Inflammatory and genotoxic effects of nanoparticles designed for inclusion in paints and lacquers

Abstract

Manufactured nanomaterials are projected to be used on a large scale in paints and lacquers. We selected seven commercially interesting materials: Three titanium dioxide-based (two coated rutile; one uncoated anatase), one carbon black (Flamrüss 101), one kaolinite clay, and two silica products, whereas carbon black, Printex 90, was used as reference material. DNA damaging activity and inflammogenicity (pulmonary cell composition and mRNAs) were determined 24 h after intratracheal instillation of a single dose of 54 μg in mice. Greatest inflammation was induced by Printex 90 and uncoated titanium dioxide. The inflammatory potency correlated with instilled surface area (R² = 0.94) but not with material volume (R² = 0.17). The coated titanium dioxides induced DNA damage in lung lining fluid cells. The uncoated titanium dioxide was not DNA damaging by the comet assay 24 h after exposure despite being highly inflammogenic. This suggests that inflammation is not a prerequisite to DNA damage in titanium dioxide-based products.

Keywords::

• Inflammation
• DNA damage
• nanoparticles
• paints
• lacquers

Acknowledgements

The technical assistance from Lourdes Pedersen, Elzbieta Christiansen, Michael Guldbrandsen, Maria Hammer and Vivi Kofoed-Sørensen is gratefully acknowledged. The Danish Paint and Lacquer Organization and especially the following Danish paint companies kindly supplied the materials: Flügger, Beck & Jørgensen, Dyrup, Akzo Nobel and Boesens Fabrikker. The experiments were approved by the Danish “Animal Experimental Inspectorate” and carried out following their guidelines for ethical conduct and care when using animals in research.

Declaration of interest: The Danish Working Environment Research Fund supported the study (Nanokem, grant #20060068816). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.