Cryobiology
Encyclopedia
Cryobiology is the branch of biology
that studies the effects of low temperature
s on living things. The word cryobiology is derived from the Greek words "cryo" = cold, "bios" = life, and "logos" = science. In practice, cryobiology is the study of biological material or systems at temperatures below normal. Materials or systems studied may include protein
s, cells
, tissues
, organs, or whole organisms. Temperatures may range from moderately hypothermic
conditions to cryogenic temperatures.
at low temperature
s.
Cryogenics
: is the branch of physics
and engineering
that studies the production and use of very low temperature
s. Cryogenics is not cryonics, although people often confuse them.
Cryonics
: is the low temperature preservation of humans and mammals with the intention of future revival. Cryonics is not part of mainstream cryobiology. Cryonics still depends heavily on speculative future technology which may or may not be invented.
Cryopreservation
: is a technology whereby cells, whole tissues, or embryos are preserved by cooling to temperatures below the freezing point of water.
s such as anti-nucleating proteins
, polyols, and glucose
to protect themselves against frost damage by sharp ice crystals. Most plants, in particular, can safely reach temperatures of −4 °C to −12 °C.
, as well as Chryseobacterium greenlandensis
and Herminiimonas glaciei
, have reportedly been revived after surviving for thousands of years frozen in ice.
Certain bacteria
, notably Pseudomonas syringae
, produce specialized proteins that serve as potent ice nucleators, which they use to force ice formation on the surface of various fruits and plants at about −2 °C. The freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria.
which allows them to survive temperatures below 0 degrees C for weeks to months.
nymphs (Periplaneta japonica) survive short periods of freezing at -6 to -8 degrees C. The red flat bark beetle (Cucujus
clavipes) can survive after being frozen to -150 C. The fungus gnat
Exechia nugatoria can survive after being frozen to -50 C, by a unique mechanism whereby ice crystals form in the body but not the head. Another freeze-tolerant beetle is Upis ceramboides. See insect winter ecology
and antifreeze protein
. Another invertebrate that is tolerant to temperatures down to -273 C is the water bear, an extremophile
.
The larvae of Haemonchus contortus
, a nematode
, can survive 44 weeks frozen at -196 C.
(Rana sylvatica), in the winter, as much as 45% of its body may freeze and turn to ice. "Ice crystals form beneath the skin and become interspersed among the body's skeletal muscles. During the freeze the frog's breathing, blood flow, and heart beat cease. Freezing is made possible by specialized proteins and glucose, which prevent intracellular freezing and dehydration." The wood frog can survive up to 11 days frozen at -4 C.
Other vertebrates that survive at body temperatures below 0 C include painted turtles (Chrysemys picta), Gray tree frog (Hyla versicolor), Box turtles (Terrapene carolina)- 48 hours at -2 C, Spring peeper
(Pseudacris crucifer), Garter snakes (Thamnophis sirtalis)- 24 hours at -1.5 C, the chorus frog
(Pseudacris triseriata), Siberian salamander
(Salamandrella keyserlingii), 24 hours at -15.3 C, Antarctic fish such as Pagothenia borchgrevinki and the European common lizard (Lacerta vivipara).
Professor Joshua Barr of the Staines Cyrobiology Laboratory in Middlesex (UK) has been carrying out experiments with British tree frogs to discover whether they also exhibit tolerance to very low temperatures in the same way as exhibited by American Tree Frogs. Thus far results have been inconclusive, however Professor Barr is optimistic about the future.
Hibernating Arctic ground squirrel
s may have abdominal temperatures as low as -2.9 C, maintaining sub-zero abdominal temperatures for more than three weeks at a time, although the temperatures at the head and neck remain at 0 C or above.
Cryobiology history can be traced back to antiquity. As early as in 2500 BC low temperatures were used in Egypt in medicine. The use of cold was recommended by Hippocrates
to stop bleeding and swelling. With the emergence of modern science
, Robert Boyle
studied the effects of low temperatures on animals.
In 1949 bull sperm
was cryopreserved
for the first time by a team of scientists led by Christopher Polge
(1926–2006). This led to a much wider use of cryopreservation
today, with many organs
, tissues
and cell
s routinely stored at low temperature
s. Large organs such as heart
s are usually stored and transported, for short times only, at cool but not freezing temperatures for transplantation
. Cell suspensions (like blood
and semen
) and thin tissue sections can sometimes be stored almost indefinitely at liquid nitrogen
temperature (cryopreservation
). Human sperm, eggs and embryo
s are routinely stored in fertility
research and treatments. Controlled-rate and slow freezing are well established techniques pioneered in the early 1970s which enabled the first human embryo frozen birth (Zoe Leyland) in 1984. Since then machines that freeze biological samples using programmable steps, or controlled rates, have been used all over the world for human, animal and cell biology – 'freezing down' a sample to better preserve it for eventual thawing, before it is deep frozen, or cryopreserved, in liquid nitrogen. Such machines are used for freezing oocytes, skin, blood products, embryo, sperm, stem cells and general tissue preservation in hospitals, veterinary practices and research labs. The number of live births from 'slow frozen' frozen embryos is some 300,000 to 400,000 or 20% of the estimated 3 million IVF births. Dr Christopher Chen, Australia, reported the world’s first pregnancy using slow frozen oocytes from a British Controlled Rate freezer in 1986.
