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Thanks to hibernation, some animals can survive very low temperatures, and with the onset of heat, return to their usual way of life. Scientists believe that in the future a similar technology will appear for humans
What is suspended animation
Anabiosis (from the Greek Anabíōsis – “return to life”) is a state of the body in which vital processes (respiration, heartbeat) temporarily stop, but can resume to a normal level under favorable conditions. Some living beings can fall into hibernation to survive in case of a sharp deterioration in the external environment – changes in temperature, humidity, access to water, and so on.
Anabiosis is not the same as hibernation, which some animals fall into (in science – hibernation). As Igor Artyukhov, director of science at the cryonics company Kriorus, explains, during hibernation, life processes in the body slow down, but continue. Body temperature in this state does not drop much: in a bear, for example, only a few degrees; in other animals that hibernate – up to plus 4–6 ° С. With prolonged cold anabiosis, the body temperature drops significantly below zero and life processes in the body completely stop.
So far, the process of anabiosis occurs only in the natural environment – in small living organisms, to which it is characteristic. However, scientists over the past decades have been trying to create technologies with which it would be possible to keep the human body in a cold state in order to revive it later. If scientists manage to put a person into hibernation and bring him out of this state, this will open up new opportunities for medicine and space exploration. We understand how suspended animation works and where it can be applied in decades.
Anabiosis in animals
Anabiosis in animals was discovered by the Dutch naturalist Anthony van Leeuwenhoek in 1701. He put wet sand into a glass tube with water and under a microscope found living rotifers in it – this is the name of protostomes up to 2 mm in size. Later, by other naturalists, it was discovered in tardigrades, microscopic invertebrates. These are animals about half a millimeter in size that live in water bodies and in mosses near them. Falling into suspended animation, tardigrades can adapt to different conditions, for example, survive temperatures of minus 20 ° C for 30 years.
As Igor Artyukhov explains, organisms can fall into suspended animation under two conditions. The first is associated with dehydration – the body loses a large amount of fluid and the chemical processes in it stop. Tardigrade, for example, in suspended animation retains only up to 1% of the fluid, the limbs of its body fold, and the body decreases in volume. The second is associated with a significant cooling of body temperature.
Why does humanity need hibernation
There are several options where suspended animation can be used in the future for a person.
Explore outer space
“For the exploration of deep space, the key condition is the emergence of engines that are able to bring a spacecraft to the nearest star not in a billion years, as it is now, but at least in a hundred. When such a ship appears, the question will arise – how to save a person’s life during this flight? According to forecasts, cosmonauts can be put into a state of suspended animation on Earth, and in space, when approaching a star or another planet, “wake up” with the help of technologies that are not yet available,” says Evgeny Kuznetsov, a futurologist and founder of the Orbita Capital Partners venture fund. In his opinion, such ships will appear in 20-30 years – and then the technology of introducing a person into suspended animation will become in demand.
Save people with incurable diseases
It will be possible to put people with incurable or orphan (rare) diseases into a state of suspended animation in the hope that in the future there will be methods of their treatment or drugs will become more accessible. “Consider the scenario of a 5-year-old girl who is diagnosed with a progressive, incurable disease. Since the available treatments would only extend her predicted survival by 1 year, she is placed in suspended animation. She partially recovers every few years as new treatments emerge that can have a significant impact on her recovery. After 35 years in suspended animation, she makes a full recovery as a cure for her illness is finally found. But biologically, this girl only ages a few months,” writes astrobiologist David Warmflash. He notes that this is a hypothetical scenario that raises a number of questions: where will the resources come from to care for a patient in a state of suspended animation and how a person will adapt, once in a completely different world.
For organ transplant
In a state of suspended animation, it will be possible to save donor organs for subsequent transplantation, says Igor Artyukhov. “Now in transplantation there is a problem of compatibility. When an organ appears, doctors often need more time to check it for compatibility with the patient’s body and for infections. And the vitality of the organ is declining every hour. If it were possible to preserve these organs for a long time, it would radically change medicine, ”he says.
