Multi-walled carbon nanotubes inhibit regenerative axon growth of dorsal root ganglia neurons of mice

► Multi-walled carbon nanotubes (MWCNTs) inhibited regenerative axon growth in dorsal root ganglia cultures. ► MWCNT exposure decreased axon length and axon branching, without cell death. ► MWNCTs may have detrimental effect on regenerative axon growth and may potentially trigger axonal pathology. Recent observations have demonstrated that nanomaterials may be toxic to human tissue. While the ability of nano-scaled particulate matter is known to cause a range of problems in respiratory system, recent observations suggest that the nervous system may be vulnerable as well. In the current paper we asked whether exposure of primary neuronal cell cultures to nanoparticles might compromise regenerative axon growth. Regenerative response was triggered by performing a conditioning lesion of sciatic nerve five days prior to collection of dorsal root ganglia (DRG). DRG neurons were plated at a low density and incubated with multi-walled carbon nanotubes (MWCNTs) (0.1–10 μg/ml in 10% of surfactant in saline) overnight. The experiments showed that exposure of DRG cultures to MWCNT significantly impaired regenerative axonogenesis without concomitant cell death. These results indicate that MWNCTs may have detrimental effect on nerve regeneration and may potentially trigger axonal pathology.