Navigation Links
Cryostasis (clathrate hydrates)


Cryostasis is the reversible cryopreservation of live biological objects.

Cryostasis is not cryonics. Cryostasis is not hibernation. Unlike cryostasis, cryonics is a practice of cryopreservation of legally dead people and pets.

Cryostasis was a plot in many famous science fiction novels and movies. At present, there is no any effective reversible cryopreservation procedure for live humans and mammals.

The new technology of cryostasis for biological objects using clathrate forming substances under high pressure can be promissing.[1] [2]

Living tissues cooled below the freezing point of water are damaged by the dehydration of the cells as ice is formed between the cells. The mechanism of freezing damage in living biological tissues has been elucidated by Renfret (1968) (Renfret A.P. Cryobiology: some fundamentals in surgical context. In: Cryosurgery. Rand R.W., Rinfret A.P., von Lode H., Eds. Springfield, IL: Charles C. Thomas, 1968) and by Mazur (1984): ice formation begins in the intercellular spaces.[3] The vapor pressure of the ice is lower than the vapor pressure of the solute water in the surrounding cells and as heat is removed at the freezing point of the solutions, the ice crystals grow between the cells, extracting water from them.

As the ice crystals grow, the volume of the cells shrinks, and the cells are crushed between the ice crystals. Additionally, as the cells shrink, the solutes inside the cells are concentrated in the remaining water, increasing the intracellular ionic strength and interfering with the organization of the proteins and other organized intercellular structures. Eventually, the solute concentration inside the cells reaches the eutectic and freezes. The final state of frozen tissues is pure ice in the former extracellular spaces, and inside the cell membranes a mixture of concentrated cellular components in ice and bound water. In general, this process is not reversible to the point of restoring the tissues to life, although there are occasional exceptions observed in nature (vitrifying polyols (i.e., insects, amphibians), thermal hysteresis proteins (insects, fish).[4] [5]

Clathrate hydrates are a class of solids in which gas molecules occupy "cages" made up of hydrogen-bonded water molecules. These "cages" are unstable when empty, collapsing into conventional ice crystal structure, but they are stabilised by the inclusion of the gas molecule within them. Most low molecular weight gases (including O2, N2, CO2, CH4, H2S, Ar, Kr, and Xe) will form a hydrate under some pressure-temperature conditions.[6]

Live biological tissues can be saturated with the clathrate-forming gas(es) by diffusion or perfusion at the appropriate pressure in the range 1–50 bars at a temperature above clathrate-forming temperature. After saturation, the biological tissue is cooled, first below the clathrate-forming temperature, but above the freezing point of water, then to a temperature where the clatharate is metastable at ambient pressure, and the pressure allowed to go to ambient. The "biological tissue" is then gradually cooled down to some appropriate temperature at normal atmospheric pressure and stored an indefinite time.

The method protects biological tissues by retention of water inside the cells by clathrate formation of the water with the introduced gases, limiting the formation of ice outside the cells.

See also

References

External links


'"/>


(Date:4/18/2014)... Medicine scientists could lead to potential new treatments for ... scleroderma. , Fibrosis, or scarring, is a hallmark ... and lungs can lead to serious organ damage and, ... therapeutic options centers on findings made by Swati Bhattacharyya, ... role that a specific protein plays in promoting fibrosis. ...
(Date:4/17/2014)... chronic inflammation in non-cancerous prostate tissue may have nearly ... those with no inflammation, according to results of a ... Kimmel Cancer Center. , The link between persistent inflammation ... high-grade prostate cancer those with a Gleason score ... the most aggressive and rapidly growing prostate cancers. , ...
(Date:4/17/2014)... have identified new pain relief targets that could ... BBSRC-funded researchers at King,s College London made the ... in the periphery of the body. , Dr ... identifying mechanisms underlying pain generation and our findings ... side effects." , One potential side effect of ...
(Date:4/17/2014)... a study published today in PLOS Pathogens , ... malaria is common can mount an immune response to ... avoid repeated bouts of high fever and illness and ... bloodstream. The findings may help researchers develop future interventions ... malaria parasite. , Each year, approximately 200 million cases ...
(Date:4/17/2014)... University of California, San Diego School of Medicine report ... suffered a recent major loss are more likely to ... The study is published in this month,s issue of ... Because compassionate behaviors are associated with better health and ... into ways to improve the outcomes of individuals whose ...
Breaking Medicine News(10 mins):Health News:New clues on tissue scarring in scleroderma 2Health News:Chronic inflammation linked to 'high-grade' prostate cancer 2Health News:Chronic inflammation linked to 'high-grade' prostate cancer 3Health News:New pain relief targets discovered 2Health News:Study sheds light on how the immune system protects children from malaria 2Health News:The ilk of human kindness 2
... film "Being Cyrus" coming up, the number of films// in ... sexual side has shot up once more. ,The made-in-Mumbai ... is attracted towards Cyrus, essayed by Saif Ali Khan. The ... the exception of a handful of movies like "Freaky Chakra", ...
... tobacco industry battle is// the health care costs. ... into high gear within two years. This info was provided ... said, "This will unfold in a stepwise fashion over the ... position to work with our colleagues in British Columbia and ...
... reported in Egypt, the most populous North African country. Laboratory ... died as a consequence of the highly pathogenic H5N1 strain ... in Qalyubiya, some 40 km north of here, died early ... treated for flu-like symptoms, the health ministry said in a ...
... easing their emotional pain by taking Oxycontin, a prescription painkiller. ... heroin as a cheaper option. // Michaud, now 18 ... getting addicted to prescription drugs. Teenagers are increasingly experimenting with ... online or taken from medicine cabinets. , Health ...
... the NHS on April 1. Dentists in England and Wales ... April 1st. // Several Cumbrian practices have already opted out. ... when leaving the NHS. ,But now due to ... days notice. The North Cumbria Primary Care Trusts (PCTs) cannot ...
... good news but there is a silver lining. Those children ... onset to develop kidney failure in adulthood.// ,This ... journal Diabetes Care. ,Dr. Maria Svensson, of Umea University ... from two nationwide registers, which include 12,032 cases of childhood ...
Cached Medicine News:Health News:Needed, more space for women's sexual identity on marquees 2Health News:Needed, more space for women's sexual identity on marquees 3Health News:Needed, more space for women's sexual identity on marquees 4Health News:New Generation Teenagers Addiction to Prescription Drugs 2
Other medicine definitionOther Tags