- ARLINGTON, Va (UPI) -
Scientists
may be close to an elusive goal of creating artificial blood, a
breakthrough
that could ease shortages and save countless lives.
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- Dr. Jerry Squires, vice president and chief scientific
officer for the American Red Cross, told United Press International on
Thursday that blood substitutes are under development for use in
emergencies
or during lengthy surgeries.
-
- "There are time constraints on most of the
artificial
blood products under development, in that they stay in the body only a
short period of time. That will limit their use," said Squires, who
writes on the subject in the current issue of the journal Science.
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- One of blood's important tasks is to deliver oxygen
throughout
the body and remove carbon dioxide. This task is accomplished by
hemoglobin,
a protein contained within the red blood cells. Squires said researchers
trying to develop blood substitutes have primarily concentrated on copying
the oxygen-transporting traits of hemoglobin.
-
- "There are at least three modified hemoglobin
products
currently in advanced clinical trials," Squires said.
-
- Biopure Corp. in Cambridge, Mass., has produced
artificial
hemoglobin from the red blood cells of cows. It has been cleared for use
in the Republic of South Africa and is awaiting Food and Drug
Administration
review of its phase III clinical trials in the United States.
-
- U.S. Northfield Laboratories, in Oakden, South Australia,
has developed Polyheme, a polymerized human hemoglobin product, and Hemosol
Inc. in Toronto has developed Hemolink, a partially polymerized human
hemoglobin
that also is under FDA review.
-
- "There's no question about the need for blood
substitutes,
both in the United States and in developing countries," said Chien
Ho, a professor of biological sciences at Pittsburgh's Carnegie Mellon
University, and a pioneer in hemoglobin research.
-
- "The United States' blood supply is very safe, but
the supply of donor blood is shrinking. In the developing world, widespread
disease limits blood donations. In both instances, a blood substitute would
fill a very urgent need," Ho said.
-
- As with any medical advancement, there have been setbacks
along the way. Early trials of artificial blood indicated some products
could cause high blood pressure, or even strokes.
-
- Squires believes continued research will reduce those
risks and that any approved blood substitute will be safe.
-
- "Right now our blood supply is extremely safe, so
we would not want to trade that low risk for something that carried a
higher
risk," Squires said.
-
- In the United States, where the safety of the blood
supply
has constantly improved over the past 20 years, artificial blood would
most likely be used in emergencies, according to Squires. It would
eliminate
the need to match blood types before providing transfusions to trauma
victims.
When donor supplies get tight, artificial blood could help alleviate the
shortage.
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