Conductivity of nanomaterial modulates neuronal excitability via enhanced astrocytic passive conductance and glutamate uptake

While conductive nanomaterials have primarily been studied for neuronal modulation, their effects on astrocytic physiology and the underlying physicochemical determinants remain largely unexplored. In particular, how conductivity, along with other physicochemical properties, is linked to astrocyte function remains unclear. We engineered conductive and non-conductive nanotube platforms with comparable nanotopographies, differing in conductivity and material composition. Both platforms enhanced primary astrocyte adhesion, consistent with their shared nanotopography. However, only the conductive platform was associated with increased intracellular Ca 2+ activity. Elevated Ca 2+ coincided with enhanced glutamate uptake on the conductive platform. Astrocytic passive conductance was also increased on conductive substrates, accompanied by elevated TASK1 expression. Consistently, whole-cell patch-clamp recordings revealed a reduced neuronal firing probability in slices incubated with conductive nanotube, whereas non-conductive substrates had no effect. Collectively, this study highlights conductivity as a physicochemical parameter associated with astrocytic functional modulation and neuron-glia interaction, suggesting the potential of glia-targeted nanomaterial strategies.