(592e) Oxide Nanoparticles Uptake in Human Lung Cells

Oxide nanoparticle uptake in human lung fibroblasts: Influence of agglomeration, diffusion and sedimentation at physiologically relevant concentrations.

Rapidly growing reports on novel applications of nanoparticles fail to alleviate the often cited public unease towards the invisible technology. Spectacular findings of nano-materials in the bodies of rats after exposure to carbon nanotubes or titania nanoparticles are in sharp contrast to a series of successful market introductions of consumer goods and slow legislation. During production or nanoparticle handling, dust uptake through the lung has raised concerns of asbestos-like toxic effects. Despite the prominence of oxide nanoparticles in the current research, exploration of their interactions with living cells remains at a very early stage. This reflects, in part, the inherent difficulties of detecting untreated nanoparticles at relevantly low concentrations.

We have therefore developed an analytical method to measure nanoparticle uptake in living human lung fibroblasts at physiologically relevant concentrations (100 ng ml-1). The oxide nanoparticles uptake was analyzed in time dependence with different size ranges and different exposure concentrations. Transmission electron microscopy showed that particles entered into the cells encapsulated by vesicles. Based on these quantitative uptake experiments a model for particle uptake was developed on the basis of physically measurable parameters.

The implication of quantitative nanoparticles uptake into human cells is further discussed in terms of possible adverse health effects and development of early toxicology indicators.

References: L.K Limbach, Y. Li, R.N. Grass, T.J. Brunner, M.A. Hintermann, M. Muller, D. Gunther, W.J Stark, Oxide nanoparticle uptake in human lung fibroblasts: Effects of particle size, agglomeration, and diffusion at low concentrations. Environmental Science & Technology 39, 9370-9376 (2005).

T.J. Brunner, P. Wick, P. Manser, P. Spohn, R.N. Grass, L.K. Limbach, A. Bruinink, W.J. Stark, In vitro cytotoxicity of Oxide Nanoparticles: Comparison to Asbestos, Silica, and effects of particle solubility. Environmental Science & Technology (2006), published online, 2006, DOI: 10.1021/es052069i

Fig 1: (left) Amount of ceria taken up by human lung fiboblasts vs. exposure time (right). Transmission electron micrograph of ceria nanoparticles entering a fibroblast cell.