A new device helps frogs regrow working legs after an amputation
The treatment spurred limb growth over 18 months
![Adult African clawed frog](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2022/01/012622_cw_froglegs_feat.jpg?fit=1030%2C580&ssl=1)
Adult African clawed frogs can’t fully regenerate amputated body parts on their own. But a device holding a chemical cocktail at the wound site coaxed some to regrow useful limbs.
Brian Gratwicke/Flickr (CC BY 2.0)
The cells of adult frogs seem to remember how to regrow lost legs, and a new chemical kick starter helps them hop to it.
Scientists have been seeking ways to spur the body to regrow limbs to help people that have undergone an amputation (SN: 6/12/13). Like adult humans, fully grown frogs have a limited ability to replace lost body parts. But a new treatment — a device that delivers a drug cocktail — jump-starts and improves limb regeneration after amputation in frogs, researchers report in the Jan. 26 Science Advances.
“The cells of the frog already know how to make frog legs,” having done so when the animal was a developing embryo, says Michael Levin, a developmental biologist at Tufts University in Medford, Mass. “Our goal is to figure out how to convince them to do it again.”
Levin’s team amputated the right back legs of 115 adult African clawed frogs (Xenopus laevis) at the knee. Roughly one-third of those frogs received “BioDomes,” silicone sleeves that cover the wound. To another third of the frogs, researchers attached BioDomes holding a silk-based gel that contained five chemicals, including a growth hormone, a nerve growth promoter and an anti-inflammatory substance. The BioDomes stayed on for 24 hours and then were removed from the frogs’ legs. The remaining third didn’t receive any treatments before being placed back in their tanks.
![silicone sleeve BioDome](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2022/01/012622_cw_froglegs_inline1.jpg?resize=680%2C382&ssl=1)
In animals that received the drug cocktail, “around the four-month mark, we started to see a slight difference in the leg shape,” says Nirosha Murugan, a cancer biologist now at Algoma University in Sault Ste. Marie, Canada. “With time, that bud … started to take shape into a whole leg.”
After 18 months, the frogs that received the chemicals had regrown the limbs and had nubs where toes would typically grow. The amputees kicked, stood and pushed off the walls of their tanks using their regrown legs, Levin says.