Self repair of bones
the human body never ceases to amaze scientists. The latest admirers are biomedical engineers who have unveiled the body's ability to grow healthy new bones in one part, which can then be used to repair damaged bone at a different location.
The research has shown that predictable volumes of bone can be grown on demand, according to V Prasad Shastri, assistant professor of biomedical engineering at Vanderbilt University, usa, who led the effort. Their study was recently published online by the Proceedings of the National Academy of Sciences, usa .
Orthopaedic surgeons repair serious bone breaks usually by removing small pieces of bone from a patient's rib or hip and fusing them to the broken bone. Shastri and his colleagues took a new approach that proved surprisingly simple. They decided to take advantage of the body's natural wound-healing response by creating a special zone, termed the "in vivo bioreactor', on the surface of a healthy bone in hopes that the body would respond by filling the space with new bone. Working with mature rabbits, which have bones similar to those of humans, the researchers were delighted to find that this zone filled healthy bone in about six weeks. And it did so without having to coax the bone to grow by applying any growth factors. Furthermore, they found that the new bone can be detached easily before it fuses with the old bone, leaving the old bone scarred but intact.
If the new method is confirmed in clinical studies, it will become possible to grow new bone for all types of repairs instead of removing it from existing bones. For people with serious bone disease, it may even be possible to grow replacement bone at an early stage and freeze it so it can be used when it is needed, says Prasad.
"This research has important implications not only for engineering bone, but for engineering tissues of any kind,' adds co-author Robert S Langer of the Massachusetts Institute of Technology in the us.