Widespread nanoparticle-assay interference: implications for nanotoxicity testing

PLoS One. 2014 Mar 11;9(3):e90650. doi: 10.1371/journal.pone.0090650. eCollection 2014.

Abstract

The evaluation of engineered nanomaterial safety has been hindered by conflicting reports demonstrating differential degrees of toxicity with the same nanoparticles. The unique properties of these materials increase the likelihood that they will interfere with analytical techniques, which may contribute to this phenomenon. We tested the potential for: 1) nanoparticle intrinsic fluorescence/absorbance, 2) interactions between nanoparticles and assay components, and 3) the effects of adding both nanoparticles and analytes to an assay, to interfere with the accurate assessment of toxicity. Silicon, cadmium selenide, titanium dioxide, and helical rosette nanotubes each affected at least one of the six assays tested, resulting in either substantial over- or under-estimations of toxicity. Simulation of realistic assay conditions revealed that interference could not be predicted solely by interactions between nanoparticles and assay components. Moreover, the nature and degree of interference cannot be predicted solely based on our current understanding of nanomaterial behaviour. A literature survey indicated that ca. 95% of papers from 2010 using biochemical techniques to assess nanotoxicity did not account for potential interference of nanoparticles, and this number had not substantially improved in 2012. We provide guidance on avoiding and/or controlling for such interference to improve the accuracy of nanotoxicity assessments.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Assay* / standards
  • Humans
  • Nanoparticles / adverse effects*
  • Nanoparticles / chemistry
  • Nanoparticles / ultrastructure
  • Particle Size

Grants and funding

This work was supported by grants from the NNBNI Initiative (Grant #RES0002319), Environment Canada, and NRC. K.J.O. and J.D.E. were supported by both NSERC Vanier and Alberta Innovates Graduate Student Scholarships, V.A.O. was supported by an NSERC graduate student scholarship, and T.J.M. was supported by an NSERC PDF scholarship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.