Diamonds may turn out to be a cancer patient’s best friend, according to scientific research.

Scientists have discovered that microscopic carbon particles called nanodiamonds can combat hard-to-treat drug-resistant cancers.

Nanodiamonds, which measure between two and eight millionths of a millimetre across, bind to chemotherapy drugs.

Researchers found they can be used to deliver powerful agents to cancer sites without damaging surrounding tissue.

In mice with liver and breast cancers, the particles allowed a normally lethal amount of chemotherapy drug to be used with few ill-effects. Tumours were significantly reduced in size and survival rates among the animals increased, the US team reported in the journal Science Translational Medicine.

“Our results show the nanodiamond’s enormous translational potential towards significantly improving the efficacy of drug-resistant cancer treatment and simultaneously improving safety,” said lead researcher Dr Dean Ho, from Northwestern University in Chicago.

Nanodiamonds have unusual properties that allow their surfaces to attach to a wide range of compounds, including those used to fight cancer.