New Contrast Agents on the Nanoscale

Use of these new agents may improve the diagnosis and treatment of cancer, according to Kenneth Watkin, a professor in the department of speech and hearing science based at the University of Illinois at Urbana-Champaign.

"The goal of this work for me was to be able to create advanced methods for the treatment of disease, specifically cancer, that reduce the toxic effects that we see with our current treatments," Watkin said. "And to do that, I had to develop really, really, really small carriers. The tiny carriers Watkin and colleagues are proposing would zero in on tumours in much the same way that smart bombs take aim at strategic targets.

In their work with gadolinium oxide nanoparticles, Watkin and McDonald started by breaking nanoparticles down into even smaller particles. Next, they successfully coated the particles with dextran, a naturally occurring carbohydrate. The chemical coating prevents the nanoparticle from undergoing a chemical reaction when it comes in contact with water. It also keeps the nanoparticles from clumping and behaving erratically.

Watkin said gadolinium oxide is a superb imaging agent because of its superparamagnetic properties - "meaning that they work well within a magnetic resonance imaging machine." Its properties as an effective emitter of radiation sources also make it well-suited for use with a type of cancer therapy called neutron capture therapy.

“These little particles capture the neutrons and emit alpha and gamma rays, and that energy - sent out from an accelerator - is what can be used to kill cancer cells”, said Watkins. "These little gadolinium particles capture neutrons at four times a greater rate than boron, and yet boron is what is currently used for neutron capture. This means gadolinium oxide is potentially a multimodal agent" … in other words, a contrast agent that would work with a number of different medical imaging techniques.; Source: University of Illinois at Urbana-Champaign