Technology Tethers Radicals

16 August 2011

School of Physics researchers, Professor Marcela Bilek and Professor David McKenzie, have developed a revolutionary new platform technology that is set to have a huge impact on areas as diverse as the early prediction of disease and the production of biofuels.

The breakthrough technology uses a layer of carbon and nitrogen, rich in free radicals, that anchors proteins to a surface. It is this easy and strong adherence of the biomolecules, while still preserving their function that has the science world buzzing.

"Free radicals are often thought of as 'bad guys' which, if allowed to run free in the body, are understood to be involved in degenerative diseases, biological aging and cancer. In our technology we're putting radicals to good use," says Professor McKenzie of the School of Physics.

The new technology will be of benefit to implantable medical devices such as stents. The breakthrough allows the surface to cloak itself in the patient's own protein, reducing the chance of medical complications such as inflammation and rejection. The patient's protein retains its "native" structure and will not trigger adverse reactions such as blood clots or the foreign body response.

"When proteins land on surfaces currently used in implants they unfold and distort, losing their biological function," explains Professor Bilek.

"When our surface is immersed in a fluid containing protein, the protein is bound by reacting with free radicals that are trapped in the surface's under-layer. The radicals do not harm the protein but tether them gently to the surface."

The new surfaces can be integrated into any material using a patented technology that prevents detachment even under extreme deformation, including during the stent expansion process when inserted in an artery.

The breakthrough technology can also be used for the early detection of diseases. "Antibodies can be anchored on the new surface in an array of spots," says Professor Bilek.

"Diseased cells attach themselves to the antibodies in characteristic patterns that enable the disease to be detected long before the symptoms emerge. This will allow early intervention and higher cure rates. We recently demonstrated diagnostic arrays which can detect diseased cells at levels lower than previously possible."

As well the platform technology will have an impact on biotechnology.

Professor McKenzie says that ethanol is a valuable fuel that could be produced from waste cellulose (cardboard and agricultural waste) with special enzymes that will be tethered to the new surface and continue to function. "This will enables new industrial production methods based on continuous flow rather than batch operation," he explains.

The paper: Free radical functionalization of surfaces to prevent adverse responses to biomedical devices by Marcela M. M. Bilek (School of Physics - SoP), Daniel V. Bax (SoP), Alexey Kondyurin (SoP), Yongbai Yin (SoP), Neil J. Nosworthy (SoP), Keith Fisher (School of Chemistry), Anna Waterhouse (School of Molecular Bioscience - SMB), Anthony S. Weiss (SMB), Cristobal G. dos Remedios, and David R. McKenzie (SoP) - all authors are from the University of Sydney - is published in the prestigious journal Proceedings of the National Academy of Sciences, USA.

Contact: Alison Muir

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