The NHS is getting some new blood (Image: Ann Cutting/Getty)

Artificial blood will soon be tested in the UK for the first time. New Scientist takes a look at how – and why – this blood is made.

What is artificial blood?

Blood substitutes aim to replicate one particular job of real blood: supplying oxygen to tissues. In other words, the goal is to find an alternative to oxygen-carrying red blood cells that could be used for transfusions. Today, the UK National Health Service announced it plans to start transfusing people with artificial blood by 2017 – the first clinical trials of this kind anywhere in the world.


Are there many different types?

More than you might think. Some researchers are working on blood substitutes based on the haemoglobin molecule that binds oxygen in red blood cells. One such product – Hemopure – is based on bovine haemoglobin, and was approved for human use in South Africa back in 2001. It is currently undergoing clinical trials in the US to help treat life-threatening anaemia.

Others are investigating whether it’s possible to make entirely synthetic substitutes based on oxygen-carrying molecules like perfluorocarbons. But the version the NHS will trial is based around real red blood cells that were generated in the lab.

How are these cells made?

From stem cells. Researchers have previously managed to take hematopoietic stem cells from volunteers’ bone marrow and encourage them to grow into red blood cells using chemical growth factors. The NHS will probably use a similar approach, although it also plans to explore using blood from umbilical cords – another rich source of hematopoietic stem cells.

Will it work?

It should do. Robert Lanza, chief scientific officer at Ocata Therapeutics – formerly Advanced Cell Technology – in Marlborough, Massachusetts, and his colleagues first grew red blood cells on a large scale in the lab in 2008. In 2011, Luc Douay at Pierre and Marie Curie University in Paris, France, and his colleagues performed the first small transfusion of such lab-grown red blood cells into human volunteers. These cells behaved just like normal red blood cells, with about 50 per cent still circulating in the blood 26 days after the transfusion.

So there are no more hurdles to overcome?

Perhaps there is still one – volume. Douay said in 2011 that it will be a big challenge to scale up the technology to generate enough artificial cells for regular transfusion. In his team’s experiment, they injected 10 billion artificial cells into volunteers, but that’s equivalent to only 2 millilitres of blood.

Although Lanza’s team was able to generate 100 billion cells, their technique used controversial embryonic stem cells. Even then, they produced about a twentieth of the number of cells that would be needed for a single transfusion.

Why even bother then?

The number of new volunteers giving blood fell in England and North Wales by 40 per cent last year. Because of this decline, the NHS says alternative supplies could become increasingly vital for its day-to-day operations. Artificial blood might also be an effective way of helping people with rarer blood types, for whom compatible donors are particularly thin on the ground.