Freeze Recovery Drug - Step Toward Suspended Animation?

arete writes "Apparently a simple injection (in rats and mice so far) can revive body functions before warming. Since you're cold, your brain isn't using oxygen, and doesn't go into oxygen deprivation. But it lets breathing and autonomic functions (like shivering) restart even in the absence of a brain restart. Sounds to me like a big leap towards suspended animation. Of course, you can't be frozen below 0 C using this techique, because all your cells explode when the water freezes. Plausibly with some mild oxygen influx you wouldn't need to be below 0 C, though. " I think I'll wait a while before planning my interstellar trip, tho'.

Comments

Why would people from the future unfreeze you!?

[systemapex]

Let's see... In a thousand years when mankind is capable of unfreezing these carcasses and reviving them back into living people, what will honestly be their reason for doing so? They'll look back in their history "books" and see that our generation was characterized by people who over-consumed, over-polluted, intellectually under-performed (for the most part), and was also characterized by many people who become more excited by the entrance music of some WWF wrestler than by fantastic scientific discoveries that accomplish real work and have practical applications. Right...I'm sure they'll be quick to unfreeze the carcasses circa 20th century - early 21st century:)

And Walt Disney was never frozen either...

[crasch]

Just a note of clarification. Although it is true that ice crystallization causes extensive cellular damage, it does not do so by causing cells to explode as the ice expands. Rather, at freezing rates possible in tissues, ice tends to form in the extracellular space first. As ice crystals form in the extracellular space, the chemicals in the unfrozen extracellular fluid become increasingly concentrated (because ice freezes as pure water). Osmotic forces cause water inside the cell to cross the cell membrane. So the cell actually dehydrates and shrinks during freezing. If the cell dehydrates too much, the cell membrane irreversibly collapses into a gel state. (It is true however, that the expansion of ice causes damage to macroscopic structures, such as capillary beds.) Please see this excellent review article by Ken Storey, in which he reviews the mechanisms of freezing damage, and discusses naturally freeze tolerant organisms such as the wood frog, Rana sylvatica.

For a good review of the problems that need to be overcome to achieve suspended animation, see The Contributions of Low Temperature Science to Cryobanking and the Prospect of Suspended Animation for Manned Space Travel by Michael J. Taylor, Ph.D., Debra J. Battjes Siler, M.S., John R. Walsh, Ph.D., Kelvin G.M. Brockbank, Ph.D. in Graft, May 2050, volume 3, issue 3 (also known as Volume 3, Issue 3, May/June 2000).

In my opinion, the currently most likely near term pathway to suspended animation lies in the use of vitrification. Vitrification involves introducing a sufficiently high concentration of cryoprotectant into an organ such that upon cooling, the fluid within the organ forms a glass instead of a crystal, thereby avoiding the problem of ice crystallization altogether. Please see this review article Organ Cryopreservation by Greg Fahy, PhD. for a succinct review of the approach and numerous references to the available literature.

Finally, I would caution that the New Scientist is not a particularly discriminating science news source. For example, see the September 28, 1996 New Scientist article (p.22) regarding Olga Visser, a South African perfusionist at the University of Pretoria, who claimed that she had found a technique for successfully cryopreserving rat hearts at liquid nitrogen temperatures. In cryobiology circles, this is like someone claiming a cure for cancer. It is one of the "big problems" in cryobiology, that a number of scientists have spent decades trying to solve. Visser's claim could not be duplicated and were never published in a peer reviewed journal. Even worse, Visser later claimed that the same drug she used to achieve the holy grail of cryobiology, dimethylformamide, was also a cure for AIDS.

Freezing doesn't truly burst cells...

[AlephNot]

In Chapter 9 of Drexler's Engines of Creation, the author states, "It is a common myth that freezing bursts cells; in fact, freezing damage is more subtle than this - so subtle that it often does no lasting harm. Frozen sperm regularly produces healthy babies. Some human beings now alive have survived being frozen solid at liquid nitrogen temperatures - when they were early embryos."

I personally recommend a read of the entire book (it's all online), but this chapter seems to have the most to do with the discussion.