Cryosurgery
(intended and controlled tissue destruction by ice formation) was carried out by James Arnott in 1845 in an operation on a patient with cancer
. Cryosurgery is not common.
is primarily concerned with low temperature preservation. Hypothermic
storage is typically above 0°C but below normothermic (32°C to 37°C) mammalian temperatures. Storage by cryopreservation
, on the other hand, will be in the −80°C to −196°C temperature range. Organ
s, and tissue
s are more frequently the objects of hypothermic storage, whereas single cells have been the most common objects cryopreserved.
A rule of thumb in hypothermic storage is that every 10°C reduction in temperature is accompanied by a 50% decrease in oxygen consumption
. Although hibernating animals have adapted mechanisms to avoid metabolic imbalance
s associated with hypothermia, hypothermic organs and tissues being maintained for transplantation
require special preservation solutions to counter acidosis
, depressed sodium pump
activity and increased intracellular calcium
. Special organ preservation solutions such as Viaspan
(University of Wisconsin solution), HTK
, and Celsior have
been designed for this purpose. These solutions also contain ingredients to minimize damage by free radicals
, prevent edema
, compensate for ATP
loss, etc.
Cryopreservation of cells is guided by the "Two-Factor Hypothesis" of American cryobiologist Peter Mazur, which states that excessively rapid cooling kills cells by intracellular ice formation and excessively slow cooling kills cells by either electrolyte
toxicity
or mechanical crushing. During slow cooling ice forms extracellularly, causing water to osmotically
leave cells, thereby dehydrating
them. Intracellular ice can be much more damaging than extracellular ice.
For red blood cell
s the optimum cooling rate is very rapid (nearly 100°C per second), whereas for stem cell
s the optimum cooling rate is very slow (1°C per minute). Cryoprotectant
s, such as DMSO (dimethyl sulfoxide
) and glycerol
, are used to protect cells from freezing
. A variety of cell types are protected by 10% DMSO. Cryobiologists attempt to optimize cryoprotectant concentration (minimizing both ice formation and toxicity) as well as cooling rate. Cells may be cooled at an optimum cooling rate to a temperature between −30°C and −40°C before being plunged into liquid nitrogen
.
Slow cooling methods rely on the fact that cells contain few nucleating
agents, but contain naturally-occurring vitrifying substances that can prevent ice formation in cells that have been moderately dehydrated. Some cryobiologists are seeking mixtures of cryoprotectants for full vitrification (zero ice formation) in preservation of cells, tissues and organs. Vitrification methods pose a challenge in the requirement to search for cryoprotectant mixtures that can minimize toxicity.
at -196°C for 10 years under well-controlled laboratory conditions.
Cryopreservation
in humans with regards to infertility involves preservation of embryos, sperm or oocytes via freezing. Conception, in vitro, is attempted when the sperm is thawed and introduced to the 'fresh' eggs, the frozen eggs are thawed and sperm is placed with the eggs and together they are placed back into the uterus or a frozen embryo is introduced to the uterus. Vitrification has its glitches and is not as reliable or proven as freezing fertilized sperm, eggs or embryos as traditional slow freezing methods because eggs alone are extremely sensitive to temperature. Many researchers are also freezing ovarian tissue in conjunction with the eggs in hopes that the ovarian tissue can be transplanted back into the uterus, stimulating normal ovulation cycles. In Sep 2004 Prof Donnez of Louvain in Belgium reported the first successful ovarian birth from frozen ovarian tissue. In 1997 samples of ovarian cortex were taken from a woman with Hodgkin’s lymphoma and cryo-preserved in a (Planer, UK) controlled rate freezer and then stored in liquid Nitrogen. Chemotherapy was initiated and after the patient had premature ovarian failure. In 2003, after freeze-thawing, orthotopic autotransplantation of ovarian cortical tissue was done by laparoscopy and five months after reimplantation signs indicated recovery of regular ovulatory cycles. Eleven months after re-implantation a viable intrauterine pregnancy was confirmed, which resulted in the first such live birth – a girl called Tamara.
Therapeutic hypothermia
, e.g. during heart surgery on a "cold" heart (generated by cold perfusion without any ice formation) allows for much longer operations and improves recovery rates for patients.
based. The purpose of the Society is to promote scientific research in low temperature biology, to improve scientific understanding in this field, and to disseminate and apply this knowledge to the benefit of mankind. The Society requires of all its members the highest ethical and scientific standards in the performance of their professional activities. According to the Society's bylaw
s, membership may be refused to applicants whose conduct is deemed detrimental to the Society; in 1982, the bylaws were amended explicitly to exclude "any practice or application of freezing deceased persons in the anticipation of their reanimation," over the objections of some members who were cryonicists such as Jerry Leaf
. The Society organizes an annual scientific meeting
dedicated to all aspects of low-temperature biology. This international meeting offers opportunities for presentation and discussion of the most up-to-date research in cryobiology as well as reviewing specific aspects through symposia and workshops. Members are also kept informed of news and forthcoming meetings through the Society newsletter, News Notes. The 2009-2010 President of the Society for Cryobiology is Barry J. Fuller.
