Could Tiny Diamonds Help Beat Cancer?

By PAT HAGAN

DIAMONDS too small to be seen by the naked eye are being tested as a new treatment for cancer.

Scientists in America have discovered that by coating so-called nanodiamonds with chemotherapy drugs, and then arranging the diamonds into clusters, they can deliver more cancer-busting medicine to the heart of a tumour.

Tests show the diamond clusters protect healthy cells from their toxic cargo, only releasing the drugs when they break up inside the cancerous growth. The diamonds are flushed out of the body in waste products produced by the liver and kidneys.

The breakthrough, by researchers at Northwestern University in Chicago, marks the latest development in the use of nanomedicine to combat cancer.

Teams of experts around the world are studying the potential for ways of smuggling more chemotherapy medicine into tumours and stopping it from damaging healthy cells.

Their search has led to them testing everything from microbubbles made from fat to particles of gold dust as potential carriers of drugs.

The incentive is to find a way of reducing some of the more unpleasant side-effects suffered by cancer patients undergoing chemotherapy.

Cancer affects an estimated one in three people in Britain at some point in their lives. Many end up needing chemotherapy, which can cause hair loss, nausea and increased risk from everyday infections because the toxic drugs suppress the immune system.

This happens because chemotherapy drugs injected into the body attack healthy as well as cancerous tissues. Scientists hope the nano- diamonds will slash the amount of toxic medicine affecting the body by delivering more to the tumour.

Each diamond is thousands of times smaller than a human hair.

Several hundred thousand of them would fit on a pin head. Scientists began by coating part of the surface of each nanodiamond with a widely used chemotherapy drug called doxorubicin hydrochloride.

This drug is often used to treat advanced ovarian cancer and is normally contained within globules of fat injected into the bloodstream. The diamonds were formed into clusters, each one made up of 25 to 50 diamonds, with the chemotherapycoated surfaces mostly on the inside.

Tests showed the clusters passed by healthy cells without harming them.

Once inside the tumour, they gradually broke up and released the active medicine inside. Even assembled as clusters, they are still small enough to penetrate the wall of a cancer cell.

Each one is still about 100 times smaller than the fat bubbles already used, making it easier for them to get inside malignant cells. Scientists have also found the diamond clusters can carry five times more medicine than other nanoparticles, such as fat bubbles. This is because the clusters are made up of irregular- shaped diamonds that have a much greater surface area than a simple bubble.

Another major advantage is diamonds do not cause healthy cells to react and become inflamed, a common reaction to foreign substances.

Such inflammation can even reduce the activity of the cancer medicine.

Dr Eric Pierstorff, who took part in the latest study, said: ‘The nanodiamond cluster provides a powerful release in a localised place effective but less toxic.’ The diamond therapy is still being tested in animals and is unlikely to be used in humans until large-scale trials have been conducted.

Cancer Research UK welcomed the diamond study, but stressed the treatment is not yet available for patients. A spokesman said: ‘It’s important to find ways of sending cancer drugs straight to tumours, so they don’t damage healthy cells. But these nanodiamonds were only tested in cells grown in the lab.

‘These early studies suggest that nanodiamonds could help to target drugs directly to tumours. But we are a long way from seeing them being used to treat patients.’

(c) 2007 Daily Mail; London (UK). Provided by ProQuest Information and Learning. All rights Reserved.