title: Biodistribution of inhaled metal oxide nanoparticles mimicking occupational exposure: a preliminary investigation using enhanced darkfield microscopy.
abstract: Inhalation exposure to engineered nanomaterials (ENMs) may result in adverse pulmonary and/or systemic health effects. In this study, enhanced darkfield microscopy (EDFM) was used as a novel approach to visualizing industrial metal oxide nanoparticles (NPs) (silica, ceria, or alumina) in multiple tissue types following inhalation in rats mimicking occupational exposures. Advantages of EDFM over electron microscopy (EM) include reduced cost, time, and ease of sample preparation and operation. Following 4-6 hour inhalation exposures at three concentrations (3.5-34.0 mg/m3), lungs and secondary organs were harvested at 24 hours or 7 days post-exposure and prepared for brightfield (BF) microscopy and EDFM. NPs were visualized within the lung and associated lymphatic tissues and in major organs of excretion (liver, spleen, kidney). EDFM also revealed NPs within pulmonary blood vessels and localization within specific regions of toxicological relevance in liver and kidney, indicating pathways of excretion. Results demonstrate the utility of EDFM for rapid direct visualization of NPs in various tissue types and suggest the potential for metal oxide NPs to distribute to secondary tissues following inhalation exposure. Confirmation of the composition, distribution, and relative abundance of inhaled NPs will be pursued by combining EDFM with hyperspectral imaging (HSI) and mapping.
authors.affiliation: State University of New York (SUNY) Polytechnic Institute, College of Nanoscale Science, 257 Fuller Road, Albany, New York, 12203, United States.
authors.forename: Marissa
authors.initials: M
authors.lastname: Guttenberg
authors.affiliation: State University of New York (SUNY) Polytechnic Institute, College of Nanoscale Science, 257 Fuller Road, Albany, New York, 12203, United States.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Bezerra
authors.affiliation: State University of New York (SUNY) Polytechnic Institute, College of Nanoscale Science, 257 Fuller Road, Albany, New York, 12203, United States.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Neu-Baker
authors.affiliation: State University of New York (SUNY) Polytechnic Institute, College of Nanoscale Science, 257 Fuller Road, Albany, New York, 12203, United States.
authors.forename: María
authors.initials: M
authors.lastname: Del Pilar Sosa Idelchik
authors.affiliation: University of Rochester, Department of Environmental Medicine, 601 Elmwood Avenue, Rochester, New York, 14642, United States.
authors.forename: Alison
authors.initials: A
authors.lastname: Elder
authors.affiliation: University of Rochester, Department of Environmental Medicine, 601 Elmwood Avenue, Rochester, New York, 14642, United States.
authors.forename: Günter
authors.initials: G
authors.lastname: Oberdörster
authors.affiliation: State University of New York (SUNY) Polytechnic Institute, College of Nanoscale Science, 257 Fuller Road, Albany, New York, 12203, United States. sbrenner@sunypoly.edu.
authors.forename: Sara A
authors.initials: SA
authors.lastname: Brenner
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D019570:Inhalation Exposure; D053768:Metal Nanoparticles / Q000008:administration & dosage*; D008853:Microscopy; D016273:Occupational Exposure; D010087:Oxides; D051381:Rats; D014018:Tissue Distribution
chemical_list: D010087:Oxides
keywords: engineered nanomaterials; enhanced darkfield microscopy; histological samples; inhalation exposure