Re: Cryoprotectants anyone?

Eugene Leitl (
Tue, 16 Dec 1997 16:42:16 +0300 (MSK)

On Sat, 13 Dec 1997, Twink wrote:

> Here is the schema:
> Engineering cryoprotectants:
> [...]

Structural conservation would be just fine (functional proof is too
restrictive, imo). However, it is technically most difficult to test.
Maybe, with the advent of xray microscopy... It would help a lot if there
was an encompassing theory of cryodamage. The exciting field of
cryobiology does not seem to draw too many followers/funds, however.
No-one hinders you from going out, and becoming a cryobiologist. Just
never, ever say 'cryonics' in public.

> Next, find existing chemicals that meet one or more of the specs. There are

It is that 'testing for specs' that is expensive. There is simply no
certified easy/cheap/fast in-vitry model in existance, besides of the
animal model (dogs/sheep), which is neither.

> already a few good cryoprotectants in use, but I mean any chemical
> whatsoever. This is almost a form of brainstorming. The idea is to widen
> the scope of the search in hopes of a serendipitous solution.

When it comes to choosing nomes de plume I'd avoid any combinations of
'Visser' if I were you...

> We can also use genetic algorithmns and the like to come up with a
> molecular design and try to create a compound or set of compounds

Once again, you wouldn't be able to check much with your computer model.
Personally, I think it to be the most promising approach on the long run
(when we will have progressed to understanding the cell in terms of its
molecular processes). This is strictly for the future, however.

> from the results. This is sort of like crossing a butterfly with a bee to
> come up with a graceful stinging bug. Many of the crossbreeds will
> be unviable monsters, but one might work.
> After this, the cryoprotectant can be tested on nerve cells and perhaps
> networks of nerves. (Has such already been done? I am talking about

I once suggested using neural cultures on multi-electrode arrays for such
a model on murg (functional check). I don't know whether anything ever
came out if it.

> examining the connections between cells -- which most assume are
> responsible for how the brain behaves, including the mind -- for
> damage.) Finally, the cryoprotectant will be tested on whole systems,
> such as a whole mouse that is alive.

I don't think fully reversible cryosuspension is physically possible, even
on systems as small as the mouse. Mouse embryos, yes. Adult mice, no.