Jump into Regeneration
Regeneration is one of the most important abilities of the body. In humans, it manifests itself in wound healing, restoration of damaged skin, but the human body is not able to restore the lost limbs. But many animals have gone much further than regrowing missing legs: planarians and sea cucumbers can rebuild their bodies from a tiny particle. A popular model object in developmental biology, Xenopus laevis, or smooth spur frog, can regenerate lost limbs, being a tadpole and a frog, but as the frog matures, this ability is lost.
Progesterone is a neurosteroid, a potentially promising stimulator of peripheral nerve regeneration. It has previously been shown that progesterone is able to modulate the immune response, accelerating the healing of damage, as well as stimulate the re-growth of bone and blood vessels.
A group of scientists led by biologists and engineers from Tufts University amputated the hind limbs of adult Xenopus laevis and observed the wound healing. To start the regeneration processes, they used progesterone, which was continuously supplied to the wound surface with the help of a bioreactor during the first 24 hours after amputation. A hydrogel based on silk proteins was placed in the device and applied directly to the wound surface, which allowed progesterone molecules to constantly penetrate to the amputation site. A progesterone-free hydrogel was used as a control, and wound healing was also considered without any regeneration stimulants or other interventions.
As a result, a month after amputation, animals wearing a bioreactor with progesterone had the formation of a differentiated paddle–like structure at the site of the amputated limb - this structure is shown on the right in the figure. In the control group, as well as in the group where a bioreactor without progesterone was used, a cartilaginous spike formed in place of the amputated limb – it is shown in the figure on the left.
In addition to the fact that the paddle-like structure is morphologically more complex and closer in structure to the original limb than the cartilaginous thorn, the animal uses this type of regenerate for active movement almost on a par with the original limb.
Scientists believe that their research can become a starting point in the development of "regeneration cocktails" – mixtures of substances that can trigger full-fledged regeneration in various animals.
Article by Rincon et al. Brief Local Application of Progesterone via a Wearable Bioreactor Induces Long-Term Regenerative Response in Adult Xenopus Hindlimb published in Cell Reports.
Anastasia Poznyak, portal "Eternal Youth" http://vechnayamolodost.ru / based on Tufts University: Regeneration science takes a leap forward.