In vitro investigation of immunomodulatory effects caused by engineered inorganic nanoparticles – the impact of experimental design and cell choice

Abstract

This study describes immunomodulatory effects of small inorganic nanoparticles and the impact of experimental design therein. Gold, cobalt oxide and iron oxide nanoparticles were synthesized in solution under conditions that ensured monodispersed and stable particles in solvents and when diluted in cell culture medium. Particles and solvents were tested for their cytotoxic and cytokine regulatory effects on immortalized and primary human lung epithelial cells in the absence and presence of the pro-inflammatory cytokine TNF-α. The particle-suspensions and solvents were not cytotoxic, but a significant effect on cytokine induction due to the chemical solvents was observed, although these are routinely used in nanoparticles synthesis. Significant immunomodulatory effects of some particle types on the immortalized epithelial cells were observed, these effects were more pronounced in primary epithelial cells. In conclusion, the solvent used to prepare the nanoparticles and the choice of cell type can affect the outcome of nanotoxicological studies.

• Lung epithelial cells
• immunomodulation
• inorganic nanoparticles

Acknowledgements

The authors thank Maria Schmittner for her technical assistance. Moreover, we would like to thank Dr Klaus Wittmaack for critical reading of the manuscript. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.