Recent research at the US Department of Energy’s Pacific Northwest National Laboratory (PNNL) in Richland, Washington, provides further evidence to suggest that total surface area rather than size, mass or number of particles may be the most appropriate metric in relation to the toxicity of some types of nanoparticles. This supports similar conclusions reached by the EC Scientific Committee in its Opinion on the appropriateness of existing risk assessment methodologies published on 29 March 2007.

Being aware of the difficulties in agreeing on the most relevant nanoparticle dose unit to use to measure toxicity, Brian Thrall and colleagues at PNNL studied the dose of amorphous silica nanoparticles required to cause a biological response. Using particle number or mass as a dose metric their results were inconsistent but by calculating the total surface area they were able to predict a biological response which appeared also, in the study, to vary little according to the size of the nanoparticles.

Source: Pacific Northwest National Laboratory

Posted: March 4th, 2009 under Safety and risk, Nanomedicine.
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Researchers at the University of Rochester Medical Centre have published a recent paper that provides strong evidence that some types of nanoparticles with dimensions under 10nm can pass directly through the skin.

The team, led by Lisa DeLouise, used quantum dots that fluoresce when exposed to light and which are therefore easier to track. The work has potential significance in both studies of nanoparticle safety and in designing transdermal drug delivery systems.

Further information available at Physorg.Com.

Posted: October 2nd, 2008 under Safety and risk, Nanomedicine.
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