Fig. 3
Adhesion of U937 cells to HUVECs. U937 cells were exposed to TNFα (10 ng/mL) or to concentration of 0.3, 1, 3, 10, 30 and 100 μg/mL of TiO2 NPs of 50 nm during 3 h. Unexposed cultures were used as negative controls. After 3 h of exposure, the cells were co-cultured with HUVEC that may be naive or exposed to TiO2 NPs. a U937 cells exposed to TiO2 NPs and naive HUVECs; b HUVEC and U937 cells exposed to the same concentrations of TiO2-NP; c HUVEC exposed to TiO2-NP and naive U937 cells. The results were similar under all experimental conditions. * p < 0.05 vs negative control