Development and evaluation of an aerosol generation and supplying system for inhalation experiments of manufactured nanoparticles.
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).
Shimada
Manabu
M
Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan. smd@hiroshima-u.ac.jp
Wang
Wei-Ning
WN
Okuyama
Kikuo
K
Myojo
Toshihiko
T
Oyabu
Takako
T
Morimoto
Yasuo
Y
Tanaka
Isamu
I
Endoh
Shigehisa
S
Uchida
Kunio
K
Ehara
Kensei
K
Sakurai
Hiromu
H
Yamamoto
Kazuhiro
K
Nakanishi
Junko
J
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
D000336:Aerosols; D037741:Fullerenes; D009532:Nickel; C028007:nickel monoxide