Physico-chemical features of engineered nanoparticles relevant to their toxicity

Abstract

Nanotoxicology studies require investigations of several physico-chemical aspects of the particle/body fluid interaction, here described by reviewing recent literature in the light of new experimental data. Current characterization mostly covers morphology and metric-related characteristics (form, chemical composition, specific surface area, primary particle size and size distribution), and is mandatory in any experimental study. To unveil toxicity mechanisms, several other physico-chemical properties relevant to (geno) toxicity need to be assessed, typically the release or quenching of radical/ROS (Reactive Oxygen Species), the presence of active metal ions, evidence of structural defects. Major tasks for physical chemists working on nanoparticles-induced genotoxicity are described with some examples: (i), Tailored preparation of the same material in different sizes; (ii) particle modification changing a single property at a time; and (iii) identification of appropriate reference materials. Phenomena occurring during the contact between nanoparticles and cellular media or biological fluids (dispersion, agglomeration/aggregation, protein adsorption) are discussed in relation to the surface properties of the nanoparticles considered.

Keywords::

• Genotoxicity
• reference materials in nanotoxicology
• carbon nanotubes
• silica nanoparticles surface reactivity

Acknowledgements

The research has been carried out with the financial support of Regione Piemonte (CIPE 2006) Project “Nanoparticles: from their impact on the environment and human health to safer production and usage (NANOSAFE)” coordinated by Bice Fubini.

The experimental results reported are from ongoing studies within the Turin nanotoxicology group also including M. Tomatis, F. Turci (chemical basis in particle toxicology) and D. Ghigo and E. Gazzano (cell biochemistry). We are grateful to Dr S. Livraghi for the gift of a TiO₂ sample and to Dr V. Bolis for the TEM image of the pyrogenic silica. The Zeta potential data were obtained with the equipment acquired by the Interdepartmental Center “G. Scansetti” for Studies on Asbestos and Other Toxic Particulates with a grant from Compagnia di San Paolo, Torino.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.