The structural development of primary cultured hippocampal neurons on a graphene substrate.

The potential of graphene-based nanomaterials as a neural interfacing material for neural repair and regeneration remains poorly understood. In the present study, the response to the graphene substrate by neurons was determined in a hippocampal culture model. The results revealed the growth and maturation of hippocampal cultures on graphene substrates were significantly improved compared to the commercial control. In details, graphene promoted growth cone growth and microtubule formation inside filopodia 24h after seeding as evidenced by a higher average number of filopodia emerging from growth cones, a longer average length of filopodia, and a larger growth cone area. Graphene also significantly boosted neurite sprouting and outgrowth. The dendritic length, the number of branch points, and the dendritic complex index were significantly improved on the graphene substrate during culture. Moreover, the spine density was enhanced and the maturation of dendritic spines from thin to stubby spines was significantly promoted on graphene at 21 days after seeding. Lastly, graphene significantly elevated the synapse density and synaptic activity in the hippocampal cultures. The present study highlights graphene's potential as a neural interfacing material for neural repair and regeneration and sheds light on the future biomedical applications of graphene-based nanomaterials.