Research Strategies for Safety Evaluation of Nanomaterials. Part VI. Characterization of Nanoscale Particles for Toxicological Evaluation

Abstract

To properly assign mechanisms or causes for toxic effects of nanoscale materials, their properties and characteristics both outside and within the biological environment must be well understood. Scientists have many tools for studying the size, shape, and surface properties of particulates outside of the physiological environment; however, it is difficult to measure many of these same properties in situ without perturbing the environment, leading to spurious findings. Characterizing nanoparticle systems in situ can be further complicated by an organism's active clearance, defense, and/or immune responses. As toxicologists begin to examine nanomaterials in a systematic fashion, there is consensus that a series of guidelines or recommended practices is necessary for basic characterization of nanomaterials. These recommended practices should be developed jointly by physical scientists skilled in nano characterization and biological scientists experienced in toxicology research. In this article, basic nanoparticle characterization techniques are discussed, along with the some of the issues and implications associated with measuring nanoparticle properties and their interactions with biological systems. Recommendations regarding how best to approach nanomaterial characterization include using proper sampling and measurement techniques, forming multidisciplinary teams, and making measurements as close to the biological action point as possible.

Implications of the stability behavior of zinc oxide nanoparticles for toxicological studies

“…Besides the preparation and characterization of the suspension, comprehensive powder characterization is essential for further investigations [20]. Concerning their powder properties, hydrophilic ZnO-hydro and hydrophobic ZnOlipo were very similar.…”

“…The link between protein corona and ZnO, particularly in view of its solubility should be further investigated. All in all, comprehensive characterization of the materials used is necessary for interpretation of toxicological results, as mentioned in numerous reviews [3,[20][21][22]. Especially the behavior of nanoparticles under physiological conditions must be considered to fully understand the interactions with components of the culture media [20].…”

Micromorphological cellular responses of MC3T3-E1 and RAW264.7 after exposure to water-dispersible silver nanoparticles stabilized by metal-carbon σ-bonds

“…their size, size distribution, shape, state of dispersion, physical and chemical properties, surface area and porosity, surface chemistry) and by cell characteristics (e.g. cell line, number of cells per well, and the period of culture before and/or after exposure to nanoparticles) 17,[24][25][26]29,30) . A recent study showed a decrease in MC3T3-E1 cell viability after exposure to Ag-NPs using the WST-8 assay 31) , but this study used different test conditions for cell culture and exposure to Ag-NPs, which may explain the disparity between their results and ours.…”

Characterization of solids in produced water from wells fractured with recycled and fresh water

“…Total Suspended Solids (TSS) are those solids in supracolloid and settleable size ranges. microscopy, and surface area measurements showed that the dynamic light scattering approach was preferred for nanoparticle size distribution testing in an aqueous environment (Powers et al, 2006). Section 3.1 and 3.2 discuss produced water sampling methods and suspended solid isolation protocols.…”