Medicines from Space : Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

Benefits Begin

When will space medical technologies start reaching patients on Earth? Some already have.

One NASA spinoff comes from work on the motion sickness astronauts experience. Drug injections are impractical, since the medications may froth under weightlessness. Vomiting can make the use of oral medications also unworkable. Drug administration through a patch placed on the skin provided the answer for space voyages. Now the drug scopolamine is approved in transdermal patch dosage (Transderm Scop) to relieve motion sickness on Earth. Similar delivery systems with the ability to deliver steady concentrations work in nicotine patches, helping smokers to kick the tobacco habit, and in nitroglycerin patches relieving angina pectoris (chest pain).

Wireless telemetry NASA developed to communicate with its space vehicles in orbit now monitors patients in hospital coronary care units. Programmable implantable medication systems designed for astronauts later went into clinical trials, and companies are investigating such a pump to deliver precise, preprogrammed concentrations of insulin to diabetics over a long period.

The work goes on. One important field is bioproducts bioprocessing, or use of the microgravity environment to form and manipulate biological materials. Macromolecules used for artificial tendons, blood vessels, and even corneas are among potential products.

Investigation continues, exploring whether certain products could be cheaper, faster and easier to produce or of greater purity when produced in space. These include: pancreatic beta cells capable of curing juvenile diabetes patients in a single injection; an interferon to give resistance to viral infections and possibly to treat some cancers; and epidermal growth factor to stimulate healing of burn victims' skin. In addition, as many as 50 approved products seem candidates for superior production in space. The confines of a spacecraft don't allow much experimental equipment. Worthy medical experiments of different kinds have to compete with one another for inclusion on each flight, in addition to competing with those of other scientific disciplines. Juries of NASA scientists rank proposed experiments by their promise and significance.

It is too early to declare with certainty what FDA's policy will be toward any future consumer products or technologies produced in, or unique to, orbiting pharmaceutical plants. The last time FDA confronted a novel means of production, in the products of the new biotechnology appearing during the last decade, the agency decided to judge the safety and efficacy of all products equally, regardless of their means of production. Whether any visionary space-made "wonder drugs" will present unique issues requiring a different approach, only time will tell.

FDA Experiment Aboard Discovery

Mary Ann Principato, Ph.D., of FDA's Center for Food Safety and Applied Nutrition sent cell cultures from her FDA lab aboard the space shuttle Discovery in 1993.

"I'm used to coaxing these cultures along," says Principato, an immunologist with the center's division of virulence assessment. "But to have something shot up at forces greater than any centrifuge spin, well, I just hoped and prayed that I'd get something back to work with."

Her experiment was sent on the shuttle to find out how T-cells from mouse bone marrow respond to the bacteria staphylococcal enterotoxin B in zero gravity. On Earth, the first time T-cells meet staphylococcal enterotoxin B they proliferate. But scientists had questions about whether bacteria or their products activate T-cells in space. Principato's experiment suggests they do.

Principato set up bone marrow feeder cultures and scaled down the experiment from "Earth size" culture dishes to a miniature size that would fit in the tiny wells allotted to her in the specially designed mini-lab.

Principato decided that, even though NASA didn't require it, she wanted to set up the experiment at Cape Canaveral herself. She drove for 14 straight hours on April 3 to get to Cape Canaveral by the newly scheduled launch date. She set up her experiment on Sunday, and Monday was a whirlwind of press briefings and VIP tours. "I was running nonstop, but I never felt tired," she says. She was in the viewing stands as the countdown began, shortly after 1 a.m. on April 6.

T minus 13. T minus 12. When the launch stopped at T minus 11, "my heart sank down into my feet," says Principato. "Then panic ensued because my T-cells were locked up in the shuttle."

It turned out that a bad computer circuit had indicated an unclosed fuel vent valve when the valve had, in fact, closed.

Principato was allowed to check her cells and found they were still alive. She gave them back to the shuttle technicians and crossed her fingers.

The launch was rescheduled for early morning April 8. When the countdown reached T minus 10, "there was a loud cheer," she says.

Discovery lifted off at 1:29 a.m. "It was a glorious sight to see the shuttle go up," she recalls. "It was a moment I'll never forget."

Later that morning, she was able to listen in on the control room's radio as the astronauts worked. She wanted to be sure that they had "thrown the switch" that would turn on the machinery and mix the staphylococcal enterotoxin B with the T-cells.

"You think you've come up with the perfect answer to all problems and then have to hope that a fuse doesn't blow or something doesn't overheat."

John E. Vanderveen, Ph.D., director of FDA's Office of Plant and Dairy Foods and Beverages (which contains the division in which Principato works), says that, "It's always important for government agencies to cooperate, especially when resources are limited. The unique techniques that were employed may be valuable to us in the future."

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.