When it comes to brain surgery, Stanford researcher Sam Gambhir, M.D., Ph.D., believes his team has an idea that's pure gold.
"These particles are so precise in finding tumors from the models that we've tested so far, that a surgeon's scalpel wouldn't be able to be as precise," Gambhir said.
The tiny particles he's referring to are actual gold.
To understand their value, it helps to shed some light on the cutting edge of brain surgery. In 2010, surgeons at UCSF were using a special dye that migrates into tumor cells. When doctors shined laser light on the tumor, the cancerous cells glowed orange, making them much easier to find.
Gambhir believes his gold nanoparticles can produce even more precise images in a unique way.
"The light that we use is used to excite particles that we have that are made out of gold and as they get excited they produce sound," Gambhir said. "So that's why this is called photo-acoustic imaging, in that the light is used to actually make sound."
The product is 3D images, similar to the latest generation of ultrasounds.
Gambhir says the gold nanoparticles circulate through the bloodstream, but ultimately leak out of the more porous blood vessels that feed tumors. Once outside, the particles lodge in the tumor tissue, becoming visible.
"Our particles are shown in red, and you can see they perfectly outline the tumor and don't show up in the areas without tumor. That's the border of the tumor," Gambhir said.
He says the particles can also be seen by an MRI and a third technique called Raman imaging. He says the images produced in animal models are so precise, surgeons could follow the tentacles of difficult tumors such as glyoma, which extend in to healthy brain tissue.
"Because you don't want to remove too much normal brain. It becomes very important in that case to only remove the tumor and nothing but the tumor," Gambhir said.
He says the team is now working towards safety data to support eventual human trials, with the goal of creating a new gold standard for brain surgery.
Gambhir believes the gold particles could ultimately be used not just to photograph tumors, but potentially to kill them as well.
Written and produced by Tim Didion