While the report of pig bladder powder growing back a man's finger might have been a wee bit exaggerated and/or fabricated, the science behind it is sound. In fact, doctors in Texas are using a pig-based powder, dubbed "Pixie Dust," to try to grow back a soldier's finger.
They aren't sure how well it'll work and are consistently monitoring it, but in theory the powder tricks dormant stem cells in the human body into kicking into gear, growing more of whatever body part they're touching. That means that if it's on skin, it'll grow more skin. If it's on a tendon, it'll regrow tendons. Will it be able to regrow a functioning human finger? And if so, will it work with other body parts such as internal organs? Time will tell. [CNN]