Nano(Q)SAR: Challenges, pitfalls and perspectives

Abstract

Regulation for nanomaterials is urgently needed, and the drive to adopt an intelligent testing strategy is evident. Such a strategy will not only provide economic benefits but will also reduce moral and ethical concerns arising from animal testing. For regulatory purposes, such an approach is promoted by REACH, particularly the use of quantitative structure–activity relationships [(Q)SAR] as a tool for the categorisation of compounds according to their physicochemical and toxicological properties. In addition to compounds, (Q)SAR has also been applied to nanomaterials in the form of nano(Q)SAR. Although (Q)SAR in chemicals is well established, nano(Q)SAR is still in early stages of development and its successful uptake is far from reality. This article aims to identify some of the pitfalls and challenges associated with nano-(Q)SARs in relation to the categorisation of nanomaterials. Our findings show clear gaps in the research framework that must be addressed if we are to have reliable predictions from such models. Three major barriers were identified: the need to improve quality of experimental data in which the models are developed from, the need to have practical guidelines for the development of the nano(Q)SAR models and the need to standardise and harmonise activities for the purpose of regulation. Of these three, the first, i.e. the need to improve data quality requires immediate attention, as it underpins activities associated with the latter two. It should be noted that the usefulness of data in the context of nano-(Q)SAR modelling is not only about the quantity of data but also about the quality, consistency and accessibility of those data.

• Nanotoxicology
• review
• QSAR

Acknowledgements

The authors would like to thank Stuart Hewlin (Procter and Gamble, UK) for his valuable assistance during the drafting of this article.

Declaration of interest

The authors declare no competing personal or financial conflicts.

The authors would like to thank the European Commission for financial support via the FP7 NanoReg and DEFRA UK (Department for Environment, Food and Rural Affairs). TP is grateful for the financial support of the European Commission through Marie Curie IRSES program, NanoBRIDGES project (FP7-PEOPLE-2011-IRSES, grant agreement number 295128), COST action TD1204: Modelling Nanomaterial Toxicity (MODENA) and Foundation for the Polish Science (FOCUS Program).

Any reference to a specific product, process or service does not constitute or imply an endorsement by National Physical Laboratory. The views and opinions expressed in this article are those of the authors and do not necessarily represent those of the National Physical Laboratory or NPL Management Limited.