Combination of Nanoparticles Creates a More Powerful Cancer Targeting Tool

A collaborative effort of scientific institutions in California and Massachusetts has created a multi-prong tumor killing technology that uses two types of nanoparticles injected into the blood stream that cooperate to target and destroy tumors. The study, just published in the Proceedings of the National Academy of Sciences, describes how the nano brew was successfully applied to mice with epithelial tumors.

The first particle is a gold nanorod “activator’ that accumulates in tumors by seeping through its leaky blood vessels. The gold particles cover the whole tumor and behave like an antenna by absorbing otherwise benign infrared laser irradiation, which then heats up the tumor.
After the nanorods had circulated in the bloodstream of mice that had epithelial tumors for three days, the researchers used a weak laser beam to heat the rods that attached to the tumors. This sensitized the tumors, and the researchers then sent in a second nanoparticle type, composed of either iron oxide nanoworms or doxorubicin-loaded liposomes. This “responder” nanoparticle was coated with a special targeting molecule specific for the heat-treated tumor.
The researchers designed one type of responder particle with strings of iron oxide, which they called “nanoworms,” that show up brightly in a medical magnetic resonance imaging, or MRI, system. The second type is a hollow nanoparticle loaded with the anti-cancer drug doxorubicin. With the drug-loaded responder, the scientists demonstrated in their experiments that a tumor growing in a mouse can be arrested and then shrunk.

Images: Top: Gold nanorods accumulate in tumors. Bottom: Doxorubicin-loaded liposomes are designed to kill tumors.
UCSD press statement: Researchers Develop “Nano Cocktail” to Target and Kill Tumors…
Abstract in PNAS: Cooperative nanomaterial system to sensitize, target, and treat tumors