Genotoxic impact of aluminum-containing nanomaterials in human intestinal and hepatic cells

Exposure of consumers to aluminum-containing nanomaterials (Al NMs) is an area of concern for public health agencies. As the available data on the genotoxicity of Al₂O₃ and Al⁰ NMs are inconclusive or rare, the present study investigated their in vitro genotoxic potential in intestinal and liver cell models, and compared with the ionic form AlCl₃. Intestinal Caco-2 and hepatic HepaRG cells were exposed to Al⁰ and Al₂O₃ NMs (0.03 to 80 μg/cm²). Cytotoxicity, oxidative stress and apoptosis were measured using High Content Analysis. Genotoxicity was investigated through γH2AX labelling, the alkaline comet and micronucleus assays. Moreover, oxidative DNA damage and carcinogenic properties were assessed using the Fpg-modified comet assay and the cell transforming assay in Bhas 42 cells respectively. The three forms of Al did not induce chromosomal damage. However, although no production of oxidative stress was detected, Al₂O₃ NMs induced oxidative DNA damage in Caco-2 cells but not likely related to ion release in the cell media. Considerable DNA damage was observed with Al⁰ NMs in both cell lines in the comet assay, likely due to interference with these NMs. No genotoxic effects were observed with AlCl₃. None of the Al compounds induced cytotoxicity, apoptosis, γH2AX or cell transformation.