More than 50 years ago, at a meeting of the American Physical Society hosted by Caltech, Richard Feynman gave a talk called "There's Plenty of Room at the Bottom." In his visionary speech, Feynman discussed the technological promise of tiny machines as small as a few atoms. This promise has grown into a full-fledged discipline we now know as nanoscience, and it is the subject of TEDxCaltech's last session, "Nanoscience and Future Biology."
Mark Davis, a chemical engineer at Caltech, will discuss his efforts to design nanoparticles to battle cancer. After seeing his wife suffer through aggressive chemotherapy in 1995, Davis set out to find a cancer treatment that would avoid the harmful side effects that are often as damaging as the disease itself. Over the last 15 years, Davis and his colleagues have designed nanoparticles—tiny spheres about 30 to 70 nanometers in diameter—that target tumors and deliver cancer-killing agents. Unlike the materials used in traditional therapies that involve tiny molecules, these nanoparticles are too big to penetrate other body tissues, thereby avoiding many harmful side effects. At the same time, they're just the right size to find their way to cancer cells.
Recently, Davis and his colleagues have packed double-stranded RNA, a molecule similar to DNA, into nanoparticles. Through a process called RNA interference, for which the 2006 Nobel Prize in Physiology or Medicine was awarded, the double-stranded RNA is able to silence particular genes and prevent them from functioning. By silencing the specific genes responsible for particular cancers, this technique would be a powerful way to combat cancer at the genetic level—a method that avoids the complications and potential side effects of therapies that focus on individual proteins.
The researchers engineered the nanoparticles so that after the particles make their deliveries, they fall apart and leave the body via urine. In the last year, Davis and his team have shown, for the first time, that this technique works in cancer patients. "It's a clear example of nanotechnology enabling new biotechnology for therapeutic use in humans," Davis says. He envisions that cancer treatment in the future will be not only personalized but dynamic. If the cancer mutates, doctors can simply change the genetic target of the nanoparticles accordingly.
While the potential of minuscule machines are enormous, individual nanodevices are just the beginning, says Caltech physicist Michael Roukes. In his talk, titled "Embracing Biocomplexity: Plenty of Room in the Middle," Roukes will outline the importance of moving up from the scale of individual nanodevices and molecules to groups and large collections of cells. Currently, we only understand biological systems to an approximate degree, he says. We know how cells, molecules, or proteins behave or interact as groups, but we don't know how each molecule contributes to the function of the whole biological system.
The goal, he says, is to be able to understand, engineer, and manipulate biological circuits—the complex interactions among genes, proteins, and their larger functions—the same way we can design, build, and control computer circuits. Computer engineers talk about "flops," short for floating-point operations per second, a measure of computing power in terms of individual calculations down to the bit level. Roukes predicts that in 50 years, we will arrive at the same level of mastery with biology, speaking in terms of what he calls "bops," biological operations per second. "This will pave the way for future medicine that's very personal to our genomic uniqueness and our environmental history," he says. "It will allow us to understand current physiological conditions and be able to make very detailed preventative predictions about what's needed in order to keep people in good health."
TEDxCaltech happens tomorrow. Visit http://tedxcaltech.com to watch the talks live.
