Stem cell hope for bone fractures

UK scientists hope to mend shattered bones and damaged cartilage using a patient's own stem cells. They are developing a "bioactive scaffold" to protect the stem cells and encourage them to grow into bone or cartilage when placed in the body.

The Edinburgh University team hope the technique, which uses stem cells from blood and bone marrow, will be tested in patients within two years. Surgeons said it could help repair trauma injuries too severe to heal. The £1.4m project could also eventually have an impact on treating conditions such as osteoarthritis.

Dr Brendon Noble, who works in the University of Edinburgh's MRC Centre for Regenerative Medicine said initially they would look at mending cartilage injuries which do not tend to heal well or bone fractures caused by severe trauma such as motorbike accidents. Elderly patients with fractures also tend to heal less well, he said.

The key to success would be to get the "recipe" right for encouraging the stem cells to grow in what are effectively harsh environments, he explained. "A lot of research that has gone before is working out what will drive them down the route to become a specific cell type. The next stage is trying to think of innovative ways to encourage them to do that in the body - often we can do things in the laboratory and that's easy but we tend to forget that the cells in the patient were not happy in the first place."

The scaffold consists of a fairly rigid mesh structure, coated or impregnated with a drug that helps the stem cells take hold. As well as using stem cells from bone marrow, Dr Noble's team is working with the Scottish National Blood Transfusion Service to culture bone forming cells from blood. This would mean the patient does not have to undergo surgery to harvest the cells.

Dr Noble added: "Half of us will have orthopaedic surgery in our lifetime. "We are also living longer and want to remain more active in later life so such problems are going to become more prominent and more expensive."

Professor Chris Moran, member of the British Orthopaedic Association and expert in trauma surgery at the University of Nottingham, said this kind of research meant in the future surgeons might be able to repair trauma injuries too severe to heal by current techniques and even replace bone lost to cancer. But he added: "In order to move this technology from the laboratory to the operating theatre, the scaffold will need to be compatible with the human body and resist rejection."