Zinc Oxide Nanoparticles and Voltage-Gated Human K_v 11.1 Potassium Channels Interact through a Novel Mechanism

Membrane-nanoparticle interactions are important in determining the effects of manufactured nanomaterials on cell physiology and pathology. Here, silica, titanium, zinc, and magnesium oxide nanoparticles are screened against human hERG (K_v 11.1) voltage-gated potassium channels under a whole-cell voltage clamp. 10 µg mL^-1 ZnO uniquely increases the amplitude of the steady-state current, decreases the rate of hERG current inactivation during steady-state depolarization, accelerates channel deactivation during resurgent tail currents, and shows no significant alteration of current activation rate or voltage dependence. In contrast, ZnCl₂ causes increased current suppression with increasing concentration and fails to replicate the nanoparticle effect on decreasing inactivation. The results show a novel class of nanoparticle-biomembrane interaction involving channel gating rather than channel block, and have implications for the use of nanoparticles in biomedicine, drug delivery applications, and nanotoxicology.