S etters

2ctMw

ccBaD

mtf

d

PIl

LR

1

2

S

Slsi

frnce

nip(Adct

d

PI

J

Ishok

t

284 Abstracts / Toxicology L

4 h exposure we found a slight DNA damage at the lower con-entrations and a DNA damage similar to that found at the shorterimes of exposure at 100 �g/mL MWCNTs. Moreover at the used

WCNTs concentrations a slight oxidative DNA damage inductionas shown only after 4 h exposure.

The results show cytotoxic effects in terms of LDH release andell viability reduction after 24 h exposure to the highest MWCNTsoncentration. The findings also show genotoxic effects induced onEAS-2B cells by MWCNTs particularly after 2 and 4 h that decreasefter 24 h suggesting the capability of this cellular type to repairNA damage at low concentrations.

The findings demonstrate the suitability of this experimentalodel to point out early cytotoxic/genotoxic effects induced on

arget organ by carbon nanotubes and furnish useful informationor the evaluation of potential health risks of nanomaterials.

oi:10.1016/j.toxlet.2010.03.1158

303-038n vitro toxicity assessment of silver nanoparticles in Changiver cells and J-774 macrophages

. Garza-Ocanas 1, M. Ramirez-Cabrera 1, M.T. Zanatta-Calderon 1,. Lujan-Rangel 1, D.A. Ferrer 2, M.J. Yacaman 3

Fac de Medicina Universidad Autonoma de Nuevo Leon, Mexico,The University of Texas at Austin, USA, 3 The University of Texas atan Antonio, USA

ilver nanoparticles have been widely used in medicinal and bio-ogical fields and little is yet known about their toxicity. In thistudy we evaluated the toxic effects of silver nanoparticles (2 nm)n Chang liver cells and J-774 macrophages.

For toxicity evaluations cellular morphology, mitochondrialunction (MTT assay), cell membrane viability (Neutral Red assay),eactive oxygen species production (DCFDA fluorescent probe), anditric oxide production were assessed under control and exposedonditions. Cells were grown as monolayer in 96-well plates andxposed to 2–800 �g/mL for 24 h and 48 h.

Results: The microscopic studies demonstrated thatanoparticle-exposed cells became abnormal in size, display-

ng cellular shrinkage and irregular shape. Silver nanoparticlesroduced cell oxidative stress and a significant viability decrease60%) was observed in Chang liver cells exposed to 27 �g/ml.n increase of more than 5-fold of nitric oxide production wasetected in macrophages exposed to 400 �g/ml. Silver nanoparti-les induce a pro-oxidant environment in the cell suggesting thatheir cytotoxicity is likely to be mediated through oxidative stress.

oi:10.1016/j.toxlet.2010.03.1159

303-039n vitro cytotoxicity and cellular uptake of gold nanoparticles

. De Lapuente, D. Ramos, C. Porredon, C. Di Guglielmo, M. Borràs

Parc Cientific, Barcelona, Spain

n recent years, the extensive use of nanoparticles (np) is arisingome questions about its toxicity and possible risks for human

ealth. The high cost of experimentation in vivo and the devel-pment of in vitro alternative techniques are leading to a betternowledge of them.

The aim of this work, encompassed in a broader project, waso know, first, the cytotoxicity in 3T3 fibroblasts and D3 stem cells

196S (2010) S37–S351

exposing them to gold np with and without coating, and a gold saltas a control, for 10 days. Secondly, internalization of np in 3T3 cellswas assessed by transmission electronic microscopy (TEM), in timekinetic.

Results showed a higher sensitivity of stem cells when exposedto gold np coated with hyaluronic acid (IC50 3T3 = 2873 �g/mLand IC50 D3 = 852 �g/mL), while exposure to uncoated np showedhigher sensitivity in differentiated cells (IC50 3T3 = 1757 �g/mL andIC50 D3 = 2632 �g/mL). Treatment with gold salts resulted in anIC50 almost equal for both cell lines (IC50 3T3 = 7.9 �g/mL and IC50D3 = 7.7 �g/mL. TEM imaging revealed that at 15, 30 and 60 minthere were no gold np inside the cells. For coated nanoparticles theentry started after 4 h, being completed by 24 h when all np wereinside the lysosomes, some of which appeared damaged. In otherway, uncoated nanoparticles were aggregated in the lysosomesafter 4 h.

This work suggests that the different presentations of np canhave different responses in differentiated cells or stem cells. More-over the onset of active internalization by the 3T3 fibroblast cellline can vary depending on nanoparticles’ coating, being completedafter 4 or 24 h of exposition for uncoated or hyaluronic coated nprespectively.

doi:10.1016/j.toxlet.2010.03.1160

P303-040Exposure to nickel nanoparticles alters vascular reactivity inC57BL/6 mice

A. Cuevas, E. Liberda, L.C. Chen

New York University, United States

There is growing interest in engineered nanoparticles (NPs) forvarious medical and technological applications, but the long termenvironmental and health effects of these NPs (particles with adiameter <100 nm) are still being discovered. Since there havebeen associations reported between inhaled ambient ultrafine par-ticles and increased risk of cardiopulmonary disease, it has beensuggested that inhaled NPs may also induce adverse effects onthe cardiovascular system. Acute exposure to nickel NPs, specif-ically has been suggested to induce pulmonary and systemicinflammation and, long term studies demonstrate exacerbation ofatherosclerosis in apoprotein E knockout (ApoE KO) mice. How-ever the exact mechanisms are not well understood. Few ofthese studies have specifically measured vascular function, specifi-cally, arterial vasoconstriction and endothelial dysfunction. Nickelhydroxide nanoparticles (NH-NPs) were used as a test materialand thoroughly characterized for various physicochemical prop-erties related to toxicity. A series of preliminary inhalation studieswere conducted using wild-type C57BL/6 mice to identify acutetoxic potential of NH-NPs. Utilizing a whole body inhalation expo-sure system, C57BL/6 mice were exposed for 1 or 3 days toeither NH-NPs (diameter of primary particle: 5 nm, count mediandiameter of agglomerates: approximately 40 nm) at approximately150 �g Ni/cubic meter (approximately 10% of the current occupa-tional standard), or to filtered air. Carotid arteries were isolatedfrom each animal and 2 mm segments were mounted on a tensionmyograph system to measure contractile response. Compared tothe filtered air exposed mice, no significant differences in the con-tractile response to phenylephrine (PE) was observed at either time

point. However, at both time points, data indicates decreased relax-ation after administration of acytelcholine (ACh) compared to thecontrols. The results suggest that short-term exposure to NH-NPsis associated with acute endothelial response and vasoconstric-