Researchers from the Massachusetts Institute of Technology have developed an implantable tissue scaffold that is coated with bone growth factors that are released slowly over a few weeks. When applied to bone injuries or defects, the coated scaffold induces the body to rapidly form new bone that looks and behaves just like the original tissue. This type of coated scaffold could offer an improvement over the current standard for treating bone injuries, which involves transplanting bone from another part of the body. Two of the most important bone growth factors are platelet-derived growth factor (PDGF) and bone morphogenetic protein 2 (BMP-2). Efforts to treat bone injury with these growth factors have been hindered by the inability to effectively deliver them in a controlled manner. When very large quantities of growth factors are delivered too quickly, they are rapidly cleared from the treatment site and can induce unwanted side effects. To release growth factors slowly over several days or weeks, the researchers created a thin, porous scaffold sheet coated with layers of PDGF and BMP. An advantage of this approach is that the scaffold is biodegradable and breaks down inside the body within a few weeks. The researchers aim to begin testing the system in larger animals, and eventually moving it into clinical trials.