Rejuvenation

Rejuvenation is a medical discipline focused on the practical reversal of the aging process.^[1]

Rejuvenation is distinct from

In some religions, people were to be rejuvenated after death prior to placing them in heaven.

The stories continued well into the 16th century. The Spanish explorer

Rejuvenation technology and its effects on individuals and society have long been a subject of science fiction. The Misspent Youth and Commonwealth Saga by Peter F. Hamilton are among the most well known examples of this, dealing with the short- and long-term effects of a near perfect 80-year-old to 20-year-old body change with mind intact. The less perfect rejuvenation featured in the Mars trilogy by Kim Stanley Robinson results in long-term memory loss and sheer boredom that comes with extreme age. The post-mortal characters in the Revelation Space series have long-term or essentially infinite lifespans, and sheer boredom induces them to undertake activities of extreme risk.

Modern developments

Most attempts at genetic repair have traditionally involved the use of a retrovirus to insert a new gene into a random position on a chromosome. But by attaching zinc fingers (which determine where transcription factors bind) to endonucleases (which break DNA strands), homologous recombination can be induced to correct and replace defective (or undesired) DNA sequences. The first applications of this technology are to isolate stem cells from the bone marrow of patients having blood disease mutations, to correct those mutations in laboratory dishes using zinc finger endonucleases and to transplant the stem cells back into the patients.^[12] More recent efforts leverage CRISPR-Cas systems or adeno-associated viruses (AAVs).

Enhanced DNA repair has been proposed as a potential rejuvenation strategy.^[13]

Stem cell regenerative medicine uses three different strategies:

1. Implantation of
   tissue
   structure
2. Implantation of stem cells into a
   tissue scaffold
   that guides restoration
3. Induction of residual cells of a tissue structure to regenerate the necessary body part

A

There are also, as commonly found throughout history, many fake rejuvenation products that have been shown to be ineffective. Chief among these are powders, sprays, gels, and homeopathic substances that claim to contain growth hormones. Authentic growth hormones are only effective when injected, mainly due to the fact that the 191-amino acid protein is too large to be absorbed through the mucous membranes, and would be broken up in the stomach if swallowed.

The

The biomedical

1. Cell loss can be repaired (reversed) just by suitable
   stem cells
   .
2. Senescent cells can be removed by activating the immune system against them. Or they can be destroyed by gene therapy to introduce "suicide genes" that only kill senescent cells.
3. Protein cross-linking can largely be reversed by drugs that break the links. But to break some of the cross-links we may need to develop enzymatic methods.
4. immune
   cells to "eat" the garbage.
5. For intracellular junk we need to introduce new enzymes, possibly enzymes from soil bacteria, that can degrade the junk (lipofuscin) that our own natural enzymes cannot degrade.
6. For
   mitochondria. A copy of the mitochondrial DNA located in the nucleus will be better protected from free radicals, and there will be better DNA repair when damage occurs. All mitochondrial proteins
   would then be imported into the mitochondria.
7. For
   stem cells
   we would introduce new stem cells every decade or so.