The Society for Low Temperature Biology was founded in 1964 and became a Registered Charity
in 2003 with the purpose of promoting research into the effects of low temperatures on all types of organisms and their constituent cells, tissues and organs. As of 2006, the Society for Low Temperature Biology had approximately 130 (mostly British and European) members and holds at least one Annual General Meeting. The program usually includes both a symposium
on a topical subject and a session of free communications on any aspect of low temperature biology. Recent symposia have included long-term stability, preservation of aquatic organisms, cryopreservation of embryos and gamete
s, preservation of plants, low temperature microscopy
, vitrification (glass formation of aqueous systems during cooling), freeze drying
and tissue banking
. Members are informed through the Society Newsletter, which is presently published 3 times a year. The present chair (2010-2011) of the Society for Low Temperature Biology is Hugh Pritchard. A list of additional scientific societies (mostly using "applied" cryobiology) can be found here.
) is the foremost scientific publication in this area, with approximately 60 refereed contributions published each year. Articles concern any aspect of low temperature biology and medicine (e.g. freezing, freeze-drying
, hibernation, cold tolerance and adaptation, cryoprotective compounds
, medical applications of reduced temperature, cryosurgery
, hypothermia
, and perfusion of organs).
CRYO LETTERS is an independent UK based rapid communication journal which publishes papers on the effects produced by low temperatures on a wide variety of biophysical and biological processes, or studies involving low temperature techniques in the investigation of biological and ecological
topics.
CELL PRESERVATION TECHNOLOGY is a peer-reviewed quarterly scientific journal
published by Mary Ann Liebert, Inc.
dedicated to the diverse spectrum of preservation technologies including cryopreservation
, dry-state (anhydrobiosis), glassy-state and hypothermic maintenance. Cell Preservation Technology has been renamed Biopreservation and Biobanking and is the official journal of International Society for Biological and Environmental Repositories (ISBER).
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
that studies the effects of low temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
s on living things. The word cryobiology is derived from the Greek words "cryo" = cold, "bios" = life, and "logos" = science. In practice, cryobiology is the study of biological material or systems at temperatures below normal. Materials or systems studied may include protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s, cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
, tissues
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
, organs, or whole organisms. Temperatures may range from moderately hypothermic
Hypothermia
Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...
conditions to cryogenic temperatures.
Definitions/Distinctions
Cryobiology: is the study of lifeLife
Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...
at low temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
s.
Cryogenics
Cryogenics
In physics, cryogenics is the study of the production of very low temperature and the behavior of materials at those temperatures. A person who studies elements under extremely cold temperature is called a cryogenicist. Rather than the relative temperature scales of Celsius and Fahrenheit,...
: is the branch of physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
and engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
that studies the production and use of very low temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
s. Cryogenics is not cryonics, although people often confuse them.
Cryonics
Cryonics
Cryonics is the low-temperature preservation of humans and animals who can no longer be sustained by contemporary medicine, with the hope that healing and resuscitation may be possible in the future. Cryopreservation of people or large animals is not reversible with current technology...
: is the low temperature preservation of humans and mammals with the intention of future revival. Cryonics is not part of mainstream cryobiology. Cryonics still depends heavily on speculative future technology which may or may not be invented.
Cryopreservation
Cryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
: is a technology whereby cells, whole tissues, or embryos are preserved by cooling to temperatures below the freezing point of water.
Major areas of study in cryobiology
6 major areas of study in cryobiology can be identified:- Study of cold-adaptation of microorganismMicroorganismA microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
s, plantPlantPlants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s (= cold hardiness)Hardening (botany)Hardening in botany is the process by which an individual plant becomes tolerant to the effects of freezing during a period of weeks to months. It is a three stage process. During the first stage, carbohydrates are translocated to the roots of the plant and cell membrane permeability increases...
, and animalAnimalAnimals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s, both invertebrates and vertebrates (= hibernationHibernationHibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...
). - CryopreservationCryopreservationCryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
of cells, tissues, gameteGameteA gamete is a cell that fuses with another cell during fertilization in organisms that reproduce sexually...
s, and embryoEmbryoAn embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s of animal and human origin for (medical) purposes of long-term storage. This usually requires the addition of substances which protect the cells during freezingFreezingFreezing or solidification is a phase change in which a liquid turns into a solid when its temperature is lowered below its freezing point. The reverse process is melting....
and thawing (cryoprotectantCryoprotectantA cryoprotectant is a substance that is used to protect biological tissue from freezing damage . Arctic and Antarctic insects, fish, amphibians and reptiles create cryoprotectants in their bodies to minimize freezing damage during cold winter periods. Insects most often use sugars or polyols as...
s). - Preservation of organs under hypothermic conditions for transplantation.
- Lyophilization (freeze-dryingFreeze dryingFreeze-drying is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport...
) of pharmaceuticals. - CryosurgeryCryosurgeryCryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....
, a (minimally) invasive approach for the destruction of unhealthy tissue using cryogenic gases/fluids. - Physics of supercoolingSupercoolingSupercooling, also known as undercooling, is the process of lowering the temperature of a liquid or a gas below its freezing point without it becoming a solid....
, iceIceIce is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
nucleationNucleationNucleation is the extremely localized budding of a distinct thermodynamic phase. Some examples of phases that may form by way of nucleation in liquids are gaseous bubbles, crystals or glassy regions. Creation of liquid droplets in saturated vapor is also characterized by nucleation...
/growth and mechanical engineering aspects of heat transferHeat transferHeat transfer is a discipline of thermal engineering that concerns the exchange of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase-change transfer...
during cooling and warming.
