THE USE OF FLUORESCENTLY LABELED NANOPARTICLES TO DETERMINE THE EFFECT OF PARTICLE SIZE ON TRANSLOCATION FROM THE LUNG.
Nanoparticles or ultrafine particles, are particles generally considered to be less than 100nm in size. These particles have been implicated in morbidity and other adverse reactions. Due to their small size, these particles may translocate from the lung to remote sites such as the heart, liver, brain or other extrapulmonary organs after inhalation exposure. Additionally, it has been suggested that the translocation of these particles may be responsible for adverse effects from ultrafine particles. Scientists at Procter & Gamble Co. have initiated studies to determine whether nanoparticles translocate to extrapulmonary organs after inhalation of particles in rats. Briefly, Fisher 344 female rats were exposed via an aspiration model to fluorescently labeled polystyrene ranging in size from 20 nm to 400 nm. Animals were sacrificed 1, 3, 7 and 14 days after exposure to nanoparticles. Lung, heart, brain, spleen, kidney and liver tissues were removed and preserved for histological examination. Blood was also collected for examination of nanoparticles. Tissue was examined via confocal microscopy for presence of fluorescent nanoparticles. In vitro experiments using EpiAirway tissue constructs were also performed to evaluate membrane/cell/particle interactions. Histological evaluations were performed on these tissues 2, 8, and 24 hours post exposure. In vivo experiments indicate a correlation between size and the ability of these particles to migrate from the lung after inhalation exposure. Additionally, (EpiAirway) in vitro data yielded similar findings indicating particle size is a factor in predicting translocation potential of nanosized particles.
Confocal microscopy, EpiAirway, Extrapulmonary organs, Inhalation exposure, Nanomaterials, Nanoparticles, Nanotechnology, Nanotoxicology, Translocation
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