On Jan. 26, 2022, scientists at Tufts and Harvard Universityﾒs Wyss Institute reported they were able to trigger regrowth of a lost leg using a five-drug cocktail applied in a silicone wearable bioreactor dome that seals in the elixir over the stump for just 24 hours. That brief treatment sets in motion an 18-month period of regrowth that restores a functional leg. The study was published in the journal Science Advances.