HELP ON THE WAY: HemoBioTech, Inc.'s HemoTech is expected to not only suppress hemoglobin's inherent toxicity but also serve to improve blood flow and even spur the creation of new red blood cells. Image: Courtesy of HemoBioTech, Inc.
Researchers are stepping up efforts to develop a safe blood substitute amid a growing demand and dwindling supply of the real thing to treat trauma victims and blood disorders such as potentially deadly types of anemia.
Their major hurdle: to come up with a replacement for hemoglobin (an iron-enriched protein in red blood cells that transports oxygen from the lungs to the rest of the body) that can be directly introduced into the human circulatory system. The problem is that the body breaks down and eliminates real hemoglobin that is not protected by red blood cells, a process that can be toxic to the kidneys, constrict blood vessels (resulting in hypertension), and cause inflammation.
The Texas Tech University Health Sciences Center in Lubbock and Dallas-based blood substitute developer HemoBioTech, Inc., believe they have a chemically modified bovine hemoglobin called HemoTech that not only suppresses hemoglobin's inherent toxicity but also serves to improve blood flow and even spur the creation of new red blood cells. "This represents a learning from all of the failures that have proceeded us over the past 35 years," says Arthur Bollon, HemoBioTech's chairman and chief executive officer. Texas Tech University spun off HemoBioTech in 2002 to commercialize HemoTech.
"Creating an effective substitute for human blood has been an elusive dream for many decades," says Jan Simoni, associate research professor in Texas Tech's surgery department and HemoBioTech's acting vice president for research and development. "Our product addresses all the intrinsic toxicity issues."
HemoBioTech's use of modified bovine hemoglobin addresses the two biggest issues affecting today's blood supply: There is not enough to go around and the available blood runs the risk of contamination. "Bovine hemoglobin is an unlimited source of raw material for making blood substitutes," Simoni says. Hemoglobin from bovines (which include antelopes, bison and cattle) also does not carry human-born viruses such as HIV and hepatitis. It could, however, potentially carry other pathogens that might be transmitted to humans, such as the protein that causes mad cow disease. But Simoni says Texas Tech scientists have developed a method to effectively filter out such threats.
He adds that real blood must be carefully screened, noting that one in every 60,000 units may carry hepatitis B and one in every 500,000 units, HIV; other contaminants of concern are hepatitis C and the human T-cell leukemia virus.
"The World Health Organization estimates that 100 million units (45 million liters) of blood are needed worldwide per year," Simoni says. "There are not enough blood donations to meet the demand when you consider that the demand is increasing by 1 percent per year, while donations are decreasing by 1 percent per year." The U.S. alone annually uses about 12 million units, and by 2030 it is projected that there will be a shortage of as much as four million units of blood.
HemoTech also eliminates the need to match blood types between patients and donors, because pure hemoglobin is not affected by varying factors found in human blood. In addition, HemoTech has a shelf life of at least 180 days—significantly longer than the typical 42-day period during which donated blood can be used.
In the early 1990s HemoTech was used in Zaire to successfully treat nine children with sickle-cell anemia. In fact, HemoTech constituted 25 percent of each patient's blood volume during the treatment. None of the patients suffered toxic side effects, Bollon says.