Abstract
The objective of this study is whether or not cerium dioxide (CeO2) nanoparticle has the pulmonary toxicity. We performed inhalation and intratracheal instillation studies using same sample of cerium oxide nanoparticles, and examined the pulmonary inflammation in both studies. In intratracheal instillation study, rats were exposed to 0.2 mg or 1 mg of CeO2. In inhalation study, rats were exposed to inhaled CeO2 ( 2.1 mg/m3; low concentration, 10.2 mg/m3; high concentration ) for 4 weeks ( 6 hours/day, 5 days/week). Cell analysis and chemokines in bronchoalveolar lavage fluid (BALF) were analyzed at 3 days, 1month and 3 months after end of exposure in both studies.
Inhalation studies showed that neutrophil number was increased in BALF of low and high concentration groups, and peaked on the 1 month. Intratracheal instillation studies also showed that neutrophil number in BALF was increased, reached a peak level of 1 week, and returned to negative control level at 6 months. If these endpoints of inflammation data by CeO2 nanoparticle were compared with previous data by nickel oxide nanoparticle (high inflammatory potentials) and titanium dioxide nanoparticles (low inflammatory potentials), the level of inflammation by CeO2 nanoparticle was approximately between nickel oxide and titanium dioxide nanoparticles. Taken together, we suggested that the inflammatory potentials of CeO2 nanoparticle may be intermediate.
This work is partially supported by “Development of innovative methodology for safety assessment of industrial nanomaterials" by Ministry of Economy, Trade and Industry (METI) of Japan.
- Copyright ©ERS 2015
