DNA damage of macrophages at an air-tissue interface induced by metal nanoparticles

An air-tissue interface model was used to assess nanoparticulate-induced DNA damage to airway macrophages. Human Mono Mac 6 cells and rat alveolar macrophages were cultured on a collagen membrane and the deposition of metal nanoparticles in nitrogen enhanced using electrostatic charge. Cells were exposed to nanoparticles of iron, gold, silver for up to 10 min, then cultured in medium for 24 hours. Damage to DNA was assessed using the Comet assay. Nanoparticle dose delivered to cells varied with metal. Significant DNA damage to macrophages was induced by all three metal nanoparticles. Transmission electron microscopy showed deposition of discrete nanoparticles of gold and silver, but not iron. We conclude that an air-tissue model is a useful method for modelling DNA damage to airway cells from inhalation of metal nanoparticles.