Blood grown from stem cells could transform transfusions
In 2007, a team of researchers from the UK and Irish Blood services responded to an oddly specific call from the US military. They wanted scientists to help them build a machine, no bigger than two and a half washing machines, that could be dropped from a helicopter on to a battle field and generate stem-cell-derived blood for injured soldiers.
The team’s application was not successful, but they refocused their efforts and set off on a more utopian mission – to develop a similar technology to create a limitless supply of clean, laboratory-grown blood for use in clinics around the world. Using blood made from stem cells would unshackle blood services from the limits of human supply, and any risk of infection would be removed.
They’ve been working with embryonic or induced pluripotent stem cells, which, given the right culture conditions, can differentiate into any type of cells. Still at least a year from human testing, the team have tweaked their protocol to select only red blood cells.
“Because we make them from human cells they are as nature intended,” says Joanne Mountford, of the University of Glasgow, who leads the project along with Marc Turner, the medical director of the Scottish National Blood Transfusion Service.
“It’s the same thing your body makes but we’re just doing it in a lab.”
Lab-grown blood has advantages over blood from a donor. “If I take a bag of blood from your arm, some cells would be brand new,” she explains.
[quote_box_left]“But some of them would be 110 or 120 days old and about to die. These cells won’t do you much good.” [/quote_box_left]Using engineered red blood cells from a single batch, the team proposes, will ensure that recipients receive younger, fresher, and potentially more effective blood.
Another advantage is that they are making type-O blood, which can be given to practically all patients – including those with rare AB-negative blood. A limitless supply of this type of blood would remove the logistical headache of juggling different types of blood, simplifying global distribution logistics, and allowing the blood to flow more freely to where it is needed.
Ted Bianco, director of Innovations at the Wellcome Trust, which funds the project, speaks excitedly about its potential, but says that challenges exist in translating such research to clinical practice, especially when trying to replace human blood donors as the source of supply for lifesaving transfusions.
A major hurdle, says Mountford, is scaling up. They can produce about 10 billion red blood cells per batch but have a long way to go – an average bag of blood from a donor contains a trillion cells. Another issue is the risk that pluripotent stem cells, which by definition can turn into any cell, could differentiate into cancerous cells if any remained after the 31-day protocol.
[quote_box_center]“The odds of there being any left is incredibly low,” Mountford says, explaining that the blood will go through two terminal filtration processes to remove any undifferentiated stem cells, “and we’re just finalising the data on whether there is any persistence of these cells.”[/quote_box_center]
Once they have the all-clear, they will move on to testing in three people in 2016-17, before hopefully moving on to a trial for safety and effectiveness in patients with beta thalassemia, an inherited blood disorder, in 2018-19
[quote_box_center]“But let’s remember,” concludes Mountford, “that in the western world we have fantastic blood services, so people should keep donating. It’s in the developing world where the infrastructure is lacking – our challenge is to get this done at a cost that is globally relevant.”[/quote_box_center]