Fake cells, real benefits?

Artificial red blood cells, which could reduce blood transfusion risks such as infection and immune reactions, have been successfully created by packaging the oxygen-carrying protein hemoglobin in bubbles of fat, according to a report in the Dec. 6 SCIENCE from researchers at the University of California at San Francisco. The cells, called neohemocytes, also represent "one step along the road of constructing biological systems from scratch," co-researcher C. Anthony Hunt told SCIENCE NEWS.

The process encapsulates hemoglobin from outdated donor blood in bilayer membranes of lipids (see thin-section electron micrograph above.) One-twelfth the size of real human red blood cells, the artificial cells could be used to xygenate poorly vascularized tissues, such as tumors and the brain, to facilitate treatment. STudies suggest that, although these cells are cleared from the bloodstream more rapidly than are real cells, their lack of blood group antigens and their shelf life of six months make them a viable choice in the treatment of trauma patients, as a temporary substitute for real red cells and for tissue irrigation during surgery.

The next step, Hunt says, is the difficult "scale-up" process to produce enough material for clinical trials in humans. He estimates the final product will cost two to five times as much as real blood. The artificial red cells, however, are not expected to fulfill all the needs now satisfied by whole blood ro packed red blood cells. Other researchers are studying chemically treated free hemoglobin and an entirely synthetic perfluorocarbon oil emulsion (SN: 8/28/82, p. 137) as possible oxygen carriers.