Is anabiosis possible in humans
What research is being done
According to experts interviewed by Trends, research on human suspended animation is still at an early stage. Scientists are studying the possibilities of hibernation more and conducting experiments on animals. At the same time, in the history of medicine there are examples when a person under natural conditions plunged into a state similar to suspended animation and came out of it. For example, in 1999, Swedish doctor Anna Bogenholm fell through the ice while skiing and spent 80 minutes in cold water. Her heart stopped and her body temperature dropped to 13,7°C. The doctors managed to resuscitate the girl and bring her back to life.
Also in medicine, scientists are exploring the possibility of using the hypothermic method in the treatment of patients – according to the principle of operation, this is similar to suspended animation. Hypothermia is an abnormally low body temperature that dramatically reduces the human body’s need for oxygen. Doctors are trying to induce hypothermia in patients by replacing their blood with very cold salt water to cool their whole body down to 10°C in 15 minutes. Normally, we cannot survive without blood – it carries the oxygen that cells need to generate energy. However, when body temperature is very low, cellular activity ceases and cells survive without oxygen, thus preventing further tissue and organ damage.
The US government authorized such research in 2014 by a medical team at the University of Pittsburgh led by physician Samuel Tisherman. The study was conducted in one of the American hospitals. The plan was for physicians to compare the survival of patients resuscitated with hypothermia with the survival of patients resuscitated with conventional methods. It was attended by people with gunshot or stab wounds and great blood loss; hypothermia was allowed if the heart stopped no later than 5 minutes before the start of the procedure.
Tischerman’s team was the first in the world to put a person into suspended animation in 2019. The doctor, speaking about the experiment, did not say whether the patient survived and added that research into hypothermia would continue.
Where is it used now
Now methods similar to the introduction of a person into suspended animation are used in cryonics. “This can be considered anabiosis of cells. Because if a person died, his heart stopped, 99% of the cells are still alive and most of them are alive for several hours or days. Unfortunately, brain cells begin to die within a few hours, but if the head is cooled to a temperature close to zero, as in hypothermia, then they can already last up to several days in this state. Next, a person is immersed in a state of deep cooling for preservation, ”he explains.
For cryopreservation, a person replaces the blood in the body with a non-freezing composition – a cryoprotectant, which prevents cell damage during freezing. After that, the body is frozen to the temperature of liquid nitrogen – minus 196 ° C – and placed in storage in special vessels.
Now there are 84 people and 47 animals in cryostorage “Kriorus”. People during their lifetime decided to take this step in the hope that in the future they will be able to revive, cure and rejuvenate. Under Russian law, a person can be cryopreserved only after a legal death.
Why research is slow
According to experts, the advancement of science in matters of immersing a person in suspended animation is slow. According to Trends’ interlocutors, this is due to the lack of interested people in research and, as a result, sufficient funding. “This problem is similar to the problem of treating orphan diseases. When a disease is rare, neither the state nor insurance companies have enough money to develop medicines for it,” says Evgeny Kuznetsov. According to him, the use of suspended animation for humans is a solution to a fundamental issue in biology, which will require tens of billions of dollars. He notes that with the necessary funding, scientists, in an optimistic scenario, would be able to develop a technology for immersing a person in and out of suspended animation in 3-5 years, and they would need the same amount to certify the technology. “But whether it will be possible to develop it is a question. When the result is written with a pitchfork in the water, not a single investor will invest such an amount in development. This is a characteristic dead end of any new technology, when there is no proven demand for it yet,” says Kuznetsov.
However, experts give different estimates on the timing of the emergence of technology to restore a person after a state of suspended animation. According to Igor Artyukhov, scientists will need more time to create it – 20-30 years. “Given how technology is developing in medicine, such a period is quite possible. The main thing is to do it for the first time and prove to the entire scientific community that this is possible,” he says. As Artyukhov notes, now human suspended animation remains a gray area: theoretically, this technology is possible, but has not yet been implemented in practice.