The interaction of SiO2 nanoparticles with the neuronal cell membrane: activation of ionic channels and calcium influx

Aim: To clarify the mechanisms of interaction between SiO2 nanoparticles (NPs) and the plasmamembrane of GT1–7 neuroendocrine cells, with focus on the activation of calcium-permeable channels, responsible for the long lasting calcium influx and modulation of the electrical activity in these cells. Materials & methods: Nontoxic doses of SiO2 NPs were administered to the cells. Calcium imaging and patch clamp techniques were combined with a pharmacological approach. Results: Transient Receptor Potential V4, Connexins and Pannexin-like channels are the major components of the NP-induced inward currents. Preincubation with the antioxidant N-acetyl-L-cysteine strongly reduced the [Ca2+]i increase. Conclusion: These findings suggest that SiO2 NPs directly activate a complex set of calcium-permeable channels, pos- sibly by catalyzing free radicals production.