axis of the spinal cord to bridge 3 mm defects of 21 adult rabbit spinal cords; 18 rabbits were used as controls. Of the 39 rabbits, 22 survived the experimental period. At 12 weeks postoperatively, regenerated axons crossed the proximal spinal cord-implant interfaces in four out of six rabbits. At 24 weeks postoperatively, regenerated axons crossed the proximal and distal spinal cord-implant interfaces in four out of six rabbits. At 24 weeks postoperatively, the Basso-Beattie-Bresnahan (BBB) locomotor rating scale scores of the rabbits in the collagen-filament grafted group were 4.7 +/- 2.3, while the score in the control group was 2.8 +/- 0.5. The BBB scale scores of the grafted group were significantly better than the control group. The results suggest that the collagen-filament nerve scaffold supports the axonal regeneration of the transected spinal cord and the restoration of function when grafted parallel to the axis of the spinal cord. The functional restoration appeared to be permanent, raising the possibility of therapeutic application in humans.