Tiny fluorescent crystals barely visible to the human eye that could revolutionise cancer diagnosis

May 26 2005

Scientists funded by the Association for International Cancer Research have developed tiny fluorescent crystals barely visible to the human eye that could revolutionise cancer diagnosis and treatment in a big way.

In one of the largest international and interdisciplinary collaborations the UK-based charity has funded, researchers from France, Russia and Britain specialising in the highly-complex field of nanotechnology have developed a method of labeling specific molecules within cells using nano-scale marker particles that can be detected by their very strong fluorescence when any light from ultraviolet to red is shone on them.

Already the team are using them to study tissue samples from patients to detect and monitor in real time specific molecules inside cancer cells, made possible because of a series of scientific triumphs not previously achieved.

The first was to work out how to synthesise the nanocrystals in large enough quantities to use them to study biological samples. Next they had to make them soluble in water and the third stage was to develop a coating for the nanocrystals that prevented them from being too toxic to biological material.

Once these hurdles had been overcome, Dr Igor Bronstein of the University of York (currently working at the Institute for Animal Health in Compton, Berkshire) together with Professors Igor Nabiev from Reims, in France and Vladimir Oleinikov from the Russian Academy of Sciences in Moscow used sophisticated methods of protein chemistry to attach nanocrystals to antibodies and used them to identify the molecule p-glycoprotein which is known to make cancer cells resistant to chemotherapy.

Explains Dr Bronstein:"The nanocrystals were so bright that a single molecule of p-glycoprotein on the cell surface could be detected. The challenge then was to optimise the nanocrystals for their direct application to diagnosis by using surgical biopsies. The simultaneous multicolour labeling of different cancer markers was the proof of principle step, showing that nanocrystals could be used with any type of antibody to analyse any type of molecule in cancer cells and tissues more effectively and more accurately than had been possible before".

According to Derek Napier, AICR's Chief Executive, nanotechnology could change the way we approach cancer research. "To understand the rise and progression of cancer we need a long term tracking of cells and molecules. The available existing fluorescent dyes suffer from photodegradation and can't do it. Nanotechnology is removing these obstacles and moreover, these crystals are extremely stable and fluoresce for many days. I believe this important development has opened up a new path towards more effective methods to diagnose and treat cancer in the future".