Electrical stimulation of neural stem cells mediated by humanized carbon nanotube composite made with extracellular matrix protein.

One of the key challenges to engineering neural interfaces is to minimize their immune response toward implanted electrodes. One potential approach is to manufacture materials that bear greater structural resemblance to living tissues and by utilizing neural stem cells. The unique electrical and mechanical properties of carbon nanotubes make them excellent candidates for neural interfaces, but their adoption hinges on finding approaches for "humanizing" their composites. Here we demonstrated the fabrication of layer-by-layer assembled composites from single-walled carbon nanotubes (SWNTs) and laminin, which is an essential part of human extracellular matrix. Laminin-SWNT thin films were found to be conducive to neural stem cells (NSC) differentiation and suitable for their successful excitation. We observed extensive formation of functional neural network as indicated by the presence of synaptic connections. Calcium imaging of the NSCs revealed generation of action potentials upon the application of a lateral current through the SWNT substrate. These results indicate that the protein-SWNT composite can serve as materials foundation of neural electrodes with chemical structure better adapted with long-term integration with the neural tissue.