Scientists aglow over drug for radiation poisoning
With the Starship Enterprise seemingly doomed after losing warp power, Mr. Spock exposes himself to lethal radiation in Star Trek II: The Wrath of Khan. After repairing the engines and saving the day, Spock dies.
Evidently, the movie's writers didn't think scientists would find a drug to cure radiation poisoning by the late 23rd century.
Yet local scientists may be on the verge of doing just that more than two centuries before the setting of the Star Trek film.
Rice University's Jim Tour and his colleagues at two Houston health institutions have found a drug that, when given to mice before radiation exposure, is 5,000 times more effective than the best-available therapy for radiation injuries.
Officials at the Department of Defense, seeking remedies for the radiation sickness that would follow a nuclear strike, were so taken by the research that they recently gave Tour a $540,000 grant and asked him to compress the next phase of testing into an almost unheard-of nine months.
In that time, Tour's research group hopes to improve the drug so it works as well when given after radiation exposure as it does before.
"They originally asked for something in six months, but I told them that was impossible," said Tour, a chemist who directs Rice's Carbon Nanotechnology Laboratory.
Radiation disrupts cells by freeing molecules from their chemical bonds and allowing them to run amok inside the nucleus.
These so-called free radicals can destroy a cell's DNA, killing the cell or preventing it from dividing. The result can be a slow death of the victim as organs fail.
To address the problem, Tour and his partners at two University of Texas institutions - the M.D. Anderson Cancer Center and the Health Science Center - have created a drug that's deceptively simple.
Just like Wonder BreadThey started with two common food preservatives - the same stuff, BHA and BHT, that keeps Wonder Bread fresh for weeks - as a means to carry away free radicals before they can cause harm.
But for the food preservatives to become effective, the scientists needed a way to get them inside cells.
That's where carbon nanotubes, single layers of carbon atoms curved into tiny cylinders, came in handy. The research team attached the food preservatives to the nanotubes, which, because of their size, provided a perfect vehicle for traversing the body's arteries and entering cells.
Tour said he began his research with the goal of finding a drug to protect astronauts on long-duration space missions from the radiation to which they are exposed outside Earth's atmosphere.
But the test results in mice, which were given the drug 30 minutes before a blast of radiation, were so impressive that Tour thought the drug might have much broader potential.
A long searchTour - who serves on the Department of Defense's Science Board, a technical advisory group for the Pentagon - was put in contact with top officials at the Defense Advanced Research Projects Agency, which funds proposals that promise high rewards but often have little chance of success.
Results in mice don't always translate into results in humans, or course. And DARPA wants a drug that can be effective even if given 12 hours after exposure to radiation.
Need for such a drug is great, said Robert Emery, a radiation safety expert at the UT Health Science Center.
About half the deaths from a large nuclear blast would result from the initial explosion. Radiation medication, he said, would benefit the remaining victims in a fallout zone and could prove invaluable to first responders.
Such a drug, experts note, could also help cancer patients recover from radiation therapy.
But, as is true with many new technologies, an anti-radiation drug could have a potential offensive use. Foreign forces, for instance, could set off a nuclear detonation, then take the drug to protect themselves before invading.
Until now, the search for drugs to treat radiation sickness has been so fruitless that it seemed plausible a cure might elude physicians in the day of fictional Star Trek Capt. James T. Kirk.
After World War II, scientists tested thousands of chemicals at Walter Reed Army Medical Center for potential use in radiation therapy, said Dr. Luka Milas, an M.D. Anderson professor of experimental radiology who has worked for decades on the problem of curbing radiation sickness. Only one drug - WR-2721, or amifostine - showed any promise.
Now, Milas, who is working with Tour, has helped discover the drug that is 5,000 times more effective in mice.
"It's incredibly exciting," he said of the latest research. "If we succeed, there is such a huge reward. There are so many potentially positive ramifications of this work."
Milas' group has ideas for taking a drug that worked in mice before radiation exposure and turning it into something that's effective after an event. His lab plans to add other chemicals to the carbon nanotubes that will, in addition to scrubbing up free radicals, speed cellular repair and stimulate the growth of new, healthy cells.
More work to be doneAlready the work is showing promise. At the UT Health Science Center, scientist Jay Conyers has tested newer versions of the original drug and has had some success in treating zebra fish 30 minutes after exposure to high doses of radiation.
Still, Tour said, a viable radiation drug for humans remains "very, very far" away.
The research team must find a drug that's effective post-exposure in mammals larger than mice. Typically, such a drug would take 12 to 14 years of development before coming to market at a cost of $1 billion or so.
Tour conceded, however, that there are special circumstances surrounding the radiation drug that could accelerate its development.
"There is no alternative therapy, and the poor soul so exposed has no hope other than petitions to God," Tour said.
"And that's what drives me," he said, "the hope of saving 1 million people."