Small bioreactor gave frogs the ability to regrow lost limbs

Some amphibians have an amazing ability to grow lost legs. And there are those who use this property only in childhood - then the mechanism of regeneration in their body mercilessly degrades. The private Tufts University (USA) asked how it works and created a mobile device to stimulate regenerative processes.

The subject of research by scientists has become an African clawed frog, which in the life stages of a tadpole and a young frog easily grows severed legs. Becoming an adult, she loses this ability - instead of a functional limb, a useless cartilaginous process grows. The reason, according to a team of scientists led by Celia Herrera-Ricon, is the degradation of "control points". That is, the new tissue grows, but the nodes responsible for the process are "dormant" and therefore primitive cartilage is obtained.

Cartilage (left), regenerated limb (right)

To "wake up" this mechanism, scientists have designed a portable bioreactor that is attached directly to the wound, in place of the frog's amputated leg. The silk hydrogel isolates this area and transports the progesterone directly to the cells. This steroid actively affects the bioelectric state of cells when passing through membranes, stimulates their activity. And it has already proven itself well as a catalyst for the regeneration of nerves and blood vessels.

In the course of the experiment, the constant replenishment of the wound with steroid caused the rapid growth of cells in it. And as a result, instead of useless cartilage, something paddle-like has grown, which, although not a full-fledged limb, already has signs of evolutionary influence, the use of the DNA code. Scientists admit that they were acting at random and now plan to work out in detail where the "control points" are located, and how best to influence them to launch a long-term regeneration program. It is quite possible that this work will make it possible to find the necessary "control points" in the human body.