Artificial implantable bone marrow
An artificial bone complete with a bone marrow cavity capable of making new blood cells has been tested successfully in mice by US scientists.
University of California San Diego researcher Yu-Ru Shih and his colleagues, who have presented their work in the journal PNAS, used two polymers, methyl-methacrylate and also a form of polyethylene glycol, to make a bone template comprising an outer, hard mineralised layer and a porous, spongy centre.
This structure recapitulates what happens inside long bones like the femur where the spongy interior is home to bone marrow stem cells that produce new blood cells.
Implanted into mice, the new material connected itself to the blood supply and was capable to producing new blood cells.
When loaded with labelled stem cells from a donor animal, blood tests at both 4 and 24 weeks after implantation showed that the small artificial bone, measuring just a few millimetres in length, was contributing about 4% of the blood cells in circulation.
The work is important because it may offer doctors a new way to perform bone marrow transplants. Instead implants "pre-loaded" with bone marrow cells could be implanted into recipients, improving the safety of the procedure.