When Lee Spievack sliced off the tip of his finger, his brother Alan, a medical research scientist, sent him a special powder and told him to sprinkle it on the wound. In four weeks, the fingertip grew back completely.
That powder was a substance called extracellular matrix, a mix of protein and connective tissue surgeons use to repair tendons. It signals the body to start the process of tissue regrowth, and holds some of the secrets behind the emerging new science of regenerative medicine.
Many scientists believe that every tissue in the body has cells which are capable of regeneration, and the key is to find enough of those cells and direct them to grow. At least in theory, this process could be used to regrow limbs, organs, and other body parts.
* CBS News March 22, 2008