Cell-by-Cell Treatments Based on Optical Tweezing

New, noninvasive surgical techniques using ultrasound and laser technology to deliver cell-by-cell medical treatments could be applied to cancer and gene therapies.

Physicists Paul Campbell of the University of Dundee and Kishan Dholakia at the University of St. Andrews (Fife, Scotland), have each been awarded more than £1 million to develop the technique by the UK Basic Technology Programme, administered by the Engineering and Physical Sciences Research Council.

The basis of the new technology involves a somewhat unexpected property of light: When sharply focused, it can actually exert a tangible force on real, albeit microscopic, objects. The sharply focused light can act like a miniaturized hand, "grabbing" hold of tiny objects and moving them to other locations -- a process known as optical tweezing. Using this process, the scientists can gather arrays of cells and load them with molecules of choice, such as DNA or another therapeutic agent.

The grant announcement follows preliminary research by the Dundee-St. Andrews collaboration in the past year that resulted in a breakthrough in 2005 in understanding how cancer cells can be targeted and destroyed by a single pulse of ultrasound energy, using a 'sniper rifle' approach developed from military technology.

Campbell and Dholakia, together with colleagues at their the institutions, are developing the techniques to create tools they said will revolutionize the delivery of genes, drugs and therapeutic molecules to single cells and tissue samples.

The ultrasound-based approach the scientists explored in the 'sniper rifle' project last year has now been augmented by a new technique developed at St. Andrews using laser technology.

"This dual approach technology allows us, in principle, to inject any molecule into any cell," Dholakia said. "Indeed, we have shown that even genetic material can be introduced into cells using the laser-based approach with successful downstream biological effects.”

The combination ultrasonic and photonic technology "promises to deliver a quantum leap" for biologists studying the cell’s chemical pathways or signals, the researchers said. They plan to combine the most useful aspects of both the ultrasound and laser techniques into an automated benchtop device for laboratory use.

Campbell said, "The overriding objective for this project is to revolutionize the activation and delivery of genes, drugs and therapeutic molecules into live biological materials. Developing a means to controllably deliver drugs at remote anatomical sites, yet in a very noninvasive fashion, is a significant challenge of heightened academic and industrial interest. This is underscored by the market for delivery technologies, which is estimated to be around 30 billion dollars in the USA alone."

The Universities of Dundee and St. Andrews jointly host the Institute of Medical Science and Technology, a research and development initiative concentrating on interface science (between biology, physics and engineering) for future interventional medical technologies.

Alfred Cuschieri at University of Dundee Medical School, and Andrew Riches and Frank Gunn-Moore, both of St. Andrews University, are supporting the research.

For more information, visit: www.dundee.ac.uk