Cryopreservation in nature
Many living organisms are able to tolerate prolonged periods of time at temperatures below the freezing point of water. Most living organisms accumulate cryoprotectantCryoprotectant
A cryoprotectant is a substance that is used to protect biological tissue from freezing damage . Arctic and Antarctic insects, fish, amphibians and reptiles create cryoprotectants in their bodies to minimize freezing damage during cold winter periods. Insects most often use sugars or polyols as...
s such as anti-nucleating proteins
Antifreeze protein
Antifreeze proteins or ice structuring proteins refer to a class of polypeptides produced by certain vertebrates, plants, fungi and bacteria that permit their survival in subzero environments. AFPs bind to small ice crystals to inhibit growth and recrystallization of ice that would otherwise be...
, polyols, and glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
to protect themselves against frost damage by sharp ice crystals. Most plants, in particular, can safely reach temperatures of −4 °C to −12 °C.
Bacteria
Three species of bacteria, Carnobacterium pleistoceniumCarnobacterium pleistocenium
Carnobacterium pleistocenium is a type of recently discovered bacterium from the arctic part of Alaska. It was found in permafrost, seemingly frozen there for 32,000 years. Melting the ice, however, brought these extremophiles back to life. This is the first case of an organism "coming back to...
, as well as Chryseobacterium greenlandensis
Chryseobacterium greenlandensis
Chryseobacterium greenlandensis is an Ultramicrobacteria species of bacteria that is able to live for long periods of time in habitats low-temperature, high-pressure, reduced-oxygen and nutrient-poor habitats. It is known to have survived for more than 120,000 years in an ice block in Greenland, at...
and Herminiimonas glaciei
Herminiimonas glaciei
Herminiimonas glaciei is a species of ultramicrobacterium in the family Oxalobacteraceae. These small gram-negative cells have a variable number of long flagella at the ends and sides of their rod-shaped bodies. With dimensions of 0.5–0.9 by 0.3–0.4 µm, H. glaciei is roughly 10 to 50 times...
, have reportedly been revived after surviving for thousands of years frozen in ice.
Certain bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, notably Pseudomonas syringae
Pseudomonas syringae
Pseudomonas syringae is a rod shaped, Gram-negative bacterium with polar flagella. It is a plant pathogen which can infect a wide range of plant species, and exists as over 50 different pathovars, all of which are available to legitimate researches via international culture collections such as the...
, produce specialized proteins that serve as potent ice nucleators, which they use to force ice formation on the surface of various fruits and plants at about −2 °C. The freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria.
Plants
Many plants undergo a process called hardeningHardening (botany)
Hardening in botany is the process by which an individual plant becomes tolerant to the effects of freezing during a period of weeks to months. It is a three stage process. During the first stage, carbohydrates are translocated to the roots of the plant and cell membrane permeability increases...
which allows them to survive temperatures below 0 degrees C for weeks to months.
Invertebrates
Nematodes that survive below 0 degrees C include Trichostrongylus colubriformis and Panagrolaimus davidi. CockroachCockroach
Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...
nymphs (Periplaneta japonica) survive short periods of freezing at -6 to -8 degrees C. The red flat bark beetle (Cucujus
Cucujus
Cucujus is a genus of beetle in family Cucujidae. It contains the following species:* Cucujus cinnaberinus...
clavipes) can survive after being frozen to -150 C. The fungus gnat
Fungus gnat
Fungus gnats are small, dark, short-lived flies, of the families Sciaridae, Diadocidiidae, Ditomyiidae, Keroplatidae, Bolitophilidae and Mycetophilidae , sometimes placed in the superfamily Mycetophiloidea, whose larvae feed on plant roots or fungi and aid in the decomposition of organic matter...
Exechia nugatoria can survive after being frozen to -50 C, by a unique mechanism whereby ice crystals form in the body but not the head. Another freeze-tolerant beetle is Upis ceramboides. See insect winter ecology
Insect winter ecology
Insect winter ecology entails the overwinter survival strategies of insects, which are in many respects more similar to those of plants than to many other animals, such as mammals and birds. This is because unlike those animals, which can generate their own heat internally , insects must rely on...
and antifreeze protein
Antifreeze protein
Antifreeze proteins or ice structuring proteins refer to a class of polypeptides produced by certain vertebrates, plants, fungi and bacteria that permit their survival in subzero environments. AFPs bind to small ice crystals to inhibit growth and recrystallization of ice that would otherwise be...
. Another invertebrate that is tolerant to temperatures down to -273 C is the water bear, an extremophile
Extremophile
An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles...
.
The larvae of Haemonchus contortus
Haemonchus contortus
Haemonchus contortus, also known as red stomach worm, wire worm or Barber's pole worm, is very common parasite and one the most pathogenic nematode of ruminants. Adult worms are attached to abomasal mucosa and feed on the blood...
, a nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
, can survive 44 weeks frozen at -196 C.
Vertebrates
For the wood frogWood Frog
The Wood Frog has a broad distribution over North America, extending from the southern Appalachians to the boreal forest with several notable disjunct populations including lowland eastern North Carolina...
(Rana sylvatica), in the winter, as much as 45% of its body may freeze and turn to ice. "Ice crystals form beneath the skin and become interspersed among the body's skeletal muscles. During the freeze the frog's breathing, blood flow, and heart beat cease. Freezing is made possible by specialized proteins and glucose, which prevent intracellular freezing and dehydration." The wood frog can survive up to 11 days frozen at -4 C.
