title: Development and evaluation of an aerosol generation and supplying system for inhalation experiments of manufactured nanoparticles.
abstract: Risk assessment of nanoparticles by inhalation experiments is of great importance since inhalation is considered the most significant route of exposure to nanoparticles suspended in air. However, there have been few inhalation experiments using manufactured nanoparticles, mainly because of the difficulty in stably dispersing the nanoparticles in air for a long period of time. In this study, we report for the first time the development of a rational system for stably and continuously dispersing and supplying manufactured nanoparticles for inhalation experiments. The system was developed using a spray-drying technique, in which a nebulizer was used to atomize nickel oxide (NiO) and fullerene (C60) nanoparticle suspensions, and the resulting droplets were dried to generate aerosol nanoparticles. The size, concentration and morphology of the aerosol particles were evaluated by in-line measurements using an aerosol measuring device and off-line measurements based on the collection of the aerosol particles. After examining the effects of the conditions for the suspensions and the aerosol generation, we were able to obtain NiO and C60 aerosol nanoparticles with average diameters of 53-64 and 88-98 nm, respectively. By feeding these aerosols into a whole-body exposure chamber for rats, a stable supply of the aerosol nanoparticles could be achieved for long hourly durations (6 h per day) as well as for long terms (5 days per week for 4 weeks).
authors.affiliation: Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan. smd@hiroshima-u.ac.jp
authors.forename: Manabu
authors.initials: M
authors.lastname: Shimada
authors.forename: Wei-Ning
authors.initials: WN
authors.lastname: Wang
authors.forename: Kikuo
authors.initials: K
authors.lastname: Okuyama
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Myojo
authors.forename: Takako
authors.initials: T
authors.lastname: Oyabu
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Isamu
authors.initials: I
authors.lastname: Tanaka
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Endoh
authors.forename: Kunio
authors.initials: K
authors.lastname: Uchida
authors.forename: Kensei
authors.initials: K
authors.lastname: Ehara
authors.forename: Hiromu
authors.initials: H
authors.lastname: Sakurai
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Junko
authors.initials: J
authors.lastname: Nakanishi
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols / Q000008:administration & dosage*; D000818:Animals; D037741:Fullerenes / Q000008:administration & dosage / Q000737:chemistry; D019570:Inhalation Exposure; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000648:ultrastructure; D009330:Nebulizers and Vaporizers; D009532:Nickel / Q000008:administration & dosage / Q000737:chemistry; D010316:Particle Size; D051381:Rats
chemical_list: D000336:Aerosols; D037741:Fullerenes; D009532:Nickel; C028007:nickel monoxide