Cryonicists do not believe in the word death. These scientists prefer the word deanimation, a term that implies reanimation is possible.
Cryonicists believe cryonics, the preservation of humans and animals by freezing them, is the key to an extended life.
Human bodies do not decompose as long as they are frozen in liquid nitrogen. However, freezing wreaks havoc on the body. If the cell cools down too quickly, and the freezing rate is faster than the rate of water loss through the cell membrane, ice crystals will form, and the cell might burst. Even if the cooling is appropriately gradual, ice could still form between cells.
To protect cells during the freezing process, scientists use cryoprotectants. Glycerol, the most common of these cryoprotectants, decreases ice formation and reduces tissue damage but not enough for the tissue revival.
To further fight injuries from ice formation, scientists also use a process called vitrification, or the process of turning a substance — in this case, humans — into glass. Vitrification prevents damage that freezing causes but, for reasons scientists don’t understand, it is toxic to the human body.
Biomedical engineering professor Kenneth Diller, president of the Society for Cryobiology from 1994–1995, said cryopreservation poses serious problems for scientists.
“There’s no problem with freezing somebody,” Diller said. “The real issue develops when you try to thaw them out.”
Cryonicists struggle with logistical issues involved with preservation. If the human body is deprived of oxygen and nutrients for more than 12 minutes, patients are considered to be irretrievable, according to the American Heart Association. Cold temperatures prevent this problem, but patients who are not frozen quickly suffer irreversible damage.
Despite these challenges, the Cryonics Institute believes advances in bioengineering and nanotechnology will make cryopreservation a viable option for the future.
Some organs can be cryopreserved and rewarmed to their original capacities. Researchers at UT work on the preservation of kidneys for transplants. Yuri Pichugin, director of research for the Cryonics Institute from 2001–2007, detected electrical activity in a previously frozen rabbit brain.
Many people don’t agree with the idea of cryonics for moral or religious reasons — and even plain skepticism. UT students had differing opinions as to whether they would volunteer as cryopreservation candidates.
“I’m open to the idea,” human biology senior Cristian Sandoval said. “Seeing the future would be very cool.”
Chemical engineering junior Luis Limon said he disagrees with cryonics for religious reasons.
“I believe when it’s our time to go, it’s the right time to go,” Limon said.
While individual cells and some tissues can be cryopreserved and revived, the complete freezing of every tissue in the human body causes irreversible damage with modern technology. Candidates for the freezing process can choose to preserve their entire bodies — from the head to just DNA. Diller said cryonics is still a distant goal in the field of temperature research.
“I wouldn’t hope for immortality in your lifetime unless something unforeseen develops,” Diller said. “We have no mechanistic understanding of how that could happen, but that doesn’t guarantee that something we don’t understand is going to come along.”