Out on a limb: Pioneering scientists grow monkey arms in the lab

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(CNN)In a U.S. laboratory, a monkey arm is stripped down as far as its individual cells. All that's left behind is a bare, frail scaffold.

But that's not the end of the road for this arm. The scaffold is rebuilt with infusions of cells from another being -- be it a monkey, or a human -- which grow and transform the limb.
The aim is ultimately to restore the limb to its fully functional form. But this transformed limb will contain the blood, bones, muscles, cartilage -- and more -- not of the animal it once was, but instead, the animal providing these new cells.
The hope is to eventually use human cells to make limbs that can be transplanted in humans -- and the technology is already being trialled in monkeys.

    Replacing lost limbs