Figure 7
IL-8 expression by NP-conditioned media. A549 cells were exposed to conditioned media from NP-exposed differentiated THP-1 cells for 4 h. THP-1 cells were differentiated by treatment for PMA (10 ng/mL) and NPs were treated at surface area doses of 30, 100, and 300 cm2/mL except for ZnO NP (3, 10, and 30 cm2/mL) and CuO NP (0.3, 1, and 3 cm2/mL). (A) The levels of IL-8 in the conditioned media from THP-1 cells before addition of A549 cells. (B) The levels of IL-8 after addition of NP-free conditioned media to A549 cells. Values are mean ± SD from minimum four independent experiments. Significance versus vehicle control (VEH): *** p < 0.001.