Other vertebrates that survive at body temperatures below 0 C include painted turtles (Chrysemys picta), Gray tree frog (Hyla versicolor), Box turtles (Terrapene carolina)- 48 hours at -2 C, Spring peeper
Spring Peeper
The Spring Peeper is a small chorus frog widespread throughout the eastern USA and Canada.-Subspecies:There are two subspecies of the Spring Peeper, the Northern and the Southern Spring Peeper . The Northern is similar to the Southern except for a strong dark marking on the Southern frog's belly...
(Pseudacris crucifer), Garter snakes (Thamnophis sirtalis)- 24 hours at -1.5 C, the chorus frog
Chorus frog
Chorus frogs are a genus of frogs in the Hylidae family, and are found in North America on both sides of the Rocky Mountains from the San Francisco Bay Area to the Gulf of Mexico....
(Pseudacris triseriata), Siberian salamander
Siberian salamander
The Siberian salamander, Salamandrella keyserlingii, is a species of salamander found in Northeast Asia. It is found primarily in Siberia, in wet woods and riparian groves. There are also outlying populations in northern Kazakhstan and Mongolia, and also in northeastern China and on the Korean...
(Salamandrella keyserlingii), 24 hours at -15.3 C, Antarctic fish such as Pagothenia borchgrevinki and the European common lizard (Lacerta vivipara).
Professor Joshua Barr of the Staines Cyrobiology Laboratory in Middlesex (UK) has been carrying out experiments with British tree frogs to discover whether they also exhibit tolerance to very low temperatures in the same way as exhibited by American Tree Frogs. Thus far results have been inconclusive, however Professor Barr is optimistic about the future.
Hibernating Arctic ground squirrel
Arctic Ground Squirrel
The Arctic ground squirrel is a species of ground squirrel native to the Arctic.-Subspecies:Listed alphabetically.*S. p. ablusus Osgood, 1903...
s may have abdominal temperatures as low as -2.9 C, maintaining sub-zero abdominal temperatures for more than three weeks at a time, although the temperatures at the head and neck remain at 0 C or above.
Historical background
Hippocrates
Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...
to stop bleeding and swelling. With the emergence of modern science
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
, Robert Boyle
Robert Boyle
Robert Boyle FRS was a 17th century natural philosopher, chemist, physicist, and inventor, also noted for his writings in theology. He has been variously described as English, Irish, or Anglo-Irish, his father having come to Ireland from England during the time of the English plantations of...
studied the effects of low temperatures on animals.
In 1949 bull sperm
Spermatozoon
A spermatozoon is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote...
was cryopreserved
Cryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
for the first time by a team of scientists led by Christopher Polge
Christopher Polge
Ernest John Christopher Polge CBE, FRS was an English biologist, most noted for his work in cryopreservation....
(1926–2006). This led to a much wider use of cryopreservation
Cryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
today, with many organs
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
, tissues
Biological tissue
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
and cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
s routinely stored at low temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
s. Large organs such as heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
s are usually stored and transported, for short times only, at cool but not freezing temperatures for transplantation
Organ transplant
Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
. Cell suspensions (like blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
and semen
Semen
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
) and thin tissue sections can sometimes be stored almost indefinitely at liquid nitrogen
Liquid nitrogen
Liquid nitrogen is nitrogen in a liquid state at a very low temperature. It is produced industrially by fractional distillation of liquid air. Liquid nitrogen is a colourless clear liquid with density of 0.807 g/mL at its boiling point and a dielectric constant of 1.4...
temperature (cryopreservation
Cryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
). Human sperm, eggs and embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s are routinely stored in fertility
Fertility
Fertility is the natural capability of producing offsprings. As a measure, "fertility rate" is the number of children born per couple, person or population. Fertility differs from fecundity, which is defined as the potential for reproduction...
research and treatments. Controlled-rate and slow freezing are well established techniques pioneered in the early 1970s which enabled the first human embryo frozen birth (Zoe Leyland) in 1984. Since then machines that freeze biological samples using programmable steps, or controlled rates, have been used all over the world for human, animal and cell biology – 'freezing down' a sample to better preserve it for eventual thawing, before it is deep frozen, or cryopreserved, in liquid nitrogen. Such machines are used for freezing oocytes, skin, blood products, embryo, sperm, stem cells and general tissue preservation in hospitals, veterinary practices and research labs. The number of live births from 'slow frozen' frozen embryos is some 300,000 to 400,000 or 20% of the estimated 3 million IVF births. Dr Christopher Chen, Australia, reported the world’s first pregnancy using slow frozen oocytes from a British Controlled Rate freezer in 1986.
Cryosurgery
Cryosurgery
Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....
(intended and controlled tissue destruction by ice formation) was carried out by James Arnott in 1845 in an operation on a patient with cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
. Cryosurgery is not common.
Preservation techniques
Cryobiology as an applied scienceApplied science
Applied science is the application of scientific knowledge transferred into a physical environment. Examples include testing a theoretical model through the use of formal science or solving a practical problem through the use of natural science....
is primarily concerned with low temperature preservation. Hypothermic
Therapeutic hypothermia
Therapeutic hypothermia, also known as protective hypothermia, is a medical treatment that lowers a patient's body temperature in order to help reduce the risk of the ischemic injury to tissue following a period of insufficient blood flow. Periods of insufficient blood flow may be due to cardiac...
storage is typically above 0°C but below normothermic (32°C to 37°C) mammalian temperatures. Storage by cryopreservation
Cryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
, on the other hand, will be in the −80°C to −196°C temperature range. Organ
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
s, and tissue
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
s are more frequently the objects of hypothermic storage, whereas single cells have been the most common objects cryopreserved.
