Response of Alveolar Epithelial Cells exposed to Zinc Oxide Nanoparticles: Comparison of Exposure under Air-liquid Interface or Submerged Conditions

Introduction: Inhalation of zinc oxide (ZnO) nanoparticles (NPs) has been associated with pro-inflammatory responses in the lung. However, dosimetric uncertainties limit the relevance of exposures conducted under submerged culture conditions and especially for airborne NPs, cell exposure at the air-liquid-interface (ALI) is more realistic. Methods: A549 cells were exposed to ZnO NPs under both submerged and ALI culture conditions. The cellular response was characterized by measuring mRNA expression (qRT-PCR) of the pro-inflammatory cytokine IL-8 and the oxidative stress marker hemeoxygenase-1 (HO-1). Results: Im…