Enhancement of nerve regeneration along a chitosan nanofiber mesh tube on which electrically polarized β-tricalcium phosphate particles are immobilized

The ability of β-tricalcium phosphate (β-TCP) particles to store electric charge was confirmed by thermally stimulated depolarization current measurement as well as surface potential measurement. The efficacy of stored electrical charge on β-TCP particles in enhancing nerve regeneration was evaluated. Bridge grafting was performed into sciatic nerve defects in Wistar rats with the following tubes: chitosan mesh tubes; chitosan mesh tubes on which β-TCP particles with or without electrical polarization treatment had been immobilized (polarized and non-polarized tubes, respectively). As a control, isografts were used. Both motor and sensory nerve function as well as electrophysiological recovery progressed with time in each group. Immunofluorescence revealed rapider nerve regeneration in the polarized tube group compared with the non-polarized tube group. The axon density and axon area in the polarized tube group were significantly greater than those in the chitosan mesh tube and non-polarized group, and showed no significant differences from the control group. These results suggest that the stored charge on electrically polarized β-TCP particles immobilized on chitosan mesh tubes may enhance nerve regeneration to the same extent as isografting.