An Ohio man completely regenerated a severed finger in only four weeks by applying a powder developed by researchers at the University of Pittsburgh.
The finger appears to have grown back completely, including the nerves, nail and even fingerprint. Spievak says that he has "complete feeling [and] movement."
The dust Spievak used was developed by Stephen Badylak and colleagues, who produce it by scraping cells out of the lining of a pig's bladder, then immersing the rest of the bladder tissue in acid. The last remnants of cells are then cleaned out, and the processed bladder is dried into a powder. According to Badylak, this powder signals cells to regrow tissue, rather than scarring as they normally would.