Pyrolized 3D Carbon Scaffolds and Electrical Stimulation Enhance Differentiation of Neurons

Abstract

In recent years, carbon materials have been increasingly utilized in biomedical applications. The use of carbon has several advantages: carbon microstructures are inexpensive and easy to fabricate, they have tunable surface properties, and 3-D carbon microstructures can be fabricated to mimic the in vivo biological environment. In this work, pyrolyzed three-dimensional carbon micropillar electrodes are used as a substrate to electrically stimulate and grow mouse neuronal stem cells (NSC’s). The micropillar electrodes are fabricated by controlled pyrolysis of SU-8, a polymeric photoresist. NSC’s are seeded on the micropillar array and daily DC electrical stimulation is applied. Application of 10 mV of DC electrical stimulation for 15 minutes a day is shown to increase differentiation of NSCs toward dopaminergic lineages and to increase neurite outgrowth when compared to NSC’s grown on conventional tissue culture plates. Furthermore, a microfluidic disc is used to create a controlled flow of byproducts from differentiated NSCs toward a detection chamber. A separate, three dimensional carbon interdigitated electrode array, also fabricated using SU-8 and conventional photolithography techniques, is placed into the detection chamber and uses redox amplification to selectively detect dopamine. The success of the 3D carbon micropillar electrodes in inducing spontaneous differentiation of NSC's toward dopaminergic lineages, along with the implementation of electrochemical detection of dopamine on a microfluidic disc, demonstrates the efficiency of the platform as a stem cell culture and detection device.