Human Regeneration and Regrowing Body Parts

This world of ours has abundance of life-forms, many of whom we’re just discovering. Among those that we know of, there is far less of them that we understand. We have just scratched the surface of innumerable possibilities this biodiversity offers us in terms of exploiting millions of years of nature’s bioengineering to develop new technologies and improve existing ones. Some of the most ground-braking inventions humans have materialized were inspired by nature. From spider silk turned into medical tape that can be removed off the wound without any damage to the tissue underneath, trough superstrong adhesive mimicking gecko foot-hair, to advanced robotic design adapted for space explorations, humans have relied on nature to provide us with guidelines for mastering our environment and overcoming our limitations.
All these inventions are valuable, but now we can go even further in terms of adopting some of the nature’s solutions to improve our frail bodies and skip millions of years of evolution of our species. We have already come to terms with using modifications to our bodies to compensate for some congenital or acquired defects. Most scientists agree that the future of medicine lies in biomedicine and nanotechnology.

Lizards, when threatened by predators, reject their tail as a means of diversion. They have the ability to regrow new ones. Frogs and Triton have similar regenerative capacities which, it was believed, are not bestowed upon people.

But, apart from some well-documented cases where young children were able to regrow fingers severed in accidents, there are some other cases where adults, like a woman named Deepa Kulkarni, who lost her fingertip in an accident back in 2010 could regenerate it with the help of medications such as MatriStem manufactured by the company called Acell. This is a new treatment in which the damaged part of the body is coated with a powder made of pig’s bladder that stimulates the growth of a bone and surrounding tissue. Workings on mice, frogs and lizards showed that such treatment can be applied to humans. Although many have called such stories ‘junk science’, there is in fact some evidence that our fingernail contains stem cells called ‘Wnts’ which produce chemicals capable of stimulating renewal of bone and flesh.

According to The Telegraph, with the discovery of a special gene, called p21, regrowing amputated limbs, broken spines, and even damaged brains might become a reality one day. Researchers at the Wistar Institute, Philadelphia, found that the gene p21 apparently blocks the ability of mammalian for a renewal of body parts, which some amphibians still have. Through the evolution, bodies of most spices adapted the healing process in which wounded tissue heals by forming a scar, while some amphibian resort to different strategy by regrowing chopped off limbs from the stem.

Turning off the p21 gene in mice showed that regenerative process may be switched on, thus enabling their cells to act like embryonic stem cells, recreating body parts, like ears, for example. In theory, the same processes can be applied to humans. p21 has a very important role in our bodies, since it blocks reproduction of damaged cells and prevents the development of cancer and similar diseases, so if any therapy implying turning p21 off should be applied, it has to be done locally, and on a temporary basis.

Most of the work in the domain of regenerative medicine revolves around stem cell research. Scientists have high hopes for this field, having achieved some significant results so far, like artificially grown windpipe, liver buds and brain organoids.

Michael Levin, director of Tufts University’s Center for Regenerative and Developmental Biology, has a quite different approach to human regeneration. He believes that by manipulating electrical signals transmitted among our cells, he might trigger targeted reproduction of cells into desired organs. By figuring out how to read those signals exchanged by our body’s cells, we could instruct them to reproduce as a differential part of a specific organ.
It might be long before scientists discover a way for humans to trick nature and generate process leading to the regrowth of body parts, but the temptation to do so is irresistible. This entails undermining promise of healthier and longer lives for future generations of humans.