Carbon, the building block of every living thing on this planet, may turn out to be the source of a new class of potent drugs that will treat conditions as varied as AIDS, Lou Gehrig's disease, osteoporosis and cancer.
The new drugs are made from buckyballs – a novel form of carbon discovered by Richard Smalley and his colleagues at Rice University in Houston in 1985 – for which he won the Nobel Prize.
Some researchers have compared buckyballs to the discovery of benzene, another carbon molecule, from which 40 percent of today's drugs, such as aspirin and Tagamet, are made.
Buckyballs are inert, nontoxic, and so tiny that they interact easily with cells, proteins and viruses. And they are infinitely modifiable.
In addition, they're hollow inside, so you can put medicines in them.
Smalley, now director of the Center for Nanoscale Science and Technology at Rice, named them after Buckminster Fuller's geodesic dome because they have the same shape.
Extraordinarily tiny – only a nanometer long, which is one-millionth the diameter of a human hair – these balls of carbon are perfectly smooth and round. They spin at over one hundred million times per second, and can withstand slamming into a stainless steel plate at 15,000 mph, merely bouncing back unharmed.
Buckies have since spawned a cornucopia of similar shapes known as fullerenes, so versatile that the "buckyball is a sort of Rosetta Stone of what we now realize is an infinity of new structures made of carbon," Smalley said.
They have been fashioned into tubes that may someday serve as superconductors. But their most important application may turn out to be in medicine.
"We liken buckyballs to a molecular pincushion," said Uri Sagman, a former oncologist who founded C Sixty, a company developing the product. "You can decorate this thing with other chemicals to whatever extent you want."
The first bucky drug may be available as soon as 18 months from now and will target the AIDS virus. C Sixty, of Toronto, Ontario, is applying to the FDA for Phase I testing and fast-track status on a novel fullerene drug for HIV that has shown great promise in animal studies, even against drug-resistant forms of the virus.
The drug targets the HIV protease, and because of its size, shape and chemical qualities, it easily fits into a pocket on the virus that disrupts its ability to reproduce.
Even better, it seems nontoxic. "The lethal dose in animals is astronomical," Sagman said. "And it is absorbed well orally and excreted unaltered by the kidneys, so it doesn't harm target organs. That's important because compliance is a big problem with AIDS drugs, since patients find them too toxic."
The second fullerene drug, which the company hopes to put into clinical trials, fights Lou Gehrig's disease. If successful, it may treat similar illnesses such Parkinson's disease. Animal studies are encouraging.
"We think it works as an extremely potent free-radical scavenger," said Steve Wilson, professor of chemistry at New York University and a consultant to C Sixty. In many motor neuron diseases, damage is done by free radicals, which eventually induce nerve cells to commit suicide.
Osteoporosis and diagnostic imaging are two potential career tracks for Bucky.
Lon Wilson, professor of chemistry at Rice University and a C Sixty consultant, is working on fitting radioactive models inside the ball, as if it were a molecular spaceship.
He hopes that as buckies travel through the bloodstream, they will emit radiation. But since they are excreted intact, they will completely remove the radiation from the body after the procedure.
"If you can hide radiation toxicity in a carbon shell and get it to clear from the body, you've really got something," Wilson said.
He is also working on fullerenes that will deliver bone-building drugs for osteoporosis. Currently, most of those drugs are not well absorbed and are toxic. Buckyballs might offer a nontoxic molecular ship to deliver the materials safely to fragile bones.
And on a more distant horizon, buckies may someday carry light-activated and/or cancer-killing drugs to tumor cells. Smalley would love to see this last application happen soon. The discoverer of buckyballs has recently suffered a recurrence of lymphatic cancer.
At first, his cancer was put in remission with traditional chemotherapy. When it came back, he received state-of-the-art monoclonal antibody therapy. If it recurs a third time, he figures, buckyballs with cancer-killing antibodies and chemicals riding atop their domes just might save his life.
Whatever the timeline of the new medicines, the future of buckies looks bright.
"Buckyballs will undoubtedly become an important part of the total pharmaceutical toolkit over the next few years," said Robert A. Freitas, Jr., research scientist at Zyvex Corporation, a nanotechnology firm. "They will help save or improve the lives of millions of people around the world."