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 plasma membrane 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: TRPV4, Cx and Panx-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, possibly by catalyzing free radical production.