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Biosafety assessment of titanium dioxide nanoparticles in acutely exposed nematode Caenorhabditis elegans with mutations of genes required for oxidative stress or stress response
- Rui, Qi, Zhao, Yunli, Wu, Qiuli, Tang, Meng, Wang, Dayong
- Chemosphere 2013 v.93 pp. 2289-2296
- Caenorhabditis elegans, acute exposure, biosafety, genes, mutants, mutation, nanoparticles, oxidative stress, stress response, superoxide dismutase, titanium dioxide, toxicity
- We used Caenorhabditis elegans to investigate whether acute exposure to TiO2-NPs at the concentration of 20μgL−1 reflecting predicted environmental relevant concentration and 25mgL−1 reflecting concentration in food can cause toxicity on nematodes with mutations of susceptible genes. Among examined mutants associated with oxidative stress and stress response, we found that genes of sod-2, sod-3, mtl-2, and hsp-16.48 might be susceptible for TiO2-NPs toxicity. Mutations of these genes altered functions of both possible primary and secondary targeted organs in nematodes exposed to 25mgL−1 of TiO2-NPs for 24-h. Mutations of these genes caused similar expression patterns of genes required for oxidative stress in TiO2-NPs exposed mutant nematodes, implying their similar mechanisms to form the susceptible property. Nevertheless, acute exposure to 20μgL−1 of TiO2-NPs for 24-h and 25mgL−1 of TiO2-NPs for 0.48-h or 5.71-h did not influence functions of both possible primary and secondary targeted organs in sod-2, sod-3, mtl-2, and hsp-16.48 mutants. Therefore, our results suggest the relatively safe property of acute exposure to TiO2-NPs with certain durations at predicted environmental relevant concentrations or concentrations comparable to those in food in nematodes with mutations of some susceptible genes.