Kiwi doctor's dots search and destroy cancer cells

Tiny "light" particles that seek out and destroy cancer cells before they grow into tumours have been developed by Wellington scientists.

After nearly six years, Victoria University professor Richard Tilley said researchers had established the tools to detect cancer when it was at the stage of a single diseased cell.

In some cases, MRI scans cannot currently identify tumours until they are about 2.5 centimetres wide.

"This will mean earlier detection, so it could lead to a better chance of survival."

The discovery came after Dr Tilley, a synthetic chemist, found a way to make tiny silicon particles that gave out light and could be sent safely into the body.

The tiny particles, called "quantum dots", are made in beakers and then analysed under a large $1 million electron microscope housed in a room of its own at Victoria University. "It is a monstrous machine to look at atoms," he said.

Although similar particles called quantum dots had been made overseas, they had previously been made only from toxic chemicals.

The research team found a way to bind the quantum dot to a cancerous cell, so a doctor monitoring the dot would find the potential tumour.

The dot could have drugs attached to it, which could treat the cancer in a targeted way, and so reduce the side-effects currently experienced by patients who had chemotherapy.

"With the quantum dots, we would like to target and destroy every single cancer cell."

The technique would be best suited to find skin cancers, and those that are not deep within the body. For those deeper cancers, Dr Tilley had been working on a way to make tumour detection through MRI scans more efficient.

The scans use a contrast agent to show up the difference between diseased and healthy tissue, and the team has created a better contrast agent to improve detection. Working with other experts had made the breakthrough possible, he said.

"As a chemist who just makes materials, you can sit in your office and postulate that these materials will be good for this. It's a real buzz working with them and finding that these particles are better."

The president of the Institute of Chemistry, John Spencer, said the findings had just been accepted for publication in one of the world's most prestigious science publications, the Journal of the American Chemical Society.

That reflected how important the discoveries were, and that Dr Tilley's research was at the forefront of an exciting field.

The results had been achieved by combining the skills of different experts, as Dr Tilley worked with scientists at the Crown research institute Industrial Research Limited, as well as the Malaghan Institute and MacDiarmid Institute research centres, Dr Spencer said.

"What you find is that, by bringing different experts together, you can create something quite wonderful."

- © Fairfax NZ News