Metal oxide nanoparticles induce cytotoxic effects on human lung epithelial cells A549

Increasing in production and exposure to engineered nanoparticles (NPs), make necessary to acquire information about NP potential adverse health effects. Many studies, focused on NP toxicity, highlighted their cytotoxic potential but there is still a lack of information about the biological mechanisms involved. The aim of this research is the comparison of cytotoxicity between two types of metal nanoxides (CuO and TiO2) on A549 cells. After physico-chemical characterization, NPs were administered to cells. Cell-particle interactions, membrane integrity, viability and oxidative stress were investigated. CuO exposure resulted in a significant reduction of cell viability, while no effects were observed after TiO2 exposure. Both NPs induced cell cycle alteration, with a significant increase in frequency of cells in G1 and G2/M phases for TiO2 and CuO respectively. Confocal microscopy detected NPs at different cellular levels, and TEM imaging highlighted their ability to be internalized as aggregates by phagocytic processes or even as small agglomerates free in the cytoplasm.