Prussian Blue Nanoparticle-Mediated Scalable Thermal Stimulation for Neuronal Differentiation

Heating has been recently used as an alternative application to electrical stimulation to modulate excitability and to induce neuritogenesis and the expression of neuronal markers, but a long-term functional differentiation has not been described so far. Here we present the results obtained by a new approach for scalable thermal stimulation on the behavior of a model of dorsal root ganglion neurons, the F-11 cell line. Initially, we performed experiments of bulk stimulation in incubator for different time intervals and temperatures, and significant differences in neurite elongation and in electrophysiological properties were observed in cultures exposed at 41,5°C for 30 minutes. Thus, we exposed the cultures to the same temperature increase by irradiating, with a near infrared laser, a disc of Prussian Blue nanoparticles and poly-vinyl alcohol, that we stuck on the outer surface of the petri dish. In irradiated cells neurites were significantly longer and the electrophysiological properties (action potential firing frequency and spontaneous activity) were significantly increased compared to the control. These results suggest that a targeted thermal stimulation could be a promising technique to induce differentiation and support the future application of this method as a strategy to modify neuronal behavior in vivo.