For years, biotechnology companies have tried to develop an artificial blood that could be used for emergency transfusions. But most efforts have stumbled over trying to reproduce hemoglobin, the protein that carries oxygen in red blood cells and is the essential element for artificial blood. The trouble is, when hemoglobin is outside the red blood cell, it clings too tightly to oxygen. Natural hemoglobin also breaks down into smaller units that can clog the kidneys and even cause them to fail. Trying to reproduce animal hemoglobin hasn't succeeded yet, either.
But now, Somatogen Inc. in Boulder, Colo., may have a solution. Through genetic engineering, the company's researchers have modified human hemoglobin so that it gives up its oxygen more readily and doesn't break down in the body. Then, they produce the material using yeast or bacteria. The substance, which is pure and doesn't break down, is free of side effects in animals. It is also up to 30% better at releasing oxygen than natural hemoglobin. Somatogen Vice-President Thomas B. King says the company expects to begin testing on humans by the end of summer, pending government approval.