ARUN RATH, HOST:
We're now a step closer to being able to grow replacement parts for our own bodies. In their lab at the Massachusetts General Hospital, Dr. Harold Ott and his team have grown the entire forelimb of a rat.
HAROLD OTT: I think this is a very exciting right now, because basically what we can do is we can push cells to become hard cells or muscle cells. But we're not quite there yet to then guide them to grow into a full-blown heart or lung. It's just highly complex. And it's hard to do in a dish.
RATH: The scientists use a process called decellularization. They remove the existing living tissue from an existing rat arm and repopulate the scaffolding left behind with new, living cells. And the arm they've created looks disturbingly real. You can check out the photos on our website - flesh, muscles, everything. That's not all. They ran an electrical current through the muscles tissue and the little arm began to twitch.
OTT: Those muscles - those little muscles were not strong enough yet to move the entire arm. But they were strong enough to move on their own and to have measurable contractile force.
(SOUNDBITE OF FILM, "FRANKENSTEIN")
COLIN CLIVE: (As Henry Frankenstein) It's alive. It's alive. It's alive.
RATH: OK, so Dr. Ott didn't quite flip out in Dr. Frankenstein fashion, but he is very excited about his creation.
OTT: Because it finally proved that we can regenerate functional muscle on this matrix. It sort of really showed us that this is a platform that eventually has the potential to regenerate functional composite tissue for patients.
RATH: Now that they've created the arm, Dr. Ott says it's time to work on making the limb re-attachable and fully functional.
OTT: The next step will be now to apply the cellular part to the cell technology of this paper to human or patient-derived cells and to answer quite a bit more questions. As you can imagine, this scaffold not only has to be alive, but eventually, we hope that it will connect back to the patients through recipients' nerve system in order to become fully functional.
RATH: They've since applied this technology to arms of primates in hopes of building a framework on the human scale.
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