A cocktail of drugs allows frogs to regrow their amputated limbs

For millions of people who have lost their legs and arms for different reasons, such as diabetes or trauma, the possibility of regaining function through natural regeneration is still out of reach. This is still the stuff of salamanders, starfish, crabs or lizards.

Now the scientists of tufts university (USA) and the Wyss Institute of the Harvard University came a little closer to that goal than regenerative medicine thanks to a work published in the magazine Advances in Science.

The researchers managed to grow the amputated legs of African clawed frogs (xenopus laevis), incapable by nature of regenerating their limbs, through a combination of five drugs applied through a silicone stopper that sealed the stump for just 24 hours.

After this brief treatment, the development of the legs occurred during the next 18 monthsuntil the limb was fully and almost functionally restored.

A silicone plug to close the stumps

To achieve its objective, the Nirosha Muruganfrom the Biology department at Tufts University, designed a bioreactor called ‘BioDome‘, similar to a silicone stopper, composed of a silk protein gel loaded with cocktail five drugs cell regeneration promoters (1,4 –DPCA, BNDF, retinoic acid, among others).

Each of the drugs served a different purpose, as reduce inflammationinhibit the production of collagen that would cause scarring and encourage the growth of new nerve fibers, blood vessels s muscles.

That a brief exposure to drugs starts a months-long regeneration process suggests that frogs, and perhaps other animals, may have latent regenerative abilities that can be activated.

Nirosha Murugan, Tufts University

“It’s exciting to see that the drugs we selected helped create an almost complete limb,” says Murugan, a researcher affiliated with the Allen Discovery Center in Tufts and the paper’s first author.

Scientists worked with 115 female amputees of this frog species and divided them into three groups: one control, one with just the bioreactor and a third with the bioreactor loaded with the drug cocktail. After 24 hours, the gel was removed and the team studied limb regeneration over 18 months.

“The fact that only one brief exposure The use of drugs to initiate a months-long process of regeneration suggests that frogs, and perhaps other animals, may have latent regenerative capacities that can be activated”, comments the scientist.

a promising path

Until now, this work has focused on animals with the capacity for natural regeneration, such as the axolotl (mexican ambystoma), however, the results of this new study propose a way to start the recovery process in animals that are unable to develop an amputated limb on their own, such as frogs.

This also implies a therapeutic route promising to study limb regeneration in human beingsbut “it is unclear, from a biomedical perspective, whether the size of a human limb would affect the feasibility of endogenous regeneration,” the authors note.

In this case, people can close the wounds with the growth of new tissue, and our livers have a remarkable ability to regenerate back to normal size after a 50% loss.

But the loss of a large and structurally complex member, such as a arm or one leg, cannot be restored by any natural regeneration process in humans or mammals. In fact, we tend to cover larger lesions with an amorphous mass of scar tissue, which protects them from further blood loss and infection and prevents growth.

Therefore, the regeneration of muscles, bones and nerves (morphogenesis) of an amputated limb has always been considered Historic mark achieve in biomedicine, and works like this propose new and promising avenues of research.

In this sense, although the results are quite encouraging, the researchers emphasize the need to start new studies, changing the variables of the initial work. “This research represents a very interesting starting point to start similar experiments in mammals”, they conclude.

Source: SYNCHRONIZE

Rights: Creative Commons.