According Catherine Murphy, a chemistry professor at the University of South Carolina, Columbia, the shape of a metal determines how much light it absorbs. "If you want to shine near-infrared light—which is really good for tissue penetration—and burn something up," she says, "a rod shape works really well." Murphy developed the process for transforming spherical bits of gold into the nanorods that von Maltzahn used in his research.
Von Maltzahn, who has worked with his advisor Sangeeta Bhatia, a Harvard–M.I.T. HST electrical engineering and computer science professor, on this research for the past five years, is co-founder of a pair of companies that he hopes will help commercialize his technique: In July 2007, he helped form Salt Lake City–based Nanopartz, Inc., a worldwide supplier of gold nanoparticles; in September 2008, he helped create a Boston firm, Resonance Therapeutics, which will further develop his cancer-fighting techniques. Eugene Zubarev, an assistant chemistry professor at Rice University in Houston, developed the method for mass producing nanoparticles that Nanopartz relies on to make its nano products.
Von Maltzahn two years ago developed another nanotech-based approach to stopping cancer that relied on polymer-coated iron oxide nanoparticles bound by DNA tethers, which together helped create a visual image of a tumor through magnetic resonance imaging (MRI), as Scientific American.com reported in November 2007. To test the particles, he and his team implanted mice with a tumorlike gel saturated with nanoparticles and placed the animals into the wells of cup-shaped electrical coils, which activated the nanoparticles via magnetic pulses.
Von Maltzahn says he is currently conducting clinical trials of his near-infrared laser technology (to ablate cancerous tumors), but it is still years away from becoming a routine treatment. The scout–assassin model is even farther from becoming a cancer-fighting staple, says Maltzahn, noting that it could take him and his colleagues another two decades to make it safe and effective enough to use in humans.
Von Maltzahn plans to keep close tabs on his companies while he continues to pursue an academic career as a professor of biomedical or chemical engineering. Neither the business nor the academic aspects of research can be overlooked if medicine is to make its way from the lab to the patient, he says. "One of the things that appeals to me," von Maltzahn says, "is developing therapeutics such as these in a way that they can be commercialized."