GEOFFREY VON MALTZAHN: The 28-year-old PhD candidate has won this year's $30,000 Lemelson–M.I.T. Student Prize for his work developing ways to use nanotechnology to fight cancer. Image: COURTESY OF HARVARD-MIT DIVISION OF HEALTH SCIENCES AND TECHNOLOGY
The Harvard–M.I.T. Division of Health Sciences and Technology (HST) today named Geoffrey von Maltzahn this year's recipient of the $30,000 Lemelson–M.I.T. Student Prize for developing a technique that utilizes nanosize gold particles to target malignant tumors and kill cancer cells but spares healthy tissue. Established in 1994, the award is given out annually to a Massachusetts Institute of Technology senior or graduate student who has contributed significantly to the fields of science or technology.
The approach capitalizes on "tumors behaving like tumors," says von Maltzahn, a 28-year-old PhD candidate, which means malignancies trigger the growth of as many new blood vessels as quickly as possible to nourish and make them thrive. But instead of feeding these tumors, von Maltzahn relies on these ultra-porous nascent blood vessels to transport rod-shaped gold nanoparticles (injected into cancer patients) inside tumors, where they latch onto malignant tissue.
Although other researchers have tested the use of nanoparticles to fight cancer (read about another M.I.T.–Harvard effort here), von Maltzahn has developed two ways to attack tumors once the nanoparticles have set up shop there. The first is to shine a near-infrared laser on the patient's skin above the malignancies; the light heats the gold enough to interrupt and destroy cancer cells with minimal, if any, damage to surrounding healthy cells. In preclinical mouse trials a single nanoparticle injection (which includes trillions of nanoparticles) eradicated 100 percent of tumors when combined with near-infrared light. The problem with current radiation therapy is that in most cases it is not confined to malignant growths and healthy tissue gets caught in the crossfire, according to von Maltzahn.
His other award-winning technique involves two injections: The first batch are sent out as scouts to identify and attach to tumors. Once in place, they serve as markers for a second battalion of nanoparticles that are covered with cancer-fighting agents, which home in on and destroy the tumors but leave healthy tissue unscathed. In mouse trials, von Maltzahn and his colleagues found that this "scout–assassin" system successfully delivered doses of medicine in mice that were more than 40-times more potent and much more successful at killing tumors than were injected medicine-coated particles sans the ability to communicate with nanoparticle advance teams.
The major benefit of both von Maltzahn's methods is that the medication could be injected anywhere in the body but would only latch onto the cancerous tissue. "If we were injecting this directly into the tumor, it wouldn't be a transformative technology," he says. "It's essential to be able to inject it intravenously anywhere in the body and have it … home in on the tumor." Once the medicine has been delivered, the nanoparticles would be stripped bare and could safely pass out of the body after being filtered from the blood by the spleen or liver, von Maltzahn says, noting that gold has a very low toxicity profile.