Adding Sugar To The Wound?
August 22, 2004
Joy Powell, Star Tribune

For thousands of years, the resurrection plant has mystified people by surviving for long periods without water, curling into a brown ball tossed on desert winds, until a dose of rain leads it to burst into lush green.

The mystery of the plant -- and of hundreds of tiny critters that defy death in extreme weather conditions -- has led scientists to a sugar molecule that's being used not only to deep-freeze fish and moisturize skin but, now, to freeze-dry blood cells.

The discovery is expected to change the way the world stores blood human blood and treats trauma victims, experts say.

Cargill Inc. of Minnetonka and a Japanese pharmaceutical firm, Hayashibara Co. Ltd., own the worldwide marketing rights for the sugar, called trehalose, which researchers predict will end blood-bank shortages for platelet cells.

Sports drink prototypeGlen StubbeStar Tribune"All you do is add water, and they're ready to go," said Dr. John Crowe, a researcher at the University of California at Davis and the nation's leading expert on trehalose.

Crowe expects the technology to become commercially available in three to five years. "It certainly will change blood-banking," he said.

Cargill is not conducting research into blood preservation but is adding the sugar in food and beverages, where it can enhance texture, taste and shelf life. Cargill also is supplying a purer grade of trehalose to researchers.

While Crowe's team is using trehalose to freeze-dry platelets, which help blood to clot, other researchers at Harvard Medical School are exploring whether it can help freeze women's unfertilized eggs.

Beyond that, scientists from Wisconsin to Japan are experimenting with trehalose as an ingredient to help store stem cells and preserve human transplant organs longer.

Trehalose has a number of special properties, such as protecting cell membranes and replacing water. Insects, plants and cold-blooded creatures manufacture trehalose at high concentrations when stressed -- something scientists have known for 30 years.

But only in the past decade did Hayashibara scientists in Okayama, Japan, perfect an enzymatic process, using bacteria in soil, to make trehalose. That has reduced to one-hundredth the initial cost of production and made possible widespread commercial use.

Hayashibara has given Cargill market-development rights in North and South America, Europe, Africa and the Middle East. Hayashibara retained rights in the rest of the world.

"We're really trying to develop the market and define new applications of trehalose," said Jim Kappas, director of international and emerging products for Cargill Health & Food Technologies.

Cargill, which began in Minneapolis 139 years ago as a grain trader, is increasingly involved in food-related technology with products such as trehalose, which it markets under the brand name Ascend.

Hayashibara, a pharmaceutical research firm that also manufactures Interferon, is making the trehalose from corn starch in Japanese factories. Cargill hopes to sell enough trehalose to western food and beverage companies to justify opening plants in the United States, Europe or on both continents, Kappas said.

The sugar's characteristics make it useful in sweeteners, seasonings, preserved and frozen foods, beverages and skin moisturizers.

Cargill scientists also are investigating other applications, including whether trehalose in the diet could play a role in managing blood sugar.

Imitating nature

Trehalose is produced in high concentrations in plants, insects and small, cold-blooded animals that survive severe dehydration, heat or icy temperatures. It's found in mushrooms, honey, yeast, lobsters, frogs, salamanders, most insects and other organisms.

Take, for example, the tiny brine shrimp. Baby boomers may recall them as the "sea monkeys" that were commonly advertised on the back of comic books. The fertilized shrimp embryos go through a dehydration cycle and are sold as coarse brown pellets. Toss them in salt water, put in an oxygen bubbler, and they hatch and swim away.

That principle is now being applied to cells as scientists try to mimic nature.

Crowe of the University of California at Davis is leading a $10 million project funded by the U.S. Defense Department researching whether trehalose can preserve blood platelets and, potentially, red blood cells and non-embryonic stem cells.

The goal is to extend the shelf life of platelets from five days to more than two years at room temperature.

The platelet research, in its eighth year, will need one more year of animal testing, with clinical testing in humans to follow, he said. If all goes well, it will be three to five years before the application is ready for market.

The military hopes to have packets of freeze-dried platelets that soldiers can carry onto the battlefield and apply when they're wounded to stop from bleeding to death, Crowe said. Beyond the platelets, the packets could include red blood cells, which carry oxygen. Right now, red blood cells are frozen in cumbersome containers.

