Regeneration a possibility?

The advancement in medical treatments and standards of livings has increased human lifespan by more than double compared to 1.5 million years ago. But is immortality achievable? If you can live to eternity, what would you trade for? Perhaps becoming better human with as many good manners defined by society as possible as opposed to unhealthy lifestyles to forgo the birth of next generations which includes potential innovations and deal with the problems of aging population growth but will the immortal people commit to this?

So can we achieve this infinite lifespan? In human, we have very limited capacity for regeneration because of perhaps limited number of stem cells. What about other creatures? Jellyfish was one of our ancestors which first appeared approximately 540 million years ago during the Cambrian period. A type of jellyfish named Turritopsis nutricula is immortal through a process called transdifferentiation adopted in its cell cycle. American Lobsters or Homarus americanus as a crustacean has very long lifespan if it does not suffer diseases or injuries or caught by humans for food. Apart from that, the lobsters become brawnier and increase in its reproduction after every time they rejuvenate themselves. Being formed just after Jellyfish according to the Tree of Life, Starfish possess excellent limb regenerative ability. First existed 400-300 million years ago, salamanders (amphibian) and geckos (reptile) also have great limb regeneration. Since they are our ancestors, they are related to us but due to divergent evolution to adapt to different habitats, we evolve into different appearances, structures and functions like we are today. Majority of these species live in wet or ocean environment, while we live on land, breath in O₂ as part of our respiration. There also seems to be a trade-off between reproduction and survival. Maybe somehow during revolution, we have lost the regenerative capacity to trade for sexual reproduction which enhances the gene pool hence diversity in the population.

American Lobsters – sharp and strong claws can cut the metal Coke can in half

Starfish - limb regeneration 

So is there similarity between us and these creatures? In 1962, a scientist named Sir John B. Gurdon transferred the nucleus of frog differentiated epithelial cells into an enucleated egg which then generated a fully mature tadpole. He then proved that every cell in the same body has the same genetics. Taking inspiration from this genius experiment on frog which is an amphibian, a doctor named Shinya Tamanaka dedifferentiated human fibroblasts into its pluripotent state.  Despite the current debate on whether this induced pluripotent stem cells are similar to embryonic stem cells, we have learnt that nature has taught us many things from disease treatments such as penicillin (from the mold formed by Penicillium fungi) to today ground-breaking discovery about cellular differentiation which is a reversible process. This might mean wherever there is life, there is scope for regeneration but to different extent, and human beings are trying to figure out how to obtain the complete regeneration process to permanently repair tissues, organs and body parts. 

Maybe our immunity holds the key. According to Australian Regenerative Medicine Institute at Monash University, macrophages a special type of cells which can phagocytose cellular debris, pathogens or dead cells plays a part in initiating a scar-free regeneration outcome in salamander. 

Many doubts still remain, but we turn our attention towards the 3D printers for now. By using biomaterials in the printers, so far 3D structural scaffold of five organs which are the ears, kidneys, blood vessels, skin grafts and bones have been designed and printed. What would you envisage in the far future? Possibly limb regeneration like Dr. Curt Connors who turned himself into the Lizard in Spiderman with the genetic cocktail or Khan according to Star Trek sci-fi world, he was genetically modified to be superior in regeneration.