Figure 9
Cellular dose-response due to ZnO nanoparticle exposure under submerged and air-liquid interface conditions. The dose-dependent IL-8 (pro-inflammatory) and HO-1 (oxidative stress) mRNA expression in A549 cells was measured with qRT-PCR after ZnO exposure in the ALICE (3 h post-exposure incubation period; control: 10 mM citrate) and under submerged conditions (for 3 h; control: pure medium). Reported are the geometric mean and standard deviation (n>3). None of the responses was statistically significant below 1.0 μg/cm2. For larger doses, significant differences between ALICE and submerged responses were observed.