: how is cryopreservation able to somewhat preserve and sustain a person without them slowly dying due to a lack of basic necessities like oxygen and water?


: how is cryopreservation able to somewhat preserve and sustain a person without them slowly dying due to a lack of basic necessities like oxygen and water?

In: Other

You need water and oxygen (and other things) to fuel the whole cell respiration process. The idea behind cryopreservation is to slow down those same cellular processes. So since they’re respiring slower, they require less oxygen, water, etc.

Basically, it doesnt. As of 2021, the humanity does not have the knowledge to bring back a whole body to life after it is completely frozen. That is, the current cryopreservation methods are not applicable to a human body.

However, individual cells, and sometimes tissues can be preserved that way. It is quite common to freeze and thaw cell lines while keeping them alive in the process. Lately, I thawed a vial of cells frozen in 2012, and a small percentage of them managed to recover from the process and live normally. But, they are just individual cells, not a whole body.

As the cells freeze, the water in them crystallizes. And that can be a problem, as it shreds the cells and compromise their integrity. Therefore, the water in the cells should be replaced with something else that does not form such disruptive crystals while freezing. A chemical called DMSO is used for such purpose. Also, the temperature should be gradually decreased to prevent the shredding. So when we freeze the cells, they go into a freezer at 4 degree Celcius first. Then -20, -80, and finally into liquid nitrogen vapor, that is around -190 degree Celcius. This is where they are kept for long term.

In theory cryopreservation works by putting your cells in a kind of stasis. Your body’s chemical functions need energy in the form of heat to work so that the different molecules and enzymes can move around and interact with each other. If you lower the temperature enough then those molecules can’t move around any more, so all of the chemical reactions in your body stop. If you can do that in a way that keeps the cells intact, then you can perfectly preserve the cells in a state of suspended animation, ready to resume when thawed.

Now I say “in theory” because there’s no actual evidence that doing this to a human actually preserves them to a degree where you’d be able to revive them again later. It works for cultured cells grown in a lab, but you have to freeze a lot of cells at a time because ~50% of them will die as soon as you thaw them out – if that happened to a human that would be very bad indeed. But it can certainly be used to prevent the body from decaying if someone is already dead.

you do die, you brain and heart stop, your metabolism stops so there is no need to consume any oxygen. You are dead with the caveat that you don’t decay and can be “revived” because all your tissues are still mostly intact.

You need oxygen and water and nutrients because those are fuel that sustains the constant chemical reaction that is your existence.

Freezing stops that chemical reaction. The human body becomes similar to a parked car. All the machinery and fuel is ready to move when you introduce the spark to start the reaction again. Heat instead of a literal spark for a frozen human.

It should work fine as soon as we find a way to freeze people without ice crystals shredding our cells apart on a massive and lethal scale.