Nano-diagnosis

Specially designed nanoparticles can reveal tiny cancerous tumours that are invisible by ordinary means of detection, according to a study by researchers at

in St. Louis.

The researchers demonstrated that very small human melanoma tumours growing in mice, which are indiscernible from the surrounding tissue by direct MRI scan, could be "lit up" and easily located as soon as 30 minutes after the mice were injected with the nanoparticles.

Because nanoparticles can be engineered to carry a variety of substances, they also may be able to deliver cancer-fighting drugs to malignant tumours as effectively as they carry the imaging materials that spotlight cancerous growth.

"One of the best advantages of the particles is that we designed them to detect tumours using the same MRI equipment that is in standard use for heart or brain scans," says senior author Gregory Lanza, M.D., Ph.D., associate professor of medicine. "We believe the technology is very close to being useful in a hospital setting."