Painting brain tumors with nanoparticles may help defeat cancer

Nanotechnology is preoccupying science to the point where it's starting to seem unremarkable. But a group of researchers from the University of Washington has released findings that could profoundly improve the chances of surviving brain cancer. The team has developed a fluorescent nanoparticle that is capable of penetrating – for the first time – the blood-brain barrier without damaging it. The fluoro nanoparticle targets tumors using a derivative of scorpion venom and enables precise imaging of the size and location of cancerous growths. When the particles meet the tumor, they light up like Christmas.

Brain cancers are incredibly invasive and, therefore, very hard to completely remove through surgery – it’s difficult for surgeons to know where the brain ends and the tumor starts. The fluorescent nanoparticles not only allow much more accurate imaging but can also be loaded with an infrared dye, enabling the neurosurgeon to literally see the boundary between cancerous and normal tissue.

“Patient survival for brain tumors is directly related to the amount of tumor that you can resect," says Professor Richard Ellenbogen, one of the researchers. "This is the next generation of cancer imaging," he said. "The last generation was CT, this generation was MRI, and this is the next generation of advances."

Even by nanotechnology standards, this nanoparticle is impressive. In order to get past the almost impenetrable blood-brain barrier – which protects the brain from infection – the nanoparticles are about a third of the size of those used in other parts of the body, just 33 nanometers in diameter (33 billionths of a meter). They target tumor cells with chlorotoxin, a peptide (short molecular chain) that comes from scorpion venom and is becoming increasingly popular for its tumor-seeking abilities.

While the nanoparticles have so far only been tested on mice, the research group can already see further applications for human use. Loaded with chlorotoxin, the nanoparticles actually slow tumor growth. And, because they improve the resolution of imaging by ten times or more, they may help in much earlier detection and treatment of tumors.