Biodegradable Brain Stimulation Electrodes to Promote Translation Towards Stem-Cell Based Neural Repair Strategies

The delivery of electrical stimulation to the brain through implantable electrodes, referred to as brain stimulation, has been recognized as a clinically effective strategy for treating neurological disorders. Endogenous brain neural precursor cells (NPCs) have been shown to be electrosensitive cells that respond to electrical stimulation by (i) expanding in number, (ii) undergoing directed cathodal migration and (iii) differentiating into neural phenotypes <i>in vivo</i>, supporting the application of electrical stimulation to promote neural repair. In this study, we present the design of a flexible and biodegradable brain stimulation electrode for temporally regulated neuromodulation of NPCs. Leveraging the cathodally skewed electrochemical window of molybdenum and the volumetric charge transfer properties of conductive polymer, we engineered the electrodes with high charge injection capacity for the delivery of biphasic monopolar stimulation. We demonstrate that the novel electrodes are biocompatible and can deliver an electric field sufficient for NPC activation for 7 days post implantation before undergoing resorption in physiological conditions, thereby eliminating the need for surgical extraction. The biodegradable electrode demonstrated its potential to be used for NPC based neural repair strategies.