Here's the first lab-grown limb

A team at Massachusetts General Hospital has successfully grown a rat forearm in the lab.

They are hoping that the procedure could one day result in the regeneration of human limbs which could then be transplanted to amputees.

According to one of the researchers, the main challenge overall is that each of the components of the limb, including the muscles, bone, blood vessels, and nerves need to grow separately yet work together within a supporting matrix.

They were able to overcome this, at least partly, by using the matrix structure of a dead rat after all its cells have been removed but with the nerve and vasculature systems still in place.

The clean frame was then injected with the cultured cells of muscles and other components, eventually resulting in positive growth activity.

The scientists were able to get the paw to curl and expand, and the muscles fibers on the whole reacted to electrical stimulation.

They even surgically attached the limb to a living rat, and found that blood circulation was entirely possible, and thus the limbcould stay alive.