Content to pass away the millennia hidden among the damp, dark places of the world, this species of amphibian is an unlikely addition to Pluck’s List of Marvels. It’s not the fastest animal, nor the smartest, and few would classify its ability to secrete large amounts of mucus as marvelous. Nevertheless, it’s timid demeanor and slimy looks belie a secret that could change the face of medicine forever.
Last decade, the advanced research arm of the Department of Defense, DARPA, spent millions of dollars to harness the only aspect of the humble salamander that can inspire jealousy: its ability to grow back entire limbs.
Those who paid attention in third grade biology will remember that the salamander has a peculiar defense mechanism. To confuse a striking predator, the salamander leaves behind its still squirming tail, hopefully allowing the rest of it enough time to scamper off to safety. Then, over a period of just a few weeks, the salamander is able to grow back its lost appendage, replacing it perfectly.
It’s also been known to similarly regenerate eyes, arms, and even internal organs. It’s the only vertebrate that has this regenerative capability.
But according to researchers at the University of Massachusetts who received a $1.2 million grant from DARPA in 2006, humans may be able to replicate the salamander’s regenerative abilities through changing the foundation of our healing process. Mammals, including humans, form scar tissue when injured, while salamanders form blastema, “a large pool of progenitor cells that will specialize and grow to form the bone, muscle, cartilage, nerves and skin of the regenerated limb.”
By exploring ways to generate blastema in humans, DARPA hopes that years from now wounded soldiers will be able to grow back lost limbs and body parts when they return from the battle field. One can easily imagine analogous benefits for civilians as well.
But to the weekend warriors amongst us, please hold off from starting any sword juggling leagues just yet. While DARPA’s efforts moved into Phase II in 2009, it’s still far from certain that there will be any pay off, and, at best, practical benefits are still many years away.
However, if by some miracle the nerds over at DARPA pull this one off, the salamander will be the toast of the town. You heard it here first.