November 5, 2009

experts comment on new research into nanoparticles and DNA damage, as published in Nature Nanotechnology

The study investigates if and how particular nanoparticles can damage the DNA of cells without crossing cellular barriers.

Prof Eileen Ingham, Professor of Medical Immunology and Deputy Director of the Institute of Medical and Biological Engineering, University of Leeds, said:

“In this research a very simple model system was used in the lab to investigate whether particular nanoparticles can cause DNA damage to cells across a cell barrier. This model indicates that interesting cell biological mechanisms might be involved. It is not a model for what can happen in the body. It is important to note that the concentrations of nanoparticles studied in this research are far in excess of those that patients with medical implants may be exposed to.”

Prof Quentin Pankhurst, Director of the Davy-Faraday Research Laboratories, Royal Institution of Great Britain, said:

“The work here is of fundamental interest regarding signalling pathways and cellular responses, but it cannot be assumed that the conditions that were created in the laboratory in order to see these effects will ever be encountered in the human body. Toxicological studies are most reliably undertaken in vivo for the very good reason that it is virtually impossible to mimic, on a benchtop, the environment that drugs or any other injectable material will find when they enter a living body.”

Prof John Fisher, Deputy Vice-Chancellor and Director of the Institute for Medical & Biological Engineering, University of Leeds, said:

“This is a high quality basic science research describing interactions of nanoparticles with cells, however, the design of laboratory experiments and concentrations used means it is not relevant to the situation in patients and cannot be used to predict clinical effects or risks to patients.”

Dr Andrew D. Maynard, Chief Science Advisor, Project on Emerging Nanotechnologies, Woodrow Wilson International Center for Scholars, US, said:

“This is a study that raises an intriguing question – can foreign materials in the body cause harm across barriers like the placenta and the blood-brain barrier without actually crossing the barriers? Evidence is presented that suggests there is some possibility of this occurring. But the results should be treated with a high degree of caution until more is known.

“In particular:
-,The effects seen do not seem to be confined to nanoparticles alone. There is some evidence that even large particles containing Cobalt and Chromium – the two specific materials studied here – can exert their influence across barriers in the body.
-,No evidence is presented to suggest that this is a way in which all nanoparticles can cause harm, as opposed to the specific types of nanoparticles tested.
-,From these results, it is not possible to say whether the observed effects could occur under real-life conditions, or whether harm could be caused at realistic exposure levels. The concentrations of material used were very high – the equivalent of the placenta in a 9 months pregnant woman being exposed to approximately 4 – 40 grams of material. Whether such high exposures to materials like the ones used will ever occur is questionable.

“While the study opens up new avenues of research, and should be of particular interest to scientists developing new nanoparticle-based drugs and medical devices, it is too early to say whether materials in the body – including nanomaterials – are likely to cause damage across normally tight barriers like the placenta.”