A rule of thumb in hypothermic storage is that every 10°C reduction in temperature is accompanied by a 50% decrease in oxygen consumption
Aerobic exercise
Aerobic exercise is physical exercise of relatively low intensity that depends primarily on the aerobic energy-generating process. Aerobic literally means "living in air", and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism...
. Although hibernating animals have adapted mechanisms to avoid metabolic imbalance
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
s associated with hypothermia, hypothermic organs and tissues being maintained for transplantation
Organ transplant
Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
require special preservation solutions to counter acidosis
Acidosis
Acidosis is an increased acidity in the blood and other body tissue . If not further qualified, it usually refers to acidity of the blood plasma....
, depressed sodium pump
Na+/K+-ATPase
Na+/K+-ATPase is an enzyme located in the plasma membrane in all animals.- Sodium-potassium pumps :Active transport is responsible for cells containing relatively high...
activity and increased intracellular calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
. Special organ preservation solutions such as Viaspan
Viaspan
Viaspan, also known as University of Wisconsin solution , was the first solution thoughtfully designed for use in organ transplantation, and became the first intracellular-like preservation medium...
(University of Wisconsin solution), HTK
Histidine-tryptophan-ketoglutarate
Histidine-tryptophan-ketoglutarate, or Custodiol HTK solution is a high-flow, low-potassium preservation solution used for organ transplantation....
, and Celsior have
been designed for this purpose. These solutions also contain ingredients to minimize damage by free radicals
Radical (chemistry)
Radicals are atoms, molecules, or ions with unpaired electrons on an open shell configuration. Free radicals may have positive, negative, or zero charge...
, prevent edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
, compensate for ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
loss, etc.
Cryopreservation of cells is guided by the "Two-Factor Hypothesis" of American cryobiologist Peter Mazur, which states that excessively rapid cooling kills cells by intracellular ice formation and excessively slow cooling kills cells by either electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....
toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
or mechanical crushing. During slow cooling ice forms extracellularly, causing water to osmotically
Osmosis
Osmosis is the movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, aiming to equalize the solute concentrations on the two sides...
leave cells, thereby dehydrating
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
them. Intracellular ice can be much more damaging than extracellular ice.
For red blood cell
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...
s the optimum cooling rate is very rapid (nearly 100°C per second), whereas for stem cell
Stem cell
This article is about the cell type. For the medical therapy, see Stem Cell TreatmentsStem cells are biological cells found in all multicellular organisms, that can divide and differentiate into diverse specialized cell types and can self-renew to produce more stem cells...
s the optimum cooling rate is very slow (1°C per minute). Cryoprotectant
Cryoprotectant
A cryoprotectant is a substance that is used to protect biological tissue from freezing damage . Arctic and Antarctic insects, fish, amphibians and reptiles create cryoprotectants in their bodies to minimize freezing damage during cold winter periods. Insects most often use sugars or polyols as...
s, such as DMSO (dimethyl sulfoxide
Dimethyl sulfoxide
Dimethyl sulfoxide is an organosulfur compound with the formula 2SO. This colorless liquid is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water...
) and glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
, are used to protect cells from freezing
Freezing
Freezing or solidification is a phase change in which a liquid turns into a solid when its temperature is lowered below its freezing point. The reverse process is melting....
. A variety of cell types are protected by 10% DMSO. Cryobiologists attempt to optimize cryoprotectant concentration (minimizing both ice formation and toxicity) as well as cooling rate. Cells may be cooled at an optimum cooling rate to a temperature between −30°C and −40°C before being plunged into liquid nitrogen
Liquid nitrogen
Liquid nitrogen is nitrogen in a liquid state at a very low temperature. It is produced industrially by fractional distillation of liquid air. Liquid nitrogen is a colourless clear liquid with density of 0.807 g/mL at its boiling point and a dielectric constant of 1.4...
.
Slow cooling methods rely on the fact that cells contain few nucleating
Nucleation
Nucleation is the extremely localized budding of a distinct thermodynamic phase. Some examples of phases that may form by way of nucleation in liquids are gaseous bubbles, crystals or glassy regions. Creation of liquid droplets in saturated vapor is also characterized by nucleation...
agents, but contain naturally-occurring vitrifying substances that can prevent ice formation in cells that have been moderately dehydrated. Some cryobiologists are seeking mixtures of cryoprotectants for full vitrification (zero ice formation) in preservation of cells, tissues and organs. Vitrification methods pose a challenge in the requirement to search for cryoprotectant mixtures that can minimize toxicity.
Cryobiology in humans
Human gametes and 2, 4 and 8-cell embryos can survive cryopreservationCryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
at -196°C for 10 years under well-controlled laboratory conditions.
