How to Direct the Neuronal Growth Process in Peripheral Nerve Regeneration: Future Strategies for Nanosurfaces Scaffold and Magnetic Nanoparticles.

Currently, the gold standard to repair large nerve defects is the autologous nerve graft. These solutions offer a mechanical support, adhesion substrates, and, with Schwann cells (SC), a source of neurotropic factors for axonal growth. The technical limits are the donor side damage, multiple surgical accesses, and the unavailability of large amounts of grafts. In recent years, several researchers focused their attention on the interaction between cells (nervous and glial) and physic-chemical cues that arise from the extracellular milieu. Nanotechnologies produce surfaces that mimic the topographical signals (physical stimuli) that arise from enterprise content management (ECM) to modulate the forces acting during axonal elongation. The use of magnetic nanoparticles (MNPs) seems to be able to guide and to boost the nerve regeneration. Both research areas could be improved through surfaces functionalization by biological molecules (proteins/peptides, growth factors, etc.). In the future, the aim will be to help recovery after peripheral nerve lesion by producing a tridimensional structured conduit, then repeat the ECM architecture and take advantage of MNPs internalized by cells and guide them through tension forces by external magnetic fields to stimulate and direct axon growing. The aims of this review were to evaluate the findings of studies that used physical stimuli (nanoscaffold surfaces and MNPs) used for peripheral nerve regeneration support. The future trends in the field of peripheral nerve regeneration continue to produce a wide variety of new techniques to improve the opportunity for advances to treat peripheral nerve injuries.