Editing Cryonics (section)

==Obstacles to success==
=== Preservation damage ===
Medical laboratories have long used cryopreservation to maintain animal cells, human embryos, and even some organized tissues, for periods as long as three decades.<ref>{{cite journal|vauthors=Crippen DW, Reis RJ, Risco R, Vita N|date=October 2015|title=The Science Surrounding Cryonics |url=https://www.technologyreview.com/2015/10/19/109714/the-science-surrounding-cryonics/|journal=MIT Technology Review}}</ref> But recovering large animals and organs from a frozen state is not considered possible now.<ref>{{cite journal|author=Smith Audrey U |year=1957 |title=Problems in the Resuscitation of Mammals from Body Temperatures Below 0&nbsp;°C|journal=Proceedings of the Royal Society of London. Series B, Biological Sciences|volume=147|issue=929|pages=533–44|bibcode=1957RSPSB.147..533S|doi=10.1098/rspb.1957.0077|jstor=83173|pmid=13494469|s2cid=40568140}}</ref><ref name="Fahy GM, Wowk B, Pagotan R 167–75" /><ref>{{cite journal|vauthors=Fahy GM, Wowk B, Wu J|year=2006|title=Cryopreservation of complex systems: the missing link in the regenerative medicine supply chain|url=http://www.21cm.com/articles/Missing_Link.pdf|journal=Rejuvenation Research |volume=9 |issue=2 |pages=279–291 |citeseerx=10.1.1.539.7419|doi=10.1089/rej.2006.9.279|pmid=16706656|access-date=2017-10-24|archive-date=2017-10-25|archive-url=https://web.archive.org/web/20171025022108/http://www.21cm.com/articles/Missing_Link.pdf|url-status=live}}</ref> Large vitrified organs tend to develop fractures during cooling,<ref>{{cite journal |vauthors=Fahy GM, Saur J, Williams RJ |title=Physical problems with the vitrification of large biological systems|journal=Cryobiology |volume=27 |issue=5 |pages=492–510 |date=October 1990 |pmid=2249453 |doi=10.1016/0011-2240(90)90038-6}}</ref> a problem worsened by the large tissue masses and very low temperatures of cryonics.<ref>{{cite magazine |author=Wowk B |title=Systems for Intermediate Temperature Storage for Fracture Reduction and Avoidance| magazine =Cryonics| pages = 7–13| year=2011| volume =2011| issue =3| publisher = Alcor Life Extension Foundation| issn=1054-4305}}</ref> Without cryoprotectants, cell shrinkage and high salt concentrations during freezing usually prevent frozen cells from functioning again after thawing. Ice crystals can also disrupt connections between cells that are necessary for organs to function.<ref>{{cite journal|vauthors=Fahy GM, Levy DI, Ali SE|date=June 1987|title=Some Emerging Principles Underlying the Physical Properties, Biological Actions, and Utility of Vitrification Solutions|journal=Cryobiology|volume=24|issue=3|pages=196–213|doi=10.1016/0011-2240(87)90023-X|pmid=3595164}}</ref>

Some cryonics organizations use vitrification without a [[fixation (histology)|chemical fixation]] step,<ref>{{cite web |title=Alcor Position Statement on Brain Preservation Prize |publisher=Alcor Life Extension Foundation |date=2016-02-12 |url=http://www.alcor.org/blog/alcor-position-statement-on-brain-preservation-foundation-prize/ |access-date=2016-03-20 |archive-date=2016-02-15 |archive-url=https://web.archive.org/web/20160215230517/http://www.alcor.org/blog/alcor-position-statement-on-brain-preservation-foundation-prize/ |url-status=live}}</ref> sacrificing some structural preservation quality for less damage at the molecular level. Some scientists, like João Pedro Magalhães, have questioned whether using a deadly chemical for fixation eliminates the possibility of biological revival, making chemical fixation unsuitable for cryonics.<ref>{{cite web |title=Mammal brain frozen and thawed out perfectly for first time |url=https://www.newscientist.com/article/2077140-mammal-brain-frozen-and-thawed-out-perfectly-for-first-time/ |access-date=2016-06-06 |work=[[New Scientist]] |archive-date=2016-06-16 |archive-url=https://web.archive.org/web/20160616185949/https://www.newscientist.com/article/2077140-mammal-brain-frozen-and-thawed-out-perfectly-for-first-time/ |url-status=live}}</ref>

Outside of cryonics firms and cryonics-linked interest groups, many scientists are very skeptical about cryonics methods. [[Cryobiologist]] Dayong Gao has said, "we simply don't know if [subjects have] been damaged to the point where they've 'died' during vitrification because the subjects are now inside liquid nitrogen canisters." Based on experience with organ transplants, biochemist Ken Storey argues that "even if you only wanted to preserve the brain, it has dozens of different areas which would need to be cryopreserved using different protocols".<ref name="bbc frozen" />

===Revival===
Revival would require repairing damage from lack of oxygen, cryoprotectant toxicity, thermal stress (fracturing), and freezing in tissues that do not successfully vitrify, followed by reversing the cause of death. In many cases, extensive [[Regeneration (biology)|tissue regeneration]] would be necessary.<ref>{{cite journal |last1=Karow |first1=Armand |last2=Webb |first2=Watts |title=Tissue Freezing: A theory for injury and survival |journal=Cryobiology |volume=2 |issue=3 |pages=99–108 |date=1965 |pmid=5860601 |doi=10.1016/s0011-2240(65)80094-3}}</ref> This revival technology remains speculative.<ref name="guardian cold facts" />

