Breakthrough: Frog regrows amputated leg thanks to special drug

 As a result, its amputated leg grew back after 18 months. The breakthrough offers the prospect that in the future, the method could be used to unlock the same regenerative potential in humans, to restore tissue or body parts lost to disease or injury. love.

"It's been exciting to see how our drugs of choice have helped to regenerate a near-complete limb," said Nirosha Murugan, a professor at Tufts University in Massachusetts, US. Given the fact that it only takes a brief period of drug exposure to initiate a months-long regeneration process, we can stimulate the regenerative capacity of frogs and perhaps some other animals as well."

Many organisms are able to completely regenerate limbs, including salamanders, starfish, crabs and lizards. Flatworms can even be cut into pieces and each piece then regenerates into an entirely new organism.

The human body also has the ability to regenerate. For example, the liver can recover back to its full size after being removed in half. Children can regrow their fingertips. However, in mammals, the loss of a large limb cannot be restored by any natural process. Scar tissue will quickly form to protect us from blood loss and infection, but also prevent regeneration.

In the latest study, published in the journal Science Advances, scientists amputated a frog's hind leg and wrapped the wound in a silicone cap containing a mixture of five drugs. Each drug has a different purpose, including reducing inflammation and producing collagen to prevent scar tissue from growing. In addition, the drug is also aimed at promoting the growth of new nerve fibers, blood vessels and muscles.

This experiment was repeated in dozens of frogs, and many of them significantly developed tissue. There are many animals in which a nearly fully functional leg can be reconstructed, including bone tissue and even toe-like structures at the end of the limb. The regrown limb can move and respond to touch.

During the first few days of treatment, the scientists observed the activation of molecular pathways commonly used to identify limbs in the developing embryo. They argue that adults still retain the information needed to build body structure. In theory, they could awaken this inactivity.

Michael Levin, a professor of biology at the Vannevar Bush Institute, said that covering an open wound with a liquid medium of the right mixture could provide the necessary first step towards establishing a regenerative process. The team now plans to test the method in mammals.

Bob Lanza, head of Astellas Global Regenerative Medicine, described the progress as an 'incredible achievement'.

He says the research has extremely interesting ramifications for regenerative medicine. 'Although frogs have a much greater regenerative capacity than humans, this is a very important first step. With the right combination of drugs and factors, a similar approach could promote regeneration and restore lost function in humans," Lanza said.

Cardiology professor Michael Schneider at Imperial College London, believes the finding could have applications in other regenerative areas, such as the ability to heal wounds after a heart attack. 'These results are very exciting for human regenerative medicine. This approach can be further refined, as well as can be applied to mammals,' he shared.