Broken bones mended with stem cells and plastic

The degradable polymer material is the result of a seven-year collaboration between the Universities of Southampton and Edinburgh. The researchers report their work in a paper published in the journal Advanced Functional Materials. In their background information they note how bone tissue regeneration is often needed after trauma, where "substantial bone or cartilage loss may be encountered", and this drives researchers to develop new biomaterials, especially those that can form a 3D structure.

Their new material is "strong enough to replace bone and is also a suitable surface upon which to grow new bone," says study author Mark Bradley, a professor in the University of Edinburgh's School of Chemistry, in a statement.

Using what the statement describes as a "pioneering technique", Bradley and colleagues created and experimented with hundreds of candidates before settling on a material that was robust, lightweight, and able to support bone stem cells.

The new technique, called "solvent blending", is a process that "avoids complications associated with conventional thermal or mechanical polymer blending or synthesis, opening up large areas of chemical and physical space, while potentially simplifying regulatory pathways towards in vivo application," they write.

The material they finally settled on is a polymer blend of three types of manmade and natural plastics and can be inserted into broken bones to encourage real bone to re-grow.

The polymer blend is like a scaffold made of honeycomb that allows blood to flow through it. Stem cells from the patient's bone marrow that are in the blood attach themselves to the scaffold and grow new bone tissue.

As time goes on, the material degrades, allowing the re-grown bone to replace it.

The researchers have already tested it in the lab and in animals, and are now looking to move into human clinical testing.

In June 2012, US scientists reported finding a way to grow new bone using fresh, purified stem cells from fat tissue that produces better quality bone faster than conventional methods.