Scientists are claiming an amazing breakthrough by regrowing a man's severed finger with the aid of an experimental powder.
69 year old Lee Spievak had the end of his finger cut off by a model aeroplane's propeller but after only 4 weeks his finger had grown back, together with its fingernail and fingerprint.
For ten days Mr Spievak put a little powder on his finger.
"The second time I put it on I already could see growth. Each day it was up further. Finally it closed up and was a finger.
"It took about four weeks before it was sealed."
Now he says he has "complete feeling, complete movement."
The powder comes from the University of Pittsburgh, though in the lab Dr Stephen Badylak prefers to call it extra cellular matrix.
The process he has been pioneering over the last few years involves scraping the cells from the lining of a pig's bladder.
The remaining tissue is then placed into acid, "cleaned" of all cells, and dried out before being turned into sheets, or a powder.
When the extra cellular matrix is put on a wound, scientists believe it stimulates cells in the tissue to grow rather than scar.
If they can perfect the technique, it might mean one day they could repair not just a severed finger, but severely burnt skin, or even damaged organs.
So could limbs be re-grown? Dr Badylak is cautious, but believes the technology is potentially revolutionary.
"I think that within ten years that we will have strategies that will re-grow the bones, and promote the growth of functional tissue around those bones. And that is a major step towards eventually doing the entire limb."
Like any developing technology though there are unknowns. There are worries about encouraging cancerous growths by using the matrix, however, doctors truly believe that within this powder lies an amazing medical discovery.