The effect of intraluminal contact mediated guidance signals on axonal mismatch during peripheral nerve repair.

The current microsurgical gold standard for repairing long gap nerve injuries is the autograft. Autograft provides a protective environment for repair and a natural internal architecture, which is essential for regeneration. Current clinically approved hollow nerve guidance conduits allow provision of this protective environment; however they fail to provide an essential internal architecture to the regenerating nerve. In the present study both structured and unstructured intraluminal collagen fibres are investigated to assess their ability to enhance conduit mediated nerve repair. This study presents a direct comparison of both structured and unstructured fibres in vivo. The addition of intraluminal guidance structures was shown to significantly decrease axonal dispersion within the conduit and reduced axonal mismatch of distal nerve targets (p < 0.05). The intraluminal fibres were shown to be successfully incorporated into the host regenerative process, acting as a platform for Schwann cell migration and axonal regeneration. Ultimately the fibres were able to provide a platform for nerve regeneration in a long term regeneration study (16 weeks) and facilitated increased guidance of regenerating axons towards their distal nerve targets.