Development of reference metal and metal oxide engineered nanomaterials for nanotoxicology research using high throughput and precision flame spray synthesis approaches

Abstract

There is a growing need to develop and characterize reference metal and metal oxide engineered nanomaterials (ENMs) of high purity and tunable intrinsic properties suitable for nanotoxicology research. Here a high throughput (volume) and precision flame spray pyrolysis (FSP) approach coupled with state-of-the-art characterization techniques are utilized to generate such reference ENMs. The lab-based and industrially relevant FSP system, termed as Versatile Engineered Nanomaterials Generation System (VENGES), synthesizes the metals and metal oxides, at high throughput manner with controlled properties, such as primary particle size, aggregate diameter, shape, crystallinity, stoichiometry and surface chemistry. A nanopanel of nine reference ENMs (silica, silver, silver supported on silica, alumina, ceria and iron oxide) was synthesized and characterized using combined electron microscopy, advanced spectroscopic techniques and physical analyses (, BET, XRD, TEM, pycnometry, XPS, ICP-MS and FTIR). ENMs show a high degree of chemical purity and stoichiometry, and low content of carbon residuals, and are sterile and free of bacteria and endotoxins. Further, their colloidal properties and their implication in dosimetry have been also investigated in both environmental and test biological media. The suitability of reference ENMs and protocols developed in this study brings forth new arenas to generate reliable and reproducible toxicological data in an effort to reduce conflicting and contradicting inter-laboratory data on relative toxic effects of ENMs.

Synthesis of Precision Gold Nanoparticles Using Turkevich Method

“…The detailed work of Turkevich and his coworkers (Turkevich J. et al, 1951) has become one of the milestones of AuNPs synthesis. Since then, the synthesis method has been modified and improved (Frens G., 1973) for a diverse area of interests including the development of chemical sensors for water quality analysis using surface enhanced Raman spectroscopy (SERS) (Tian F. et al, 2014), surface-induced catalytic activities (Lopez N. et al, 2004;Xie W. et al, 2012), drug delivery in biological systems (Ghosh P. et al, 2008;Saallah S. and Lenggoro I.W., 2018) and nano-toxicology studies (Beltran-Huarac J. et al, 2018;Somasundaran P. et al, 2010;Grobmyer S.R. and Moudgil B.M., 2010;Pyrgiotakis G. et al, 2018).…”

Analysis of lipid adsorption on nanoparticles by nanoflow liquid chromatography-tandem mass spectrometry

“…[ 34 , 35 ] Commercially available food grade TiO2 E171 was purchased from an online retailer. The particles were characterized in terms of size, shape, crystallinity, density, surface area, porosity, purity, surface chemistry, endotoxins and biological contaminants according to the protocols described by Beltran et al [34]. The results are summarized in the Electronic Supplementary Material (ESM) (Tables S1–S3, Figs.…”

Pulmonary toxicity assessment following aerosolization of engineered nanomaterials using an in vitro air-liquid interface method

“…ISO has published standard parameters to define particulate shapes in document 13321:1996 E and 22412. In this thesis, primary particle shapes of citrate Au, 16% AgSiO2 and CuO NPs were defined using Transmission Electron Microscopy (TEM) for aspect ratio, circularity, and roundness [108][109][110][111][112].…”

“…To avoid the problem of agglomeration, we could apply shear forces for example sonication, grinding and turbulent forces to redisperse particles. In this thesis, ENMs were sonicated under appropriate time and amplitude according to the formula provided [108][109][110][111][112].…”

“…Although there has not been an agreement upon a strict characterization protocol for nanotoxicology studies, consensus has evolved regarding which properties should be evaluated Table 1.1 [10]. For this thesis, materials were produced and characterized by our cooperative group in Engineered-nanomaterials Resource Coordination Core (ERCC) at Harvard School of Public Health [108][109][110][111][112]. For connecting ENMs characteristics to their toxicity, it is critically important to think about how these properties relate to toxicity at the cellular level, and the reason behind them.…”