Outside the battlefield, cancer and AIDS patients as well as trauma victims could benefit from the freeze-dried platelets.

Platelets, which must be stored at room temperature, must be discarded after five days on the shelf. By then, many of the cells are dying, forming clots, or are contaminated with viruses and bacteria. Trehalose stops the deterioration and protects cells, Crowe and other scientists say.

"After two years, the product is better than the five-day platelets in the blood banks, and they're more functional," Crowe said.

That could potentially help eliminate shortages at blood banks. At Memorial Blood Centers headquarters in Minneapolis, staff members meet each day to figure out how to generate 400 units of blood daily to meet local hospitals' needs. Though Minnesotans donate more than the national average, shortages remain a chronic problem. Every three seconds, someone needs blood.

If trehalose allows for unrefrigerated transfer of blood between blood banks, that could be a major advance for the distribution network.

"If you could get ahead a little, then your inventory management wouldn't be a nightmare," said Dr. Elizabeth Perry, associate medical director of Memorial Blood Centers. "It's what we all dream about."

High and dry

When he was in high school, Crowe became fascinated with tiny eight-legged organisms called tardigrades, which can live in moss for more than a century, surviving withering dehydration.

Years later, the reason became clear to Crowe and other researchers: tardigrades produce high concentrations of trehalose. The next problem was that scientists couldn't figure out how to get trehalose into cells. Now, they load cells with trehalose by piggy-backing on a process in which cells engulf nutrients.

Crowe directs the Center for Biostabilization, where 20 investigators work on storing mammal cells in a dry state. Trehalose protects the cells' membranes, proteins and DNA and replaces water in biological cells, which behave as if they still are hydrated.

Add water, and the cells once again function.

Nucleated cells, such as white blood cells, neural cells and stem cells, are more difficult to preserve than platelets, which don't have nuclei. Cells that contain a nucleus can be stored only if frozen to the temperature of liquid nitrogen, or about -320 degrees Fahrenheit, said Ann Oliver, an associate research scientist who leads a nucleated cell preservation project at Davis.

"If we were able to find a way to store these cells in a dry state, it would revolutionize the usage, storage and shipping of cells," Oliver said. "Large repositories of cells for researchers could be shipped without dry ice. You would not need all the copious washing and processing following thawing. It would be much easier for a doctor or surgeon or whomever to take a packet down off a shelf, add the water necessary and use the cells in a clinical setting."

Her team's research with non-embryonic stem cells is geared toward regenerative medicine. They work with Osiris Therapeutics, a private company in Baltimore, which is engineering tissue with non-embryonic stem cells to help heart attack victims and others. The firm's achievements include taking a mouse with a long bone defect -- similar to a person losing six inches of a shinbone -- and using stem cells in collagen to grow a new bone.

"It got up and walked away," Oliver said of the mouse, adding that the method might help amputees.

For consumers, it's possible that in the future they will be able to preserve their own platelets and blood cells, and carry them in unrefrigerated, convenient packets, including in glove compartments, Crowe said.

Bandages might also contain platelets, which would form clots when applied to wounds.

The military also is funding a University of Pittsburgh project into whether critically wounded or ill people could be placed in "suspended animation" as a way to buy time as victims are rushed to surgery. Researchers can now reduce dogs' body temperatures to 41 degrees and dramatically slow metabolic rates for about two hours, said Dr. Patrick Kochanek, director for the Safar Center for Resuscitation Research at the University of Pittsburgh.

Trehalose may be a possible additive, much like antifreeze, to prevent the cell membranes from being torn by ice fragments. That possibility intrigues Kochanek.

"This type of trehalose strategy, or some other type of cellular preservation, could have some merit," he said.

Though it's funded by the military, the project is equally important for future use on civilians with head injury, cardiac arrest and hemorrhagic shock, said Kochanek, also a physician at Children's Hospital of Pittsburgh.

He recently began to consider trehalose after a study found it may help arrest the slow degeneration caused by Huntington's disease. Researchers were able to deliver the sugar molecule into live animals' cells.

"That drug has crossed over from the dish to the intact organism," he said, "and that's a big hurdle."

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