New model for nanoparticle lung exposure sheds new light on possible health risks
A new model for nanoparticle exposure should provide more realistic insights into the possible health risks of airborne nanoparticles, researchers in Switzerland claim.
The team investigated cerium oxide nanoparticles and although no toxicity was found, changes in the function of the cell were noted after 30 minutes of exposure - such as a breakdown in communication between cells and possible DNA damage.
Nanoparticles have many potential uses in medicine and technology, so detailed assessments of any dangers they might pose is crucial. Typical toxicity studies use nanoparticles suspended in solution, but these can form clumps or behave differently to those in a real-world environment.
In an effort to make a more accurate simulation, scientists at the Universityof Bern and the Swiss Federal Institute of Technology (ETH) in Zurich designed a sealed glovebox system where nanoparticles are simultaneously made in aerosol form and then deposited onto lung tissue cells.
’We wanted to build a lab model that’s as close as possible to reality,’ says Robert Grass, who worked on the project, noting that the box also contains a water bath and several electronic counters. This setup allows fresh nanoparticles to made and directly exposed to cultured lung tissue - more accurately rendering how nanoparticle exposure might occur in industry.
’This is a bold study that represents a step forward for in-vitro toxicology testing,’ says Gary Hutchison, an expert in nanoparticle toxicity at Edinburgh Napier University, UK. ’This method to disperse the particles appears to make them fall on tissue in a more natural manner.’
The sealed glovebox system has the potential to investigate any type of nanoparticle, but the Swiss team initially chose cerium oxide as it has rapidly growing uses for polishing and computer chip manufacture.
’The study has already produced some interesting results,’ Gary Hutchison told Chemistry World. ’After only 30 minutes of exposure, the nanoparticles appeared to be altering some cell functions - affecting communication between cells, for example.’ In addition, levels of 8-oxoguanine increased, which is an indicator for reactive oxygen species inducing DNA damage - although more study will be required to verify this.
One question that remains difficult to answer is how much risk is posed by long-term exposure to nanoparticles, with recent studies suggesting that carbon nanotubes have a similarity to aspestos fibres. But Hutchison is confident that a nanotechnology health scare is unlikely - since toxicology testing is advancing hand-in-hand with new nanoparticle developments.
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2. C A Poland et al, Nature Nanotechnology, 2008. DOI: 10.1038/nnano.2008.111
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