Separation, Sizing, and Quantitation
of Engineered
Nanoparticles in an Organism Model Using Inductively Coupled Plasma
Mass Spectrometry and Image Analysis
Monique E. Johnson
Shannon K. Hanna
Antonio R. Montoro Bustos
Christopher M. Sims
Lindsay C. C. Elliott
Akshay Lingayat
Adrian C. Johnston
Babak Nikoobakht
John T. Elliott
R. David Holbrook
Keana C. K. Scott
Karen E. Murphy
Elijah J. Petersen
Lee L. Yu
Bryant C. Nelson
10.1021/acsnano.6b06582.s001
https://acs.figshare.com/articles/journal_contribution/Separation_Sizing_and_Quantitation_of_Engineered_Nanoparticles_in_an_Organism_Model_Using_Inductively_Coupled_Plasma_Mass_Spectrometry_and_Image_Analysis/4499111
For
environmental studies assessing uptake of orally ingested engineered
nanoparticles (ENPs), a key step in ensuring accurate quantification
of ingested ENPs is efficient separation of the organism from ENPs
that are either nonspecifically adsorbed to the organism and/or suspended
in the dispersion following exposure. Here, we measure the uptake
of 30 and 60 nm gold nanoparticles (AuNPs) by the nematode, Caenorhabditis elegans, using a sucrose density gradient
centrifugation protocol to remove noningested AuNPs. Both conventional
inductively coupled plasma mass spectrometry (ICP-MS) and single particle
(sp)ICP-MS are utilized to measure the total mass and size distribution,
respectively, of ingested AuNPs. Scanning electron microscopy/energy-dispersive
X-ray spectroscopy (SEM/EDS) imaging confirmed that traditional nematode
washing procedures were ineffective at removing excess suspended and/or
adsorbed AuNPs after exposure. Water rinsing procedures had AuNP removal
efficiencies ranging from 57 to 97% and 22 to 83%, while the sucrose
density gradient procedure had removal efficiencies of 100 and 93
to 98%, respectively, for the 30 and 60 nm AuNP exposure conditions.
Quantification of total Au uptake was performed following acidic digestion
of nonexposed and Au-exposed nematodes, whereas an alkaline digestion
procedure was optimized for the liberation of ingested AuNPs for spICP-MS
characterization. Size distributions and particle number concentrations
were determined for AuNPs ingested by nematodes with corresponding
confirmation of nematode uptake <i>via</i> high-pressure
freezing/freeze substitution resin preparation and large-area SEM
imaging. Methods for the separation and <i>in vivo</i> quantification
of ENPs in multicellular organisms will facilitate robust studies
of ENP uptake, biotransformation, and hazard assessment in the environment.
2016-12-16 00:00:00
Engineered Nanoparticles
acidic digestion
hazard assessment
Image Analysis
sucrose density gradient centrifugation protocol
removal efficiencies
Caenorhabditis elegans
AuNP removal efficiencies
particle number concentrations
SEM imaging
size distribution
60 nm gold nanoparticles
multicellular organisms
vivo quantification
60 nm AuNP exposure conditions
nematode uptake
plasma mass spectrometry
digestion procedure
Organism Model
Size distributions
water rinsing procedures
spICP-MS characterization
Plasma Mass Spectrometry
sucrose density gradient procedure
ENP uptake
Au-exposed nematodes
noningested AuNPs