Magnetic nanochain-induced anisotropic nerve assembly for spinal cord injury repair

Utilizing neural tissue engineering scaffolds to improve and reconstruct the injury microenvironment has shown great promise for repairing spinal cord injury (SCI). Here, we present a type of magnetic nanochain-induced anisotropic nerve assembly for SCI repair. Under the magnetical drive, silica-coated magnetic nanoparticles assemble into highly stable nanochains, further integrated into the hydrogel and controlled by a magnetic field to form an anisotropic array in a three-dimensional space. In vitro studies confirm that the prepared anisotropic nanochain array exhibits good biocompatibility and can guide the directional growth of nerve cells and the elongation of neurites. Upon in vivo application, the anisotropic nanochain array is transplanted into a 2-mm-long SCI area of rats and successfully promotes the regeneration of new neurons and axons, together with the recovery of motor functions. These findings suggest that magnetic nanochain-induced anisotropic nerve assembly can be a viable option for SCI repair.