Scientists at the Pentagon have completed the first phase of their plan to regrow soldiers' limbs, by turning human skin into the equivalent of a blastema - a mass of undifferentiated cells that can develop into new body parts.
Now, researchers are on to phase two: turning that cellular glop into a square inch of honest-to-goodness muscle tissue.
The Worcester Polytechnic Institute (WPI) just got a one-year, 570,000 dollars grant from Darpa, the Pentagon's blue-sky research arm, to grow the new tissues.
"The goal is to genuinely replace a muscle that's lost," biotechnology professor Raymond Page tells Danger Room. "I appreciate that's a very aggressive goal," he added.
According to Page, it's only one part in a larger, even more ambitious Darpa program, Restorative Injury Repair, which aims to "fully restore the function of complex tissue (muscle, nerves, skin) after traumatic injury on the battlefield."
Muscles are famous for their ability to regenerate. They're broken down and rebuilt with every gym workout.
But when too much of a muscle is lost - either from injury or illness - "instead of the regenerative response, you get scarring," Page said.
He's hoping to get a different result, by carefully growing fresh muscle, outside the body.
Step one will be trying to get those undifferentiated cells to turn into something like muscle cells. That means making sure the cells have myosin and actin - two proteins that are key to forming the cellular cytoskeleton, and to building muscle filaments.
Then, Page and his team will try to get those cells to form around a scaffolding of tiny threads, made of biomaterial.