The scientists of Massachusetts General Hospital in Boston made news earlier this month after they published research in the journal Biomaterials describing the process they used to create the world's first artificial limb in the laboratory.
The fact that scientists have now grown the entire forelimb of a rat in a lab has huge implications for human medicine, where artificially grown limbs or other organs would carry a significantly lower chance of rejection by the body that transplants from donors.
Dr. Harold Ott, head of the Ott Laboratory for Organ Engineering and Regeneration, led the team that was able to "engineer rat forelimbs with functioning vascular and muscle tissue," according to the hospital.
The scientists used a process called decellularization, where they removed the living tissue from an existing rat limb, leaving just the "framework" of proteins behind. They then re-populated this "scaffolding" with healthy, living cells.
While not a limb from scratch, the holy grail of lab grown organs, it is the first step leading to such lab grown organs, which could be used in transplants.
"The loss of an extremity is a disastrous injury with tremendous impact on a patient's life," Ott and his team wrote in Biomaterials. "Current mechanical prostheses are technically highly sophisticated, but only partially replace physiologic function and aesthetic appearance."
"[Ott's] team and others at MGH and elsewhere have used this decellularization technique to regenerate kidneys, livers, hearts and lungs from animal models, but this is the first reported use to engineer the more complex tissues of a bioartificial limb," Mass General said in a press release.
Ott said his team's work "finally proved that we can regenerate functional muscle." The team was able to prove this when they ran an electrical current through the muscle tissue and the little limb began to twitch.
The team is now working on the arms of primates, which seems to be showing that the process might work on humans.