
Researchers at Massachusetts General Hospital have used human cells to regenerate the arm of a macaque monkey. The aim is to one day grow human arms for transplantation.


The process involves removing all cells from the using fluids and detergents. Cells are then regrown and replaced using human progenitor cells, which can develop into blood, nerve or muscle cells.

Harald Ott and his team at Massachusetts General Hospital recently regenerated the limb of a rat in the lab, by flushing the arm of all cells and then regrowing them with cells from a different rat.

The process takes place in a tightly controlled environment with set temperatures, humidity, pH, oxygen levels, and pressure. Pictured, the regrowth of the rat arm inside a bioreactor.

Salamanders, such as the red spotted newt, can regrow an impressive range of body parts, including full limbs. Maximina Yun at University College London is studying their abilities to explore the potential to apply this to humans.

The main option for amputees today are prosthetic limbs or transplants, where available. The use of transplants requites recipients to take lifelong immunosuppressive drugs which increase the risk of other infections and potential development of cancers.




