Question: is it possible to grow a limb from stem cells if someone had lost an arm

Jeremy Green answered on 14 Jun 2011:

Not yet, but perhaps one day.

Children can regrow the tips of their fingers if injured below the age of about five years old, and we don’t really know why this ability is lost.

Skin can be and is cultured in dishes successfully for skin grafts for burn victims but a whole arm or leg is an extremely complicated bit of kit: think of the dozens of little bones in the hand and arm, the many nerves and blood vessels, the muscles, etc. etc., so although each of these cell types can be grown from stem cells in the dish, doing the wiring (nerves) and plumbing (blood vessels) to put these together is a tall order. My guess is that in the next 15-20 years, more and more of limbs will be grown from stem cells, but it will be for bits of a limb rather than the whole thing.