MRI contrast agent could improve cancer diagnosis

Researchers at the University of Pennsylvania’s School of Engineering and Applied Science have designed glycol chitosan-coated iron-oxide nanoparticles that are attracted to the acidic environments in which tumours generally thrive.

Scientists have previously attempted to design targeted contrast agents by coating nanoparticles with proteins that bind only to receptors found on the exterior of tumours. 


’One of the limitations of a receptor-based approach is that you just don’t hit everything,’ said associate professor Andrew Tsourkas. ‘It’s hard to recommend them as a screening tool when you know that the target receptors are only expressed in 30 per cent of tumours.’

The new approach takes advantage of something known as the Warburg effect. Most of the body’s cells are aerobic and primarily get their energy from oxygen. However, even when oxygen is plentiful, cancerous cells use an anaerobic process for their energy, which turns glucose into lactic acid and creates a lower pH than the surrounding healthy tissue.