Inveterate Inventor

Lemelson-MIT Student Prize winner improves cancer therapies with nanotech

At the age of eight, Geoffrey von Maltzahn '03 made his debut as an inventor by designing a pulley system to switch his room light on and off from his bed. Before long, he'd extended the system to control his alarm clock and stereo. Now a PhD candidate in the Harvard-MIT Division of Health Sciences and Technology, he's filed eight patent applications. And in March, he won the $30,000 Lemelson-MIT Student Prize for developing novel cancer treatments based on nanotechnology.

Credit: Mark Ostow

Von Maltzahn has been working with his thesis advisor, Professor Sangeeta Bhatia, to find ways to deliver cancer therapies without affecting healthy tissues. Today, less than 1 percent of chemotherapy drugs end up in the tumors they're intended to eradicate; the rest go elsewhere in the body, causing harmful side effects. So far, he's come up with two promising approaches.

One is a type of highly conductive gold nanoantenna that can be injected intravenously to target tumors and convert infrared light into heat, improving the precision of cancer ablation therapies. The antennas are coated with a polymer that keeps them from being taken up by the immune system, enabling them to circulate through the bloodstream until they pass through the pores of tumor blood vessels and get trapped inside. When von Maltzahn injected nanoantennas into cancerous mice and exposed them to near-infrared light, the antennas concentrated the light's energy in the tumors, precisely heating them to 70 °C. A single treatment using harmless levels of near-infrared light destroyed all the tumors within 15 days.

The body's own repair system inspired von Maltzahn's second cancer innovation. Here, the nanoantennas that he developed serve as "scout" particles, which locate a tumor; once inside, they send out signals to attract "assassin" nanoparticles, which arrive bearing drugs. The scouts' secret is to convert infrared light into just enough heat to cause a localized blood vessel injury, setting off the natural coagulation process. It's like sending up a flare that makes the tumor easier for the assassins to find, von Maltzahn says. In preclinical trials in mice, scout and assassin nanoparticles significantly outperformed noncommunicating nanoparticles, delivering more than 40 times more of the therapeutics to tumors.

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Von Maltzahn's other inventions include a low-cost method for hemorrhage detection, a new class of self-assembling peptides with promising applications in gene therapy, and a method for remotely controlling the release of drugs from nanoparticles. In addition to working on his PhD and collaborating on 19 papers, he has mentored 14 undergraduates in the lab. His own UROP experiences opened doors for him, so he's eager to return the favor--and to tap into undergrads' brain power. "They think about things very differently depending on their focus," he says.

At 28, von Maltzahn has already founded two companies: Nanopartz, which supplies gold nanoparticles for research and commercial applications, and Resonance Therapeutics, which is developing clinical applications for nano rods and technologies to improve the efficacy of cancer therapeutics. "In some ways the most important part of the process is making sure [an invention] gets to patients," he says. But he plans to continue inventing: after defending his thesis, he wants to start thinking about sustainable energy and other environmental issues. "What really gets me out of bed in the morning is thinking about the next big problem," he says.