While watching tv I saw a show that featured this little boy whose finger was chopped off by a door, and when he was taken to the hospital the doctor used a drug called pixie dust to grow his finger back! There was a bit of a debate as to whether or not the powder actually grew back the boy’s finger, but there is a powder out there and it’s being used to grow tissue back!
I did some looking on the internet after hearing this and found this article http://www.dailymail.co.uk/sciencetech/article-563099/The-amazing-pixie-dust-pigs-bladder-regrew-severed-finger-FOUR-weeks.html that talks about a man whose finger was cut off in a model airplane accident, but was then regrown with this pixie dust. Pixie dust is made out of pig bladders, and was actually used to regrow human bladders at one point. Check out the article for more info. This is a picture from the website.
Apparently Pixie Dust is also being used on some of the soldiers in Afghanistan as well article here.