Skele-Gro: how scientists are attempting to regrow bones Professor Alicia El Haj, director of the institute for science and technology in medicine at Keele University, said: "We are replicating the body's development to allow us to mend broken bones or treat orthopaedic injuries. You normally have cartilage that develops first to form a kind of template that the bone grows around. Then the more you exercise the denser your bones become. Patients with an injury are not going to be walking around and putting weight on their bones so they have problems building up dense bone. If they inject a solution containing stem cells into their injury and then strap on a magnetic bandage, this could do the work for them while they are still too injured to get out of bed. Working with scientists at Southampton University and Northampton University, Professor El Haj and her team have been developing the new technique to allow patients to receive a simple injection to help repair injuries. Stem cells could be taken from the patient's own body - the potential sources include skin cells - then suspended in a liquid gel that solidifies as it changes temperature once inside the body. This solid gel creates a new scaffold for the stem cells to grow on. Biological signals called growth factors in the gel also help guide cells to develop into cartilage. The researchers have also developed magnetic nanoparticles that they can attach to channels on the outer surface of the stem cells. Normally these channels open in response to the strain caused by exercise and encourage the cells to grow - an essential process to help bones grow thick and strong. By attaching the magnetic particles and applying a magnetic field, the scientists found they could replicate this. It means that they can simulate the effect of exercise on the developing bone without the patient needing to leave their bed. Professor El Haj said the team hoped to begin trails in humans within the next five years. She said: "The concept is that we have all the components that play a role in normal developmental processes in the body and we are creating them in the gel. By making it injectable, we could move this into a primary care situation where people could have an injection in the GPs surgery and then they are given a magnetic bandage to take home and wear.