Research

Gold nanoparticles induce cytotoxicity in the alveolar type-II cell lines A549 and NCIH441

Chiara Uboldi¹ , Daniele Bonacchi² , Giada Lorenzi² , M Iris Hermanns¹ , Christine Pohl¹ , Giovanni Baldi² , Ronald E Unger¹ and C James Kirkpatrick¹

¹  Institute of Pathology – REPAIR Lab, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55101 Mainz, Germany

²  CERICOL – Centro di Ricerche Colorobbia, Via Pietramarina 123, 50059 Firenze, Italy

author email corresponding author email

Particle and Fibre Toxicology 2009, 6:18doi:10.1186/1743-8977-6-18

Published:	22 June 2009

Abstract

Background

During the last years engineered nanoparticles (NPs) have been extensively used in different technologies and consequently many questions have arisen about the risk and the impact on human health following exposure to nanoparticles. Nevertheless, at present knowledge about the cytotoxicity induced by NPs is still largely incomplete. In this context, we have investigated the cytotoxicity induced by gold nanoparticles (AuNPs), which differed in size and purification grade (presence or absence of sodium citrate residues on the particle surface) in vitro, in the human alveolar type-II (ATII)-like cell lines A549 and NCIH441.

Results

We found that the presence of sodium citrate residues on AuNPs impaired the viability of the ATII-like cell lines A549 and NCIH441. Interestingly, the presence of an excess of sodium citrate on the surface of NPs not only reduced the in vitro viability of the cell lines A549 and NCIH441, as shown by MTT assay, but also affected cellular proliferation and increased the release of lactate dehydrogenase (LDH), as demonstrated by Ki-67 and LDH-release assays respectively. Furthermore, we investigated the internalization of AuNPs by transmission electron microscopy (TEM) and we observed that particles were internalized by active endocytosis in the cell lines A549 and NCIH441 within 3 hr. In addition, gold particles accumulated in membrane-bound vesicles and were not found freely dispersed in the cytoplasm.

Conclusion

Our data suggest that the presence of contaminants, such as sodium citrate, on the surface of gold nanoparticles might play a pivotal role in inducing cytotoxicity in vitro, but does not influence the uptake of the particles in human ATII-like cell lines.