Cryopreservation
Cryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
in humans with regards to infertility involves preservation of embryos, sperm or oocytes via freezing. Conception, in vitro, is attempted when the sperm is thawed and introduced to the 'fresh' eggs, the frozen eggs are thawed and sperm is placed with the eggs and together they are placed back into the uterus or a frozen embryo is introduced to the uterus. Vitrification has its glitches and is not as reliable or proven as freezing fertilized sperm, eggs or embryos as traditional slow freezing methods because eggs alone are extremely sensitive to temperature. Many researchers are also freezing ovarian tissue in conjunction with the eggs in hopes that the ovarian tissue can be transplanted back into the uterus, stimulating normal ovulation cycles. In Sep 2004 Prof Donnez of Louvain in Belgium reported the first successful ovarian birth from frozen ovarian tissue. In 1997 samples of ovarian cortex were taken from a woman with Hodgkin’s lymphoma and cryo-preserved in a (Planer, UK) controlled rate freezer and then stored in liquid Nitrogen. Chemotherapy was initiated and after the patient had premature ovarian failure. In 2003, after freeze-thawing, orthotopic autotransplantation of ovarian cortical tissue was done by laparoscopy and five months after reimplantation signs indicated recovery of regular ovulatory cycles. Eleven months after re-implantation a viable intrauterine pregnancy was confirmed, which resulted in the first such live birth – a girl called Tamara.
Therapeutic hypothermia
Therapeutic hypothermia
Therapeutic hypothermia, also known as protective hypothermia, is a medical treatment that lowers a patient's body temperature in order to help reduce the risk of the ischemic injury to tissue following a period of insufficient blood flow. Periods of insufficient blood flow may be due to cardiac...
, e.g. during heart surgery on a "cold" heart (generated by cold perfusion without any ice formation) allows for much longer operations and improves recovery rates for patients.
Scientific societies
The Society for Cryobiology was founded in 1964 to bring together those from the biological, medical and physical sciences who have a common interest in the effect of low temperatures on biological systems. As of 2007, the Society for Cryobiology had approximately 280 members from around the world, and one half of them are USUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
based. The purpose of the Society is to promote scientific research in low temperature biology, to improve scientific understanding in this field, and to disseminate and apply this knowledge to the benefit of mankind. The Society requires of all its members the highest ethical and scientific standards in the performance of their professional activities. According to the Society's bylaw
Bylaw
By-law can refer to a law of local or limited application passed under the authority of a higher law specifying what things may be regulated by the by-law...
s, membership may be refused to applicants whose conduct is deemed detrimental to the Society; in 1982, the bylaws were amended explicitly to exclude "any practice or application of freezing deceased persons in the anticipation of their reanimation," over the objections of some members who were cryonicists such as Jerry Leaf
Jerry Leaf
Jerry Donnell Leaf was Vice President and Director of the cryonics organization Alcor Life Extension Foundation, and President of the cryonics service firm Cryovita, Inc., until his cryopreservation by Alcor following a fatal heart attack in 1991.Leaf fought in special operations during the...
. The Society organizes an annual scientific meeting
Academic conference
An academic conference or symposium is a conference for researchers to present and discuss their work. Together with academic or scientific journals, conferences provide an important channel for exchange of information between researchers.-Overview:Conferences are usually composed of various...
dedicated to all aspects of low-temperature biology. This international meeting offers opportunities for presentation and discussion of the most up-to-date research in cryobiology as well as reviewing specific aspects through symposia and workshops. Members are also kept informed of news and forthcoming meetings through the Society newsletter, News Notes. The 2009-2010 President of the Society for Cryobiology is Barry J. Fuller.
The Society for Low Temperature Biology was founded in 1964 and became a Registered Charity
Charitable organization
A charitable organization is a type of non-profit organization . It differs from other types of NPOs in that it centers on philanthropic goals A charitable organization is a type of non-profit organization (NPO). It differs from other types of NPOs in that it centers on philanthropic goals A...
in 2003 with the purpose of promoting research into the effects of low temperatures on all types of organisms and their constituent cells, tissues and organs. As of 2006, the Society for Low Temperature Biology had approximately 130 (mostly British and European) members and holds at least one Annual General Meeting. The program usually includes both a symposium
Symposium
In ancient Greece, the symposium was a drinking party. Literary works that describe or take place at a symposium include two Socratic dialogues, Plato's Symposium and Xenophon's Symposium, as well as a number of Greek poems such as the elegies of Theognis of Megara...
on a topical subject and a session of free communications on any aspect of low temperature biology. Recent symposia have included long-term stability, preservation of aquatic organisms, cryopreservation of embryos and gamete
Gamete
A gamete is a cell that fuses with another cell during fertilization in organisms that reproduce sexually...
s, preservation of plants, low temperature microscopy
Microscopy
Microscopy is the technical field of using microscopes to view samples and objects that cannot be seen with the unaided eye...
, vitrification (glass formation of aqueous systems during cooling), freeze drying
Freeze drying
Freeze-drying is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport...
and tissue banking
Biomedical tissue
Biomedical tissue is biological tissue used for organ transplantation and medical research, particularly cancer research.Such tissues and organs may be referred to as: implant tissue, allograft, xenograft, skin graft tissue, human transplant tissue, implant bone. Tissue is stored in tissue...
. Members are informed through the Society Newsletter, which is presently published 3 times a year. The present chair (2010-2011) of the Society for Low Temperature Biology is Hugh Pritchard. A list of additional scientific societies (mostly using "applied" cryobiology) can be found here.
Journals
CRYOBIOLOGY, (publisher: ElsevierElsevier
Elsevier is a publishing company which publishes medical and scientific literature. It is a part of the Reed Elsevier group. Based in Amsterdam, the company has operations in the United Kingdom, USA and elsewhere....
) is the foremost scientific publication in this area, with approximately 60 refereed contributions published each year. Articles concern any aspect of low temperature biology and medicine (e.g. freezing, freeze-drying
Freeze drying
Freeze-drying is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport...
