Pig bladders help wounded humans regrow damaged muscle, scientists say

They had each lost slabs of muscle to bomb blasts or other physical traumas, then struggled to regain even partial function of their mangled legs. Some even considered amputation.

After exhausting all conventional treatments, the five men volunteered for an experimental and seemingly outlandish surgical procedure aimed at spurring new muscle growth: They had swaths of chemically treated pig’s bladder sewn to their healthy muscle and left to decay.