Membrane effects of zinc oxide nanorods and nanoparticles in human lymphocytes

Abstract

The study of the physical state of membrane lipids after the exposure of lymphocytes to ZnO NRs revealed a decrease in the lipid microviscosity of the hydrophilic membrane area and its increase in the hydrophobic area (external monolayer). The effects of ZnO NPs on membrane lipid components were not significant. Investigations of the membrane proteins conformation state revealed a rise of the protein NH 2 -groups level on the membrane surface only after the lymphocytes exposure to ZnO NRs. The level of SH-groups of the membrane protein after the action of ZnO NPs increased, otherwise the interaction of ZnO NRs with cells leads to the oxidation of thiol groups. According to the results of SEM, the geometric size of ZnO NPs did not exceed 30-100 nm, the diameter of ZnO NRs was 70-150 nm and the length - more than 500 nm. So the obtained results of toxicological tests can be partly explained by the possibility of ZnO NPs to enter into the cell but the most probable mechanisms for the NRs interaction with the cell are an electrostatic interaction or membrane puncturing.