Colorado researchers have used genetic engineering to produce a form of artificial blood, representing a significant step in the search for a solution to the worldwide shortage of blood.
Researchers from Somatogen in Boulder report today in the British journal Nature that they have begun human trials with the blood, which is produced in bacteria.
The artificial blood is a genetically engineered form of hemoglobin, the complicated protein that -- enclosed in red blood cells -- carries oxygen from the lungs to tissues throughout the body. The genetically engineered hemoglobin persists in the blood of dogs much longer than the naturally occurring form and causes no adverse side effects, they report. In separate studies not yet published, they have also found that the material effectively carries oxygen to tissues, pulmonologist Steven Shoemaker of Somatogen said.
Many companies have been searching for an artificial blood because of the annual worldwide shortage of about 100 million units of blood and the military's need for blood replacements that can be stored in field conditions without refrigeration.
An artificial blood also would virtually eliminate the risk of contracting AIDS, hepatitis and other viral diseases through transfusions. Although AIDS is no longer considered a significant risk in transfusions, as many as 250,000 of the 4 million Americans who receive transfusions each year contract hepatitis as a result.
An artificial blood would also eliminate the need to match blood types before a transfusion because only the hemoglobin would be used. Currently people receive transfusions of either whole blood or red blood cells, both of which require matching.
The new research has two important aspects: It provides potentially large new source of hemoglobin, and it eliminates the need to perform chemical modifications on the hemoglobin to make it perform effectively.
Because Somatogen's artificial blood is made by genetic engineering and does not have to be chemically treated, impurities should be less of a problem, Mr. Shoemaker said.