The Toxicologist - Society of Toxicology

model of lung inflammation and host defense. We established a murine pulmonary
infection model of Klebsiella pneumoniae (K.p.) to determine if lung bacterial clearance
is enhanced or impaired by Cu NP exposure using two different exposure
routes, sub-acute inhalation (4 h/d, 10 d) and intratracheal instillation (3, 35, and
100 μg/mouse). Pulmonary response was evaluated by cell enumeration, lung
histopathology, total protein, lactate dehydrogenase (LDH) activity, and inflammatory
cytokines in bronchoalveolar lavage (BAL) fluid. Cu-exposed mice induced inflammatory
responses with increased recruitment of total cells and neutrophils to
the lungs as well as increased total protein and LDH activity in BAL fluid.
Inflammatory cytokines in BAL fluid increased dramatically including: IL-6, IL-12,
GM-CSF, KC, MCP-1, MIP-1α and TNF-α. Both inhalation and instillation exposure
to Cu NPs significantly decreased the pulmonary bacterial clearance of K.p.exposed
mice measured 24 h after bacterial infection (10 5 CFUs/mouse) following
Cu NP exposure versus sham-exposed mice also challenged with K.p. We observed
Cu NP exposure impaired host defense against bacterial lung infections and a dosedependent
effect of instilled Cu NPs on bacterial clearance in which even our lowest
dose demonstrated significantly lower clearance than observed in sham-exposed
mice. Thus, Cu NP exposure may lead to increased risk of pulmonary infection due
to impaired host defense against bacteria.
1475 MAGNETIC PARTICLE DETECTION (MPD) FOR RAPID
CELL & TISSUE DOSIMETRY.
K. R. Minard 1, 4 , B. D. Thrall 1, 4 , J. G. Teeguarden 1, 4 , M. H. Littke 1, 4 , V. B.
Mikheev 2, 4 and W. Wang 3, 4 . 1 Pacific Northwest National Laboratory, Richland, WA,
2 Battelle, Richland, WA, 3 Oak Ridge National Lab., Oak Ridge, TN and 4 B-FAST,
Battelle Center for Fundamental and Applied Systems Toxicology, Columbus, OH.
Magnetic nanoparticles are of widespread interest for disease diagnosis, therapy,
monitoring treatment, and understanding how different material properties affect
biodistribution and toxicity. Nevertheless, accurate measurements of particle
amounts in cells, blood and tissue remain a major challenge. To provide accurate
dosimetry for emerging applications, we have developed and tested a new detection
platform for quickly and easily determining the mass of superparamagnetic
nanoparticles in small sample volumes (~250 ul). Measurements use an oscillating
magnetic field (100 Gauss/250 kHz), require no sample preparation, are inexpensive
to implement, and takes less than a second. Instrument calibrations performed
using aqueous suspensions of 15 nm iron oxide (Fe 3 O 4 ) cores with different surface
coatings (plain, carboxyl (-COOH), or amine (-N(CH 3 ) 3 ) exhibit excellent correlation
(R 2 ~0.99) between detector output and total particle mass. Data further
demonstrates that detection limits are typically less than ~100 ng, and that sensor
output is insensitive to particle agglomeration or testing matrix (cell, media, or tissue).
Results from in vitro studies show that the uptake of carboxyl-coated iron oxides
in RAW 264.7 macrophages is nearly six-fold lower in knockouts with a 90%
lower expression of the scavenger receptor, and that uptake is well described by a
particokinetic model that accounts for experimental conditions. To demonstrate ex
vivo dosimetry, excised mouse tissues were analyzed after a 4 hr exposure to
aerosolized Fe 3 O 4 -COOH having a count median aerodynamic diameter of ~70
nm & a concentration of ~1900 ug/m 3 . Results highlight rapid lung clearance over
a 7-day period, and in combination with other findings, demonstrate MPD’s broad
utility for important dosimetry applications. Funded by NIBIB R21 EB008192,
NHLBI R01 HL073598, NIEHS R01 ES016212 and Battelle Memorial Institute.
1476 SYNTHESIS, CHARACTERIZATION, AND TOXICITY
STUDIES OF DISCRETE SIZE NANOPARTICLE-
PESTICIDE CONJUGATE FOR NOVEL PESTICIDE
DELIVERY.
A. Sooresh, H. Kwon, P. Pietrantonio, M. Pine and C. Sayes. Texas A&M
University, College Station, TX.
Extensive research has been done on the synthesis, characterization and toxicity
studies of silver nanoparticles. The current literature suggests that silver in a
nanoparticulate form induces little adverse effects; therefore nanosilver has the potential
to be utilized in a variety of environmental applications. This work proposes
a novel synthetic scheme to produce a nanoparticle-pesticide conjugate to be used
as an active agent against insect vectors such as mosquitoes. Monodispersed silver
nanoparticles were synthesized by chemically reducing a silver salt and then conjugated
to deltamethrin, a synthetic pyrethroid pesticide, resulting in a stable colloidal
suspension. This pesticide encapsulated nanoparticle (PEN) was characterized
using a variety of techniques including UV-Visible Spectroscopy, Dynamic
Light Scattering (DLS), Transmission Electron Microscopy (TEM), Energy
Dispersive X-ray Spectroscopy (EDS) and Inductively Coupled Plasma Mass
Spectroscopy (ICP-MS). The newly developed PEN was tested on mosquitoes to
assess their mortality and behavior. Data from the mosquito bioassay confirms that
PEN is lethal to mosquitoes after a 24 hour exposure. These results demonstrate the
potential to use nanoparticle surfaces in disease prevention. In particular, the
nanoparticle-pesticide conjugates will find wide applications as they can be impregnated
into bed nets, clothing and household fabrics, as well as paints and other
coatings, to help prevent disease and potentially decrease human exposure to toxic
chemicals. Currently, cultured cell lines are being utilized to assess the cytotoxicity
of PEN on mammalian systems.
