Figure 1.

NPs can cause disruption of membrane integrity causing small or large holes. They can generate ROS, cause lysosome damage, increase intracellular [Ca²⁺] levels and induce apoptosis. Assays that were employed to study these effects and particles with significant action in these assays are indicated. Only effects recorded in concentrations up to 100 µg ml⁻¹ for 24 h and up to 750 µg ml⁻¹ for 30 s as used in Ca²⁺ imaging are mentioned. DHE, dihydroethidium; ECS, Extracellular space; ICS, intracellular space; LDH, lactic dehydrogenase; ROS, reactive oxygen species.