“We have shown that we can grow predictable volumes of bone on demand,” said V. Prasad Shastri, assistant professor of biomedical engineering at Vanderbilt University who led the effort. “And we did so by persuading the body to do what it already knows how to do.”

For people with serious bone disease, it may even be possible to grown replacement bone at an early stage and freeze it so it can be used when it is needed, said Prasad.

Despite the fact that living bone is continually growing and reshaping, the numerous attempts to coax bone to grow in vitro have all failed. Recent attempts to stimulate bone growth in vivo have had limited success but have proven to be extremely complex, expensive and unreliable.

Shastri and his colleagues took a new approach that has proven to be surprisingly simple. They decided to take advantage of the body’s natural wound-healing response and create a special zone 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, a species with bones that are very similar to those of humans, the researchers were delighted to find that this zone, which they have dubbed the “in vivo bioreactor,” filled healthy bone in about six weeks. And it did so without having to coax the bone to grow by applying the growth factors required by previous in vivo efforts. 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.

“The new bone actually has comparable strength and mechanical properties to native bone,” said Molly Stevens, currently a reader at Imperial College in the United Kingdom who did most of the research as a post-doctoral fellow at MIT. "And since the harvested bone is fresh, it integrates really well at a recipient site."

MEDICA.de; Source: Vanderbilt University