A protein produced naturally by the body can speed up bone growth and may offer a route to fixing fractures more quickly, researchers report.
They found the protein, known as Wnt, sends a signal that activates bone stem cells to make new bone, and say the finding could also improve bone grafts.
While the findings were tested in mice, humans and mice have the same biology in this area.
"We believe our strategy has the therapeutic potential to accelerate and improve tissue healing in a variety of contexts," says Dr Jill Helms of Stanford University in California, who led the study that appears in the journal Science Translational Medicine.
Scientists have known for a long time that many animal species use Wnt to regenerate tissue. But it is hard to work with and will not dissolve in water.
Helms and colleagues found a way to implant pieces of genetically enhanced Wnt protein in little bubbles of a fatty material called liposomes.
"This allowed us to start testing its activity in animals," says Helms.
When they drilled holes in the bones of sedated mice and injected the Wnt liposomes, the Wnt caused bone stem cells at the injury site to divide and mature into bone-forming cells faster, the researchers found.
"Skeletal defects treated with liposomal Wnt healed faster," they write. Mice treated with Wnt had 3.5 times more new bone after three days than other nice.
More than bone
Other tissues use Wnt to regenerate, too, they say. "Wnts are implicated in the repair of multiple organs and tissues."
They plan to test their approach in treating skin wounds, strokes and heart attacks.
"After stroke and heart attack, we heal the injuries slowly and imperfectly, and the resulting scar tissue lacks functionality," says Helms.
"Using Wnt may one day allow us to regenerate tissue without scarring."