More severe toxicity of gold nanoparticles with rougher surface in mouse hippocampal neurons

Gold nanoparticles (GNPs) have been extensively used in nanomedicine and neuroscience owing to their biological inertness, peculiar opto-electronic and physico-chemical features. However, the effect of GNPs shape on the neurophysiological properties of single neuron is still unclear. To tackle this issue, different shape GNPs (nanosphere, nanotriakisoctahedron and nanoflower) were synthesized to investigate the effect of GNPs on the voltage-dependent sodium channel and the action potential (AP) of hippocampal CA1 neurons in mice. The results indicated that GNPs inhibited the amplitudes of voltage-gated sodium current (I_Na) and led to a hyperpolarizing shift in the voltage-dependence curve of both activation and inactivation of I_Na. GNPs also increased neuronal excitability and altered some properties of AP. Moreover, most alterations in AP properties were observed in nanoflower GNPs treated CA1 neurons, suggesting that the neurotoxicity of gold nanoparticles is surface roughness-dependent. These results may provide a valuable direction in the clinical application of GNPs.