Doctors from Massachusetts General Hospital in Boston have created the world’s first-ever “biolimb” — a functional body part grown from the recipient's living cells. Although the science is decades away from being used on humans, it’s already causing a stir in the medical world, but just how does this achievement compare to recent advancements in prosthetic technologies?

In what may be the first step toward creating real biologically functional limbs for amputees, a team of Massachusetts General Hospital scientists, led by Dr. Harald Ott, were able to use a dead rat's forelimb as the framework to grow a completely new arm. When the new limb was attached to a living rat, it quickly filled with blood and the animal was even able to flex its new paw, New Scientist reported.

The technique used to create the biolimb involves taking an organ from a deceased donor and decellularizing it, or stripping it of all its soft tissue to leave only the “scaffold” of the organ remaining. This is done with the help of specialized detergents. As reported by New Scientist, in the case of the rat limb, this “scaffold” included the collagen structures that make up blood vessels, tendons, muscles, and bones.

After the decellularization, the organ is then recellularized by grafting cells from the recipient into the scaffold. The recellularized limb is then treated with a nourishing substance to promote tissue growth. Afterward, the new limb is ready to be attached to its recipient, and in two to three weeks the blood vessels and muscles have completely rebuilt.

Recent research has truly revolutionized the field of transplant surgery, with doctors being able to transplant everything from an individual’s face to even the penis. However, the biolimb method differs from other examples of organ transplant because the new limb is made completely from cells of the recipient, therefore eliminating the risk of organ rejection. As a result, there's no need for using immunosuppressant drugs, which can weaken the immune system to dangerous levels. There would also be no risk of an organ transplant changing a recipient’s personality, a rare yet proven medical phenomenon.

So far, the team has decellularized around 100 rat forelimbs and recellularized about half of those, but the science is still decades away from human testing. Currently, the team is testing their technique on primate limbs. According to Ott, the eventual goal for his technology is to provide a way to refit amputees with functional organs that both feel and look as close to the real deal as possible. He envisions organ donation to one day be extended to include limbs to help open up this technology to as many amputees as possible.

"We're focusing on the forearm and hand to use it as a model system and proof of principle," Ott said. "But the techniques would apply equally to legs, arms, and other extremities."

However, the biolimb isn’t the only new medical innovation sparking hope of revolutionizing the lives of those who have lost body parts. Recent advances in prosthetic technologies offer amputees also offer amputees realistic mind-controlled limbs with the added bonus of not having to wait for a donor body part.

For example, “mind-controlled” technology like bionic prosthetic limbs created by Icelandic orthopedist company Ossur allow recipients to control them just as they would their own natural limbs: with thought. This is possible thanks to tiny implanted myoelectric sensors placed into a patient’s residual muscle tissue. So far, in testing recipients have gained use of their bionic limb within minutes of being fitted, and according to Ossur, the technology could be available to the public within three to five years.