Aligned carbon nanotube reinforced polymeric scaffolds with electrical cues for neural tissue regeneration

Abstract

In this article, the challenge of providing electrical cue through a soft polymeric neural scaffold for directional neuron growth has been studied. Aligned multiwalled carbon nanotube (MWCNT) chitosan composite scaffolds are successfully fabricated using electric field alignment technique. Uniform distribution and alignment of 0.5 wt% MWCNTs in the chitosan matrix, good interfacial bonding, and aligned network of carbon nanotubes (CNTs) help to improve the elastic modulus, yield strength, and ultimate tensile strength by 12.7%, 21.9%, and 11.2%, respectively, as compared with the random MWCNT–chitosan scaffold. Alignment of MWCNTs introduces highly anisotropic electrical conductivity (100,000 times higher) along its direction, as compared to the transverse direction of the scaffold. This is the ideal requirement for a neural scaffold to guide cells in the appropriate direction. Interactions of HT-22 hippocampal neurons with MWCNT–chitosan matrix prove the scaffolds to be highly biocompatible with a notable increase in viability. In addition, 50–60% of neurons are found to be aligned in the MWCNT alignment direction of the scaffold. These results indicate that aligned MWCNT–chitosan scaffold is a potential design to control the directional cell migration on the scaffold, which opens up the possibility of its use in repopulating cells in regions of acute neuronal loss.