Joined: 16 Mar 2004
|Posted: Fri Aug 15, 2008 10:28 am Post subject: Polymer coating for nanoparticle safety
|27 September 2007 CosmeticsDesign
Polymer coating for nanoparticle safety
by Katie Bird
A polymer coating may protect against possible damage that could be caused by nanoparticles used in sunscreens, a scientific study suggests.
Nanoparticles are becoming increasingly popular in personal care products, particularly sunscreens, with the Woodrow Wilson nanotechnology consumer products inventory database counting over 27 sun care products.
However, the use of this technology is becoming increasingly controversial. Of particular concern is how the nanoparticles of sunscreen compounds such as titanium oxide react to UV radiation.
Research suggests that on exposure to UV light titanium oxide emits a photoelectron. It has been suggested that these photoelectrons could go on to catalyse the production of reactive oxygen species, which are known to react with DNA, causing damage.
However, a recent study, published in Chemical Communications, suggests that coating the titanium nanoparticles in a polymer may help protect against any damage that may be caused.
The scientists led by Miriam Rafailovich from the Stony Brook University, New York, coated the titanium nanoparticles in a mixture of antioxidant molecules from grape seed extracts, and an anionic polymer.
The coating appeared to absorb the photoelectron generated when the titanium nanoparticle was exposed to UV light, therefore blocking the catalytic activity that would lead to the reactive oxygen species.
However, there still remains significant uncertainty as to whether or not the use of nanoparticles is sunscreens requires cause for concern.
Kerry Hanson, form the University of California, Riverside, says that it is not clear whether or not titanium nanoparticles can penetrate the skin and the nucleur membrane.
Furthermore, even if they do penetrate the skin cells, it is unclear whether the UV light would be able to reach them and lead to the reactive oxygen species, Hanson explained.
A spokesperson for L'Oreal UK confirmed that their suncare products contain titanium particles as a sunscreen ingredient.
'This may be in a microparticle form, sometimes coated, to enhance the light filtering performance,' said the spokesperson, adding that 'We comply with all EU and national laws in ensuring the absolute safety of our products and their ingredients, which are clearly labelled on our products.'
However many campaigning groups remain unconvinced. For example, earlier this year Friends of the Earth released a report outlining some of the possible dangers of nanotechnology in sunscreens.
The report listed 'safe' nano-free products, and warned against the use of any sunscreen products containing nanoparticles. In addition, the organisation called for consumer action to help lobby the industry into a moratorium on nanotech-containing products until further research has been performed.