1477 NANOPARTICLE TOXICITY ON AIRWAY EPITHELIAL
CELLS.
M. M. McCorkel 1, 2 and S. Boitano 1, 2, 3 . 1 Biomedical Engineering, University of
Arizona, Tucson, AZ, 2 Arizona Respiratory Center, Arizona Health Sciences Center,
Tucson, AZ and 3 Physiology, University of Arizona, Tucson, AZ. Sponsor: R. Lantz.
There are strong correlations between ultrafine particle deposition in the lung and
chronic respiratory illness. The emergence of engineered nanoparticles (ENPs) and
their growing prevalence in society presents a new potential lung toxicant exposure
with limited known effects on lung health. Recent research on chronic obstructive
pulmonary disease associated with ultrafine particle deposition has uncovered a key
role for dysregulation of paracrine ATP signaling and corresponding innate immune
function. We hypothesized that ENP exposure on lung cells may affect ATP
response in the lung epithelium and this would limit cell adhesion and migration
during wound repair. We examined ATP signaling and compromise of innate immune
function in cultured human airway epithelial cells (16HBE14o-) following
exposure to nano-sized (20 nm) hafnium oxide (HfO 2 ) as a model ENP. After incubation
with low doses of HfO 2 (50 and 250 mg/L), cells were examined with
high-throughput real time cell analysis (RTCA) assays and digital imaging video
microscopy to evaluate changes in ATP-induced cell signaling, cell adhesion, cell
migration and wound repair. Lung epithelial cells displayed an altered response to
ATP, reduced cell adhesion, cell migration and wound repair following 24 hr exposure
to HfO 2 . These results suggest that low doses of HfO 2 alter a basic innate immune
function in lung epithelial cells that could contribute to respiratory disease.
1478 TRANSPORT MECHANISM OF NANOPARTICLE INTO
THE BRAIN.
B. Choi, D. Kim and J. Park. Preventive Medicine, Chung-Ang University, Seoul,
Republic of Korea.
Nanomaterials can be used in various biomedical and cosmetic applications, however,
the neurotoxicity of these materials was poorly understood. Purpose of the
present study was to establish the in vitro blood-brain barrier(BBB), blood-CSF
barrier(BCB) models and in situ brain perfusion technique to screen the transport
of nanomaterials into the brain. We also performed a transport study using in vitro
with silver nanoparticle (AgNP) and different size gold nanoparticles (AuNPs) and
did a transport study using in situ method with AgNP. We established the in vitro
BBB and BCB models which was used co-culture method with ECV304 cell and
C6 glioma cell and was used with Z310 cell, respectively. Silver (Ag) and gold (Au)
ion uptake was higher than AgNP and AuNPs in BBB and BCB models. In BBB
model, the permeability of AuNPs was found to be depending on particule size. Ag
uptake was higher than AgNP in situ brain perfusion and Ag and AgNP transport
into the brain were mainly achieved through the BBB. These results were similar in
vitro study results. Taken together, these data suggest that in vitro BBB model can
be used to a screening test for nanomaterials transport into the brain and the
smaller sized AuNPs can be transported into the brain easily.
1479 EMBRYONIC GENE EXPRESSION IS IMPACTED BY
SURFACE FUNCTIONALITIES OF GOLD
NANOPARTICLES.
L. Truong 1, 2 , T. Zaikova 2, 3 , J. Miller 2, 3 , J. Hutchison 2, 3 and R. Tanguay 1, 3 .
1 Environmental & Molecular Toxicology, Oregon State University, Corvallis, OR,
2 The Oregon Nanoscience and Microtechnologies Institute and the Safer
Nanomaterials and Nanomanufacturing Initiative, Eugene, OR and 3 Chemistry,
University of Oregon, Eugene, OR.
Gold nanoparticles (AuNPs) that were cationic-functionalized, N,N,N trimethylammoniumethanethiol
(TMAT), or anionic- functionalized, 2-mercaptoethanesulfonate
(MES), with identical 1.5nm core sizes produced differential developmental
responses in a sensitive embryonic zebrafish assay. To investigate the
molecular mechanisms underlying the differential toxic responses, global gene expression
studies were conducted using NimbleGen zebrafish microarrays. RNA was
isolated from embryonic zebrafish exposed to the 100% effective concentrations
(EC100s) for 1.5nm TMAT-AuNPs (50 ppm) and MES-AuNPs (10 ppm) at 24
SOT 2011 ANNUAL MEETING 317