Effectiveness of magnetically aligned collagen for neural regeneration in vitro and in vivo.

We investigated the effectiveness of using magnetically aligned collagen (after exposure to a maximum 8-T magnetic field) for nerve regeneration in both an in vitro and in vivo model. Neurite outgrowth from embryonic chick dorsal root ganglion (DRG) neurons was significantly greater on magnetically aligned collagen gel than on control gel, and was dependent on magnetic field strength. Silicone tubes (15 mm length) filled with collagen gel formed bridges between severed rat sciatic nerves. We prepared tubes for four groups: collagen gel only (COL), magnetically aligned collagen gel (M-COL), collagen gel mixed with Schwann cells (S-COL), and magnetically aligned collagen gel mixed with Schwann cells (M-S-COL). The ratio of infiltrating regenerated nerves was higher in the M-COL group compared to the COL group at 8 weeks post-operation. There were no significant differences between the two groups with and without Schwann cells. Compound action potentials showed higher amplitude and shorter latency in the M-COL than COL group at 12 weeks post-operation. The number and diameter of regenerated axons increased significantly in the M-COL compared with the COL group at 12 weeks post-operation. Here we demonstrated that magnetically orientated collagen promoted nerve regeneration using both an in vitro and in vivo model.