A new gene therapy technique to grow bone from gum tissue may make life easier for patients who need bone grafts, by eliminating painful removal of bone from a donor's hip.

R. Bruce Rutherford and colleagues at the University of Michigan School of Dentistry take a snippet of gum tissue and grow more cells in the lab. They then use recombinant virus to spike the cells with genes for factors that promote bone growth. Next, the researchers seed surgical gel with the treated cells, shape it to fit the area of the graft and implant it. The cells begin producing the growth factors, which prod surrounding bones to grow into the space, and even create new bone themselves. In tests on rats, large areas of bone removed from the animals' skulls grew back in only one month.