Figure 3.

Pulmonary inflammation of six selected metal oxide nanomaterials (MeONPs) in mice. (A) Cytokine production ($\text{IL-}1\mathrm{\beta }$ and MCP-1) in BALF, and (B) H&E staining of lung tissues after 40 h exposure to MeONPs. C57Bl/6 mice ($n=6$) were exposed to ${\mathrm{La}}_2{\mathrm{O}}_3$, ${\mathrm{Gd}}_2{\mathrm{O}}_3$, ${\mathrm{Co}}_3{\mathrm{O}}_4$, ZnO, ${\text{TiO}}_2$, and ${\text{WO}}_3$ at $2\mathrm{mg}/\mathrm{kg}$ by oropharyngeal instillation. Quartz was used as positive control to treat animals ($5\mathrm{mg}/\mathrm{kg}$). After 40 h, animals were sacrificed to measure $\text{IL-}1\mathrm{\beta }$ and MCP-1 production in BALF by ELISA. The lung tissues were fixed for H&E staining (three sections for each mouse). Normal distribution was confirmed by Kolmogorov-Smirnov test ($\text{significance}>0.05$). *$p<0.05$ compared with vehicle control by two-tailed Student’s t-test.