A team of French scientists and doctors has successfully injected blood cells derived from hematopoietic stem cells (HSCs) into a living human. This first of its kind study answered two questions: whether cultured red blood cells could mature inside a body, and if the resulting cells would survive long enough to be useful. Although it’s still early days, the answer to both questions seems to be ‘yes’.
The experiments were conducted in two phases. First, the scientists collected HSCs from a donor, and used them to generate billions of cultured red blood cells (cRBCs). These cRBCs were injected into mice. Because the cultured cells had been radioactively labeled, the scientists were able to confirm that the cRBCs continued to mature properly. Next, the researchers repeated the experiment with HSCs from a different donor, but this time they injected the resultant cRBCs back into that same donor. After 26 days, about half the injected cells were still viable, consistent with the 28 day half-life of natural red blood cells.
Being able to produce blood cells abundantly and without risk of infection or rejection would be an enormous advantage. Imagine donating a few cells prior to a surgical procedure, and then knowing that a large supply of your own blood cells was waiting for you, in case of need.