Human blood grown from stem cells

Scientists in the United States have produced vials of human blood grown from emryonic stem cells for the first time, potentially providing an almost limitless supply of human blood. Scientists, from Advanced Cell Technology (ACT) in Massachusettes, led by Robert Lanza, say that if this blood was the universal donor group O, it could be safely be given to anyone who needed a transfusion.

Such stem cell derived blood would also eliminate the possibility of transmitting blood-borne diseases through a transfusion. While a few red blood cells have been created from embryonic stem cells before, the ACT team is the first to mass-produce them on the scale required for medical use. They also showed that the red cells were capable of carrying oxygen, and that they responded to biological cues in similar fashion to the real thing. About two thirds had no nucleus, which suggests that they are fully fledged adult red blood cells, and the researchers hope to bring this closer to 100 per cent. Details of the research are published in the journal Blood.

Clinical trials on humans are now needed to show that the stem cell-derived blood is safe and effective.