Terahertz light to illuminate cell biology and cancer research

Scientists from the University of Liverpool are linking up to Europe's most intense terahertz light source at Daresbury's ALICE accelerator, with its state-of-the-art tissue culture centre and beamline to understand the effects of terahertz (THz) rays on human cells. This improved understanding of human cells could eventually lead to significant advances in human development and the understanding of diseases, including melanomas and esophageal cancer.

THz rays lie between microwaves and infrared light in the electromagnetic spectrum. THz light already has proven applications in both security devices and medical imaging and is already being used to detect hidden explosives, concealed weapons and drugs. Unlike traditional X-rays, terahertz radiation is considered intrinsically safe, in that it is non-destructive and non-invasive to human cells. However, scientists do not yet know what the safe upper limits for human exposure to this radiation are. A deeper understanding of THz rays' impact on living tissue will enable a new generation of medical and security imaging devices to be developed and used safely.

Professor Weightman, Principal Investigator from the University of Liverpool explained: "Like radio waves and visible light, THz rays are not expected to damage tissue like X-rays do. Our preliminary research at STFC Daresbury Laboratory has indicated that at low powers human cells appear to be unaffected by THz rays. However, the research carried out in this unique facility is the only way of establishing the safe limits of human exposure to THz radiation at high powers and what effect repeated low level exposure may or may not have on our bodies.

"The work will give us invaluable insight into the mechanisms of biological organisation and enable us to test a controversial theory of the mechanism by which biological systems organise themselves. This improved understanding of human cells could lead to significant advances in the diagnosis of diseases such as melanomas and esophageal cancer. Low power THz instruments are already used to analyze tissue removed in surgery because cancerous and healthy tissue respond differently to THz radiation. The research on ALICE will enable us to greatly improve these procedures and eventually lead to the development of improved low cost instruments for cancer diagnosis, although it is expected to be several years before these developments are realised. "

Dr Mark Surman, a research scientist at STFC Daresbury Laboratory added: "With ALICE we have an opportunity to irradiate living cells in a way that has never been done before, combining a high power source with a tissue culture facility. During Professor Weightman's research we expect to see about 70 kW of peak power in short pulses repeated tens of thousands of times every second. This means that the peak power will be thousands of times higher than other laboratory sources. Until now, ultra-high THz power sources have not been available to carry out this kind of research, so it is a major step forward that these trials on tiny samples of human tissue can now be carried out at ALICE."

ALICE is an R&D prototype for the next generation of accelerator-based light sources, and is based upon an unusual mode of operation for accelerators, known as energy recovery, where the energy used to create its high energy beam is captured and re-used after each circuit of the accelerator for further acceleration of fresh particles. This mode minimises the power needed to accelerate the beams, which at maximum level would otherwise require a small power station to operate. ALICE is the first accelerator in Europe to operate in this way.

ALICE accelerates to 26 million electron volts. Electrons are sent round the accelerator at 99.99% of the speed of light and 99.9% of the power at the final accelerator stage is recovered, making the power sources for the acceleration drastically smaller and cheaper and therefore economically viable.

The work is being carried out with funding from the Northwest Regional Development Agency and the Engineering and Physical Sciences Research Council (EPSRC).