Probing cytotoxicity of nanoparticles and organic compounds using scanning proton microscopy, scanning electron microscopy and fluorescence microscopy

Scanning proton microscopy, scanning electron microscopy (SEM) and fluorescence microscopy have been used to probe the cytotoxicity effect of benzo[a]pyrene (BaP), ethidium bromide (EB) and nanoparticles (ZnO, Al₂O₃ and TiO₂) on a T lymphoblastic leukemia Jurkat cell line. The increased calcium ion (from CaCl₂) in the culture medium stimulated the accumulation of BaP and EB inside the cell, leading to cell death. ZnO, Al₂O₃ and TiO₂ nanoparticles, however, showed a protective effect against these two organic compounds. Such inorganic nanoparticles complexed with BaP or EB which became less toxic to the cell. Fe₂O₃ nanoparticles as an insoluble particle model scavenged by macrophage were investigated in rats. They were scavenged out of the lung tissue about 48 h after infection. This result suggest that some insoluble inorganic nanoparticles of PM (particulate matters) showed protective effects on organic toxins induced acute toxic effects as they can be scavenged by macrophage cells. Whereas, some inorganic ions such as calcium ion in PM may help environmental organic toxins to penetrate cell membrane and induce higher toxic effect.