From the Guardian: "The human body has tremendous capacity to repair itself after disease or injury. Skin will grow over wounds, while cells in our blood supply are constantly being manufactured in our bone marrow. But there is a limit to the body's ability to replace lost tissue. Cartilage cells are notoriously poor at regrowing after injury, for example. As a result, accidents and illnesses - including cancers - often leave individuals with disfiguring wounds or life-threatening damage to tissue. The aim of Molly Stevens, a nanoscience researcher at Imperial College, London, and founder of the biotech firm Reprogen, is a simple but ambitious one. Working with a team of chemists, cell biologists, surgeons, material scientists and engineers, she is developing techniques that will help the body repair itself when it suffers damage. This is the science of regenerative medicine. ... One approach that we have had considerable success with involves taking quite straightforward materials including simple polymers and using them to boost bone growth in a person. We made them into gels that we could inject into bones. The key to this technique lies with the fact that our bones are covered in a layer of stem cells. We inject our material under that layer and that wakes up those stem cells. They start to multiply and produce lots of new bone."