London: Scientists at a UK university have discovered that adding nanoparticles of gold can boost the potency of a cancer drug by 50 per cent.

This allows more malignant cells to be killed while healthy tissue is left unharmed without giving harmful amounts of the drug. The aim is to develop an alternative to chemotherapy which cannot differentiate between healthy and unhealthy cells and acts like a poison on the body in general.

But newer cancer drugs, such as Glivec, which is used for leukaemia, or Sutent, launched last month to tackle kidney and rare digestive tumours, do not affect healthy cells.

Glivec, for example, acts on the enzymes which control the growth of certain cancers.

The study, by the University of East Anglia, used a light sensitive drug to target cancer cells.

The drug homes in on the tumour and, when exposed to light, it starts to produce a form of ‘active’ oxygen toxic to cancer cells. Dr David Russell and his team wanted to see if there was any way of making the system, which is known as photo- dynamic therapy, more efficient.

They attached gold nanoparticles to the drug and used it on cervical cancer cells in the laboratory, according to a report in the Royal Society of Chemistry journal called Photochemical and Photobiological Sciences.

It emerged that adding gold made the reaction stronger, causing 50 per cent more active oxygen, known as ‘singlet oxygen’, to be produced. And it was this that led to more cancerous cells taking up the drug and dying off. The researchers said their results were ‘very encouraging’ and are planning further clinical trials.

The scientists plan work with Italian scientists to replicate the laboratory results in animals.

Because the research is still at a very early stage, it is likely to be several years before the drug will be tested on humans. But Professor David Philips, an expert in photo- dynamic therapy from Imperial College London, said the results bode well for future studies.