Physicist Dr Amanda Barnard has been using supercomputers to find the balance between sun protection and potential toxicity in a new generation of sunscreens which employ nanoparticles.

The metal oxide nanoparticles which block solar radiation are so small they cannot be seen, so the sunscreen appears transparent. But if the particles are too small, they can produce toxic levels of free radicals.

Amanda, who heads CSIRO’s Virtual Nanoscience Laboratory, has been able to come up with a trade-off—the optimum size of particle to provide maximum UV protection for minimal toxicity while maintaining transparency—by modelling the relevant interactions on a supercomputer.

This work, which was published in Nature Nanotechnology, won her the 2010 University of New South Wales Eureka Prize for Scientific Research. It’s one of a string of awards Amanda has accumulated in the past few years, most notably the 2009 Malcolm McIntosh Prize for Physical Scientist of the Year.

The awards highlight her fundamental research in using computers to develop nanomorphology—the science of structures and shapes of materials at the nano- or molecular scale and how this affects interactions with the surrounding environment.

In addition to investigating the health and safety implications of the growing use of nanoparticles in everyday products such as sunscreens, Amanda has also worked on a means of delivering drugs using electrically charged nanodiamonds. Animal trials have shown that this can decrease the amount of chemotherapy drug needed by about 20 times—reducing side-effects significantly. Amanda is also exploring the properties of fluorescent biolabels for use in cancer diagnosis and gene therapy, and of metal nanoparticles as fuel catalysts.

Photo: Amanda Barnard with one of her nanoparticle simulations

Credit: L’Oréal/SDP Photo

Virtual Nanoscience Laboratory, CSIRO, Amanda Barnard, Tel: +61 3 9545 7940, Amanda.Barnard@csiro.au, people.csiro.au/B/A/Amanda-Barnard.aspx