Is it possible to regrow a frog’s lost leg?
Researchers have come a step closer to the goal of regenerative medicine by successfully triggering regrowth of a lost leg in a frog using a five-drug cocktail contained in a silk protein gel and kept in place over the stump for a day. That brief treatment sets in motion an 18-month period of regrowth that restores a functional leg. The research was carried out by scientists at Tufts University and Harvard University's Wyss Institute (Science Advances).
The researchers triggered the regenerative process in African clawed frogs by enclosing the wound in a silicone cap, which they call a BioDome, containing a silk protein gel loaded with the five-drug cocktail.
Each drug fulfilled a different purpose.. The combination and the bioreactor provided a local environment and signals that tipped the scales away from the natural tendency to close off the stump, and toward the regenerative process, according to a press release from Tufts University.
The researchers observed dramatic growth of tissue in many of the treated frogs, re-creating an almost fully functional leg. The new limbs had bone structure extended with features similar to a natural limb's bone structure, a richer complement of internal tissues (including neurons), and several "toes" grew from the end of the limb, although without the support of underlying bone.
The regrown limb moved and responded to stimuli such as a touch from a stiff fibre, and the frogs were able to make use of it for swimming through water, moving much like a normal frog would.
