The effect of particles on tissue factor (TF) expression in THP-1 cells in mono- and co-cultures. A): TF expression is depicted by a histogram of flow cytometry analysis. B): The bar graph shows the percentage of TF positive cells. Data represent the means ± SEM; n = 3. **p < 0.01, a significant difference between compared groups. (c: control, FeNPs: Fe3O4 particles; SiNPs: SiO2 particles, EC: endothelial cells).