In vitro cytotoxicity and cellular uptake of gold nanoparticles

In vitro cytotoxicity and cellular uptake of gold nanoparticles

S284 Abstracts / Toxicology Letters 196S (2010) S37–S351 24 h exposure we found a slight DNA damage at the lower concentrations and a DNA damage sim...

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S284

Abstracts / Toxicology Letters 196S (2010) S37–S351

24 h exposure we found a slight DNA damage at the lower concentrations and a DNA damage similar to that found at the shorter times of exposure at 100 ␮g/mL MWCNTs. Moreover at the used MWCNTs concentrations a slight oxidative DNA damage induction was shown only after 4 h exposure. The results show cytotoxic effects in terms of LDH release and cell viability reduction after 24 h exposure to the highest MWCNTs concentration. The findings also show genotoxic effects induced on BEAS-2B cells by MWCNTs particularly after 2 and 4 h that decrease after 24 h suggesting the capability of this cellular type to repair DNA damage at low concentrations. The findings demonstrate the suitability of this experimental model to point out early cytotoxic/genotoxic effects induced on target organ by carbon nanotubes and furnish useful information for the evaluation of potential health risks of nanomaterials. doi:10.1016/j.toxlet.2010.03.1158

P303-038 In vitro toxicity assessment of silver nanoparticles in Chang liver cells and J-774 macrophages

exposing them to gold np with and without coating, and a gold salt as a control, for 10 days. Secondly, internalization of np in 3T3 cells was assessed by transmission electronic microscopy (TEM), in time kinetic. Results showed a higher sensitivity of stem cells when exposed to gold np coated with hyaluronic acid (IC50 3T3 = 2873 ␮g/mL and IC50 D3 = 852 ␮g/mL), while exposure to uncoated np showed higher sensitivity in differentiated cells (IC50 3T3 = 1757 ␮g/mL and IC50 D3 = 2632 ␮g/mL). Treatment with gold salts resulted in an IC50 almost equal for both cell lines (IC50 3T3 = 7.9 ␮g/mL and IC50 D3 = 7.7 ␮g/mL. TEM imaging revealed that at 15, 30 and 60 min there were no gold np inside the cells. For coated nanoparticles the entry started after 4 h, being completed by 24 h when all np were inside the lysosomes, some of which appeared damaged. In other way, uncoated nanoparticles were aggregated in the lysosomes after 4 h. This work suggests that the different presentations of np can have different responses in differentiated cells or stem cells. Moreover the onset of active internalization by the 3T3 fibroblast cell line can vary depending on nanoparticles’ coating, being completed after 4 or 24 h of exposition for uncoated or hyaluronic coated np respectively.

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

doi:10.1016/j.toxlet.2010.03.1160

1

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

P303-040 Exposure to nickel nanoparticles alters vascular reactivity in C57BL/6 mice

Silver nanoparticles have been widely used in medicinal and biological fields and little is yet known about their toxicity. In this study we evaluated the toxic effects of silver nanoparticles (2 nm) in Chang liver cells and J-774 macrophages. For toxicity evaluations cellular morphology, mitochondrial function (MTT assay), cell membrane viability (Neutral Red assay), reactive oxygen species production (DCFDA fluorescent probe), and nitric oxide production were assessed under control and exposed conditions. Cells were grown as monolayer in 96-well plates and exposed to 2–800 ␮g/mL for 24 h and 48 h. Results: The microscopic studies demonstrated that nanoparticle-exposed cells became abnormal in size, displaying cellular shrinkage and irregular shape. Silver nanoparticles produced cell oxidative stress and a significant viability decrease (60%) was observed in Chang liver cells exposed to 27 ␮g/ml. An increase of more than 5-fold of nitric oxide production was detected in macrophages exposed to 400 ␮g/ml. Silver nanoparticles induce a pro-oxidant environment in the cell suggesting that their cytotoxicity is likely to be mediated through oxidative stress.

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

2

doi:10.1016/j.toxlet.2010.03.1159

P303-039 In vitro cytotoxicity and cellular uptake of gold nanoparticles J. De Lapuente, D. Ramos, C. Porredon, C. Di Guglielmo, M. Borràs Parc Cientific, Barcelona, Spain In recent years, the extensive use of nanoparticles (np) is arising some questions about its toxicity and possible risks for human health. The high cost of experimentation in vivo and the development of in vitro alternative techniques are leading to a better knowledge of them. The aim of this work, encompassed in a broader project, was to know, first, the cytotoxicity in 3T3 fibroblasts and D3 stem cells

New York University, United States There is growing interest in engineered nanoparticles (NPs) for various medical and technological applications, but the long term environmental and health effects of these NPs (particles with a diameter <100 nm) are still being discovered. Since there have been associations reported between inhaled ambient ultrafine particles and increased risk of cardiopulmonary disease, it has been suggested that inhaled NPs may also induce adverse effects on the cardiovascular system. Acute exposure to nickel NPs, specifically has been suggested to induce pulmonary and systemic inflammation and, long term studies demonstrate exacerbation of atherosclerosis in apoprotein E knockout (ApoE KO) mice. However the exact mechanisms are not well understood. Few of these studies have specifically measured vascular function, specifically, arterial vasoconstriction and endothelial dysfunction. Nickel hydroxide nanoparticles (NH-NPs) were used as a test material and thoroughly characterized for various physicochemical properties related to toxicity. A series of preliminary inhalation studies were conducted using wild-type C57BL/6 mice to identify acute toxic potential of NH-NPs. Utilizing a whole body inhalation exposure system, C57BL/6 mice were exposed for 1 or 3 days to either NH-NPs (diameter of primary particle: 5 nm, count median diameter of agglomerates: approximately 40 nm) at approximately 150 ␮g Ni/cubic meter (approximately 10% of the current occupational standard), or to filtered air. Carotid arteries were isolated from each animal and 2 mm segments were mounted on a tension myograph system to measure contractile response. Compared to the filtered air exposed mice, no significant differences in the contractile response to phenylephrine (PE) was observed at either time point. However, at both time points, data indicates decreased relaxation after administration of acytelcholine (ACh) compared to the controls. The results suggest that short-term exposure to NH-NPs is associated with acute endothelial response and vasoconstric-