title: Acute pulmonary toxicity and body distribution of inhaled metallic silver nanoparticles.
abstract: The purpose of this study was to determine the acute pulmonary toxicity of metallic silver nanoparticles (MSNPs, 20.30 nm in diameter). Acute pulmonary toxicity and body distribution of inhaled MSNPs in mice were evaluated using a nose-only exposure chamber (NOEC) system. Bronchoalveolar lavage (BAL) fluid analysis, Western blotting, histopathological changes, and silver burdens in various organs were determined in mice. Mice were exposed to MSNPs for 6 hrs. The mean concentration, total surface area, volume and mass concentrations in the NOEC were maintained at 1.93 × 10(7) particles/cm(3), 1.09 × 10(10) nm(2)/cm(3), 2.72 × 10(11) nm(3)/cm(3), and 2854.62 μg/m(3), respectively. Inhalation of MSPNs caused mild pulmonary toxicity with distribution of silver in various organs but the silver burdens decreased rapidly at 24-hrs post-exposure in the lung. Furthermore, inhaled MSNPs induced activation of mitogen-activated protein kinase (MAPK) signaling in the lung. In summary, single inhaled MSNPs caused mild pulmonary toxicity, which was associated with activated MAPK signaling. Taken together, our results suggest that the inhalation toxicity of MSNPs should be carefully considered at the molecular level.
authors.affiliation: Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea ; Current address: Risk Assessment Division, National Institute of Environmental Research, Incheon 404-708, Korea.
authors.forename: Jung-Taek
authors.initials: JT
authors.lastname: Kwon
authors.forename: Arash
authors.initials: A
authors.lastname: Minai-Tehrani
authors.forename: Soon-Kyung
authors.initials: SK
authors.lastname: Hwang
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Shin
authors.forename: Kyeong-Nam
authors.initials: KN
authors.lastname: Yu
authors.forename: Seung-Hee
authors.initials: SH
authors.lastname: Chang
authors.forename: Dae-Seong
authors.initials: DS
authors.lastname: Kim
authors.forename: Yong-Taek
authors.initials: YT
authors.lastname: Kwon
authors.forename: In-Ja
authors.initials: IJ
authors.lastname: Choi
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Cheong
authors.forename: Jun Sung
authors.initials: JS
authors.lastname: Kim
authors.forename: Myung-Haing
authors.initials: MH
authors.lastname: Cho
keywords: Distribution; Inhalation; Mitogen-activated protein kinase; Pulmonary toxicity; Silver nanoparticles