Toxicity of binary mixtures of Al₂O₃ and ZnO nanoparticles toward fibroblast and bronchial epithelium cells

ABSTRACT

The objective of this study was to examine the cytotoxic effects of binary mixtures of Al₂O₃ and ZnO NPs using mouse fibroblast cells (L929) and human bronchial epithelial cells (BEAS-2B) as biological test systems. The synergistic, additive, or antagonistic behavior of the binary mixture was also investigated. In toxicity experiments, cellular morphology, mitochondrial function (MTT assay), apoptosis, nuclear size and shape, clonogenic assays, and damage based upon oxidative stress parameters were assessed under control and NPs exposure conditions. Although Abbott modeling results provided no clear evidence of the binary mixture of Al₂O₃ and ZnO NPs exhibiting synergistic toxicity, some specific assays such as apoptosis, nuclear size and shape, clonogenic assay, activities of antioxidant enzymatic enzymes catalase, superoxide dismutase, and levels of glutathione resulted in enhanced toxicity for the mixtures with 1 and 1.75 toxic units (TU) toward both cell types. Data demonstrated that co-presence of Al₂O₃ and ZnO NPs in the same environment might lead to more realistic environmental conditions. Our findings indicate cytotoxicity of binary mixtures of Al₂O₃ and ZnO NPs produced greater effects compared to toxicity of either individual compound.

KEYWORDS:

• Binary toxicity
• nanoparticles
• aluminum oxide
• zinc oxide
• in vitro cytotoxicity

Acknowledgments

We would like to thank the staff of the Central Laboratory of Electron Microscopy (LCME) and Multiuser Laboratory of Biology Studies (LAMEB) at the Federal University of Santa Catarina, Florianópolis, SC, Brazil for assistance with microscopy analysis.

Declaration of interest

The authors report no conflicts of interest. The authors are solely responsible for the content and writing of this article.

Supplementary material

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Additional information

Funding

This work was funded by the National Council for Scientific and Technological Development (CNPq) and Coordination of Improvement of Higher Education Personnel (CAPES).