June 11, 2009

expert reaction to paper on nanoparticles to be published in Journal of Molecular Cell Biology

Scientists have for the first time identified a mechanism by which nanoparticles cause lung damage, and shown that such damage can be blocked with a targeted chemical compound.

Prof Ken Donaldson, Professor of Respiratory Toxicology, University of Edinburgh, said:

“This is a paper that is of academic/therapeutic interest only in that the PAMAM nanoparticles that were studied are purpose-made by the nanomedical industry for injection into patients to deliver drugs or image disease state. There will never be an accidental exposure to PAMAM particles as an airborne dust, nor will they be eaten or put into a cosmetic. They have to be injected, by a doctor, although, from the outcome of this study, I doubt that they will be used for delivering drugs to the lungs, as they seem to cause lung cell death.

“The problem is that all nanoparticles are lumped together as if they are one thing and they most certainly are not. These PAMAM particles are from a class of highly specialised nanoparticles made by the drug industry in tiny amounts for delivery into the human body; by contrast other nanoparticles are made industrially in tons for adding to paints or putting into hockey sticks. Clearly there is potential for workers and the public being accidentally exposed to the latter but not the former.

“The authors looked at a range of PAMAM nanoparticles of different types and found only the positively charged ones were toxic. It is well known that positively charged particles are toxic to the lungs, so this is not really news to particle toxicologists.”