Figure 7 shows results of ADSCs undergoing transformation using only electrical stimulation. Electrical stimulation was performed using both nanofins and plain substrates. Although cells on plain substrate yielded a more confluent layer as compared to cells growing on nanofins, the cells receiving electrical stimulation via nanofins showed higher expression of NSC markers. 

Discussion

In summary, this paper reports on the development of an optimized nanoelectrode that has the potential to penetrate ADSCs without any loss of cellular function, where electrical stimulus can be applied through the penetrating electrodes to differentiate ADSCs into neuronal lineages. The nanofin design compared to nanopillars gave larger electrode surface area and thereby reduced the interfacial impedance and electrode resistance. Our preliminary studies show that electrical stimulation can greatly reduce the use of growth factor for cell differentiation with early expression of neural markers - Nestin and PAX6. In future, we hope to achieve an optimized  DC electrical stimuli protocol that may differentiate ADSCs without the use of growth factors.
We have demonstrated that DC ES promotes Vimentin, Nestin and Pax 6 expression in human ADSCs already at 5 days.
Future studies should look into finding the optimum parameters at which ES is not only most effective but can differentiate ADSC into desired cell type down the neural lineage.

Acknowledgements

This work was performed at the Joint School of Nanoscience and Nanoengineering, a member of Southeastern Nanotechnology Infrastructure Corridor (SENIC) and National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (ECCS-1542174).