Figure 3

Measurement of intracellular ROS level and the associated changes in [Ca²⁺ ] _C . (A) RBL-2H3 cells were exposed to TiO₂ NPs at concentrations 0, 0.1, 0.25, 0.5 and 0.75 mg/ml. The generation of ROS was measured by fluorescence imaging. The level of ROS increased as a function of increasing TiO₂ NP concentration (n ≥ 50, **p < 0.005). (B) Pretreatment with antioxidant NAC (250 μM) significantly reduced the rise in cytosolic Ca²⁺ when stimulated with TiO₂ NPs. Each line is a representative fluorescence intensity of approximately 200 cells and the colors used are consistent with Figure 2A.