, hibernation, cold tolerance and adaptation, cryoprotective compounds
Cryoprotectant
A cryoprotectant is a substance that is used to protect biological tissue from freezing damage . Arctic and Antarctic insects, fish, amphibians and reptiles create cryoprotectants in their bodies to minimize freezing damage during cold winter periods. Insects most often use sugars or polyols as...
, medical applications of reduced temperature, cryosurgery
Cryosurgery
Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....
, hypothermia
Hypothermia
Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...
, and perfusion of organs).
CRYO LETTERS is an independent UK based rapid communication journal which publishes papers on the effects produced by low temperatures on a wide variety of biophysical and biological processes, or studies involving low temperature techniques in the investigation of biological and ecological
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
topics.
CELL PRESERVATION TECHNOLOGY is a peer-reviewed quarterly scientific journal
Scientific journal
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. There are thousands of scientific journals in publication, and many more have been published at various points in the past...
published by Mary Ann Liebert, Inc.
Mary Ann Liebert, Inc.
Mary Ann Liebert, Inc. is a publishing company founded by its current president, Mary Ann Liebert, in 1980. The company publishes peer-reviewed academic journals, books, and trade magazines in the areas of biotechnology, biomedical research/life sciences, clinical medicine, alternative/integrative...
dedicated to the diverse spectrum of preservation technologies including cryopreservation
Cryopreservation
Cryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
, dry-state (anhydrobiosis), glassy-state and hypothermic maintenance. Cell Preservation Technology has been renamed Biopreservation and Biobanking and is the official journal of International Society for Biological and Environmental Repositories (ISBER).
See also
- Antifreeze proteinAntifreeze proteinAntifreeze proteins or ice structuring proteins refer to a class of polypeptides produced by certain vertebrates, plants, fungi and bacteria that permit their survival in subzero environments. AFPs bind to small ice crystals to inhibit growth and recrystallization of ice that would otherwise be...
- CryogenicsCryogenicsIn physics, cryogenics is the study of the production of very low temperature and the behavior of materials at those temperatures. A person who studies elements under extremely cold temperature is called a cryogenicist. Rather than the relative temperature scales of Celsius and Fahrenheit,...
- CryonicsCryonicsCryonics is the low-temperature preservation of humans and animals who can no longer be sustained by contemporary medicine, with the hope that healing and resuscitation may be possible in the future. Cryopreservation of people or large animals is not reversible with current technology...
- CryopreservationCryopreservationCryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
- CryoprotectantCryoprotectantA cryoprotectant is a substance that is used to protect biological tissue from freezing damage . Arctic and Antarctic insects, fish, amphibians and reptiles create cryoprotectants in their bodies to minimize freezing damage during cold winter periods. Insects most often use sugars or polyols as...
- CryosurgeryCryosurgeryCryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....
- CryptobiosisCryptobiosisCryptobiosis is an ametabolic state of life entered by an organism in response to adverse environmental conditions such as desiccation, freezing, and oxygen deficiency. In the cryptobiotic state, all metabolic procedures stop, preventing reproduction, development, and repair...
- FreezingFreezingFreezing or solidification is a phase change in which a liquid turns into a solid when its temperature is lowered below its freezing point. The reverse process is melting....
- Freeze dryingFreeze dryingFreeze-drying is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport...
- HibernationHibernationHibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...
- HypothermiaHypothermiaHypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...
- IceIceIce is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
- Insect winter ecologyInsect winter ecologyInsect winter ecology entails the overwinter survival strategies of insects, which are in many respects more similar to those of plants than to many other animals, such as mammals and birds. This is because unlike those animals, which can generate their own heat internally , insects must rely on...
- Institute for Problems of Cryobiology and CryomedicineInstitute for Problems of Cryobiology and CryomedicineThe Institute for Problems of Cryobiology and Cryomedicine in Kharkiv is one of the institutes of the National Academy of Science of Ukraine, and is the largest institute devoted to cryobiology research in the world. Established in 1972, the focus of the research is on cryoinjury, cryosurgery,...
- Organ transplantOrgan transplantOrgan transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
- PerfusionPerfusionIn physiology, perfusion is the process of nutritive delivery of arterial blood to a capillary bed in the biological tissue. The word is derived from the French verb "perfuser" meaning to "pour over or through."...
- Tissue EngineeringTissue engineeringTissue engineering is the use of a combination of cells, engineering and materials methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions...
External links
- Society for Cryobiology
- Society for Low Temperature Biology
- CRYOBIOLOGY
- CryoLetters
- Cell Preservation Technology
- 43rd Annual Meeting of the Society for Cryobiology in association with the Society for Low Temperature Biology, July 23 - 27, 2006, Hamburg, Germany
- 44th Annual Meeting of the Society for Cryobiology, July 28 - August 1, 2007, Lake Louise, Canada
- 45th Annual Meeting of the Society for Cryobiology, July 20 - 23, 2008, Charlotte, NC, USA
- 46th Annual Meeting of the Society for Cryobiology, July 19 - 23, 2009, Sapporo, Japan
- 47th Annual Meeting of the Society for Cryobiology, July 17 - 20, 2010, Bristol, UK
- 48th Annual Meeting of the Society for Cryobiology, July 24 - 27, 2011, Corvallis, OR, USA
- 49th Annual Meeting of the Society for Cryobiology, June 3 - 6, 2012, Rosario, Argentina
- Cellular cryobiology and anhydrobiology
- An overview of the science behind cryobiology at the Science Creative Quarterly