===Legal issues===
Historically, people had little control over how their bodies were treated after death, as religion held jurisdiction over the matter.<ref name="trust">{{cite book |last1=Dukeminier |first1=Jesse |last2=Sitkoff |first2=Robert |date=2013 |title=Wills, Trusts, and Estates |publisher=Wolters Kluwer Law & Business in New York |page=507 |isbn=978-1-4548-2457-2}}</ref> But secular courts began to exercise jurisdiction over corpses and use discretion in carrying out deceased people's wishes.<ref name="trust" /> Most countries legally treat preserved bodies as [[deceased]] persons because of laws that forbid vitrifying someone who is medically alive.<ref name="guardian frozen in time">{{cite web|url=https://www.theguardian.com/technology/2008/feb/14/research.cryonics|title=Patients who are frozen in time|website=[[TheGuardian.com]]|date=14 February 2008|access-date=12 October 2020|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512202813/https://www.theguardian.com/technology/2008/feb/14/research.cryonics|url-status=live}}</ref> In France, cryonics is not considered a legal mode of body disposal;<ref>{{cite web |url=http://www.leparticulier.fr/jcms/c_101664/conseil-d-etat-du-06/01/2006-n-260307-cryogenisation-interdiction |title=Conseil d'État du 06/01/2006, n° 260307: Cryogénisation – interdiction |access-date=2014-01-07 |archive-url=https://web.archive.org/web/20140107144511/http://www.leparticulier.fr/jcms/c_101664/conseil-d-etat-du-06/01/2006-n-260307-cryogenisation-interdiction |archive-date=2014-01-07 |url-status=dead}}</ref> only burial, cremation, and formal [[body donation]] to science are allowed, though bodies may legally be shipped to other countries for cryonic freezing.<ref>{{cite news|last=Chrisafis|first=Angelique|title=Freezer failure ends couple's hopes of life after death|url=https://www.theguardian.com/science/2006/mar/17/france.internationalnews|access-date=8 January 2014|newspaper=[[The Guardian]]|date=16 March 2006|archive-date=8 January 2014|archive-url=https://web.archive.org/web/20140108035430/http://www.theguardian.com/science/2006/mar/17/france.internationalnews |url-status=live}}</ref> As of 2015, [[British Columbia]] prohibits the sale of arrangements for cryonic body preservation.<ref>{{cite news|last=Proctor|first=Jason|title=Immortality sought through B.C. Supreme Court lawsuit|url=http://www.cbc.ca/news/canada/british-columbia/immortality-sought-through-b-c-supreme-court-lawsuit-1.3153430|access-date=21 February 2016|publisher=[[CBC News]]|date=16 July 2015|archive-date=21 February 2016|archive-url=https://web.archive.org/web/20160221125254/http://www.cbc.ca/news/canada/british-columbia/immortality-sought-through-b-c-supreme-court-lawsuit-1.3153430|url-status=live}}</ref> In Russia, cryonics falls outside both the medical industry and the funeral services industry, making it easier than in the U.S. to get hospitals and morgues to release cryonics candidates.<ref name="ft" />

In 2016, the English [[High Court of Justice|High Court]] ruled in favor of a mother's right to seek cryopreservation of her terminally ill 14-year-old daughter, as the girl wanted, contrary to the father's wishes. The decision was made on the basis that the case represented a conventional dispute over the disposal of the girl's body, although the judge urged ministers to seek "proper regulation" for the future of cryonic preservation after the hospital raised concerns about the competence and professionalism of the team that conducted the preservation procedures.<ref>{{cite news |url=https://www.bbc.co.uk/news/health-38012267 |title=Terminally ill teen won historic ruling to preserve body |date=18 November 2016 |publisher=[[BBC News]] |language=en-GB |access-date=18 November 2016 |archive-date=18 November 2016 |archive-url=https://web.archive.org/web/20161118012553/http://www.bbc.co.uk/news/health-38012267|url-status=live}}</ref> In ''[[Alcor Life Extension Foundation]] v. Richardson'', the [[Iowa Court of Appeals]] ordered the disinterment of Richardson, who was buried against his wishes, for cryopreservation.<ref name="trust" /><ref>{{cite web |title=Alcor Life Extension Foundation v. Richardson |url=http://www.leagle.com/decision/In%20IACO%2020100512306/ALCOR%20LIFE%20EXTENSION%20FOUND.%20v.%20RICHARDSON |date=2010 |publisher=785 N.W.2d 717 |access-date=2017-01-07 |archive-date=2017-01-07 |archive-url=https://web.archive.org/web/20170107171724/http://www.leagle.com/decision/In%20IACO%2020100512306/ALCOR%20LIFE%20EXTENSION%20FOUND.%20v.%20RICHARDSON |url-status=live}}</ref>

A detailed legal examination by Jochen Taupitz concludes that cryonic storage is legal in Germany for an indefinite period.<ref>{{cite book |last1=Taupitz |first1=Jochen |last2=Fuhr |first2=Günther |last3=Zwick |first3=Anna |last4=Salkic |first4=Amina |date=2013 |title=Unterbrochenes Leben? |url=https://www.bookshop.fraunhofer.de/buch/unterbrochenes-leben/240032 |location=St. Ingbert, Germany |publisher=Fraunhofer Verlag |isbn=978-3-8396-0593-6 |access-date=2018-12-26 |archive-date=2018-12-27 |archive-url=https://web.archive.org/web/20181227040823/https://www.bookshop.fraunhofer.de/buch/unterbrochenes-leben/240032 |url-status=live}}</ref>