They injected a protein that plays a central role in bone development — called Wnt — and were able to stimulate rapid bone growth. Researchers have known the protein could be useful in humans, but it has been difficult to purify and dissolve, making the substance hard to apply. The Stanford team overcame this problem by using molecular bubbles called liposomes that could be suspended in liquid for delivery into the body.
In the experiment, the scientists drilled holes in the leg bones of mice with a dental drill (the mice were anesthetized and given painkillers). Some of the mice received injections of the Wnt-covered liposomes and others were injected with the Wnt protein without the liposome carrier. Within three days, the animals who received the Wnt-covered liposomes had 3.5 times more bone than the other mice. These animals were completely healed in 28 days, while the other mice were still in the process of repairing the injury.
It's possible that using Wnt to generate healing may also produce tissue that is more functional and lacks scars.
The study is published online this week in the journal Science Translational Medicine.
— Shari Roan
Photo credit: Advanced Cell Technology Inc.