Artificial blood grown in a lab from stem cells is one step closer to being available to people with complex blood types for whom it is difficult to find matching donors.
Teams around the world have been trying to make artificial red blood cells, as an alternative to donated blood.
Scientists with the National Health Service (NHS) in UK have induced stem cells sourced from adult and umbilical cord blood to make lab-grown red blood cells. The NHS now say they could have manufactured blood ready for use in clinical trials with human volunteers within two years.
The first trial is likely to be small — 20 volunteers will be transfused with a small amount (5-10 ml) of lab-produced blood. It will compare the survival of red blood cells grown in the lab with that of standard red cells from blood donors.
The health authority say there is a need to increase the availability of better-matched blood for patients with rare blood types. These include patients with blood conditions like sickle cell anemia and thalassemia, who require regular blood transfusions.
The intention is not to replace human donation, says Dr. Nick Watkins, NHS Blood and Transplant assistant director of research and development, but to offer specialist treatment for specific patient groups. The aim is to develop transfusion, transplantation and regenerative medicine over the next five years.
However, blood donations would continue to be needed. The NHS collects around 1.7 million units of blood each year, with hospitals in the country needing around 6,000 units a day. The pressure is building not only because of greater demand, but also because of a shortage of donors. In 2014, there were 40 percent fewer people volunteering as new donors compared with 10 years earlier.
Also, in 2013, a study reported that the shelf life of blood is nearer to three weeks than the six weeks that blood banks regard as standard for blood used in transfusion. The researchers came to this conclusion after showing that red cells in stored blood lose their ability to deliver oxygen where it is most needed once the three-week shelf life is exceeded.