a gear head goes bio
stories by Neil Caudle
Arming particles for precision strikes against cancer.
His was not the usual path to a job fighting cancer. Stephen Foulger was a California dude, a surfer and gear head who built motorcycles. He went to college at Santa Barbara to surf, studied English (it bored him), worked in a machine shop, and wandered into engineering (it didn’t bore him). That led to MIT for grad school, polymer physics, and an R&D job with Pirelli, the Italian tire maker and European leader in fiber optics. He came to Clemson because his wife was disinclined to pack two babies off to Italy.
The story of Foulger’s improbable ride from motorcycle mechanics to optics to cancer research is, in some ways, a fable for how science works these days. Say goodbye to pigeonholed specialists laboring in isolation. Solving big problems in science generally requires teams with many working parts. And, as any good surfer knows, you can’t ride the same wave forever. Why would you want to? The wave Foulger rides at the moment pushes his limits.
For one thing, he has to learn the alien nomenclature of cancer genetics. And while he’s a darn good mechanic when it comes to tuning up a polymer, his new line of work involves human biology. Don’t tell the bio guys, but Foulger wraps his head around proteins by thinking of them as polymers, which oversimplifies but captures the gist: Polymers and proteins are both large molecules whose parts are connected by chemical bonds. As medical science drills down to the fundamental business of human cells, what it finds is a lot of basic physics, chemistry, and math. And that’s the common ground on which Foulger meets people like Michael Sehorn, his collaborator from genetics and biochemistry at Clemson.
With help from Sehorn and others, Foulger figures out how to arm nanoparticles for seek-and-destroy missions deep inside the human body. He is concocting stealthy particles that can elude the body’s efforts to expel them, so they can roam around long enough to connect with receptors or proteins common in cancer cells. With his knowledge of optics and chromophores (the parts of molecules responsible for color), Foulger can equip those particles to find their targets and switch on a tiny, biochemical light that means cancer.
“Take pancreatic cancer, for instance,” Foulger says. “If you don’t catch it right away, it has a huge death rate. So if you could do periodic imaging of the body, and you could see small speckles of light around the pancreas, you’d say, okay, this person has cancer. That’s the approach we’re taking.”
Meanwhile, he’s working on survivin. It sounds like the title for a Grateful Dead song, but survivin is actually the name of a protein that helps keep cancer cells alive by defeating the normal process of apoptosis, which tells cells when to die. Stop survivin, and chemotherapy drugs will work better. And if you can deliver those drugs directly to the cancer by loading them onto particles, you’ll have a lot less collateral damage, because the drugs won’t slaughter the good cells along with the bad.
“Chemotherapy is a brutal, medieval way of killing something,” Foulger says. “It basically just kills cells. And cancer cells have developed ways to prevent that. So if you get a chemotherapy drug that starts killing the cells, anti-apoptosis proteins like survivin can go in there and actually undo or slow the damage to the cell you’ve tried to kill with the drug. The idea is to make a particle that binds up survivin and then releases a chemotherapy drug. You’d get a synergy going on that would be really effective when it comes to killing cancer cells.”
Foulger came to cancer research via work on colloids, substances microscopically dispersed in other substances (acrylic polymers in paint are one example). Because some kinds of colloids showed promise in imaging systems for cancer detection, the National Institutes of Health began asking Foulger to review medical research involving colloids. In the process, he realized that his work with chromophores could have an anti-cancer application—for both diagnosis and treatment.
“So I thought, okay, I’ll give it a whirl,” he says. And he did.
Stephen Foulger is the Gregg-Graniteville Endowed Chair and Professor of Materials Science and Engineering in the College of Engineering and Science. Funding for his work is primarily from the Defense Advanced Research Projects Agency (DARPA) and the National Science Foundation. Michael Sehorn is an assistant professor of genetics and biochemistry in the College of Agriculture, Forestry, and Life Sciences.