Fig. 4

Biological functions of human RBCs after TiO₂ NPs treatments. After isolated human RBCs were treated with various concentrations (0, 5, 10 and 25 μg/mL) of TiO₂ NPs for 24 h at 37 °C, (a) procoagulant activity was shown by a concentration-dependent trend of thrombin generation using prothrombinase assay and (b) enhanced adherent RBCs to HUVECs was detected by fluorescence microscope as described in Methods. Endothelial cells (green fluorescence); RBCs (red fluorescence). Required further confirmation in the following study (white arrow). (b, right) The increased intensity shown as a bar graph was the fluorescence of red color, reflecting the relatively adherent RBCs to HUVECs. (c) RBC aggregation (white arrows) was initiated by 24 h treatment with TiO₂ NPs as observed by fluorescence microscopy. Scale bar: 50 μm. Values are mean ± S.E. of 4 independent experiments, * represents significant differences from the control group (p < 0.05)