CRYOprotectants: Reply to Leitl

Twink (
Sun, 28 Dec 1997 23:49:31 -0500 (EST)

At 04:42 PM 12/16/97 +0300, Eugene Leitl <>
>> 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.

That would be very good indeed. See below.

>The exciting field of
>cryobiology does not seem to draw too many followers/funds, however.

That could change.

>No-one hinders you from going out, and becoming a cryobiologist. Just
>never, ever say 'cryonics' in public.

I don't know if I can. Maybe I shall, but it might preclude other options in my
life. Can anyone give an estimate on how many person-hours it would take
to go from intelligent layperson to cryobiologist -- assuming I am the former?

>> 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.

Then, perhaps, it is time to develop -- even one that only works sometimes. A
bad model can be improved. No model is worse, don't you think? I think there
is enough information to build a rough model that can be improved.

>> 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.

"In fifteen minutes, we'll all be in the future." Someone once said. (Was it
Bob Black?:) Anyway, see above.

>> 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.

It's a good idea and I think the Prometheus project is actually doing some-
thing close enough, though we'll have to see.

>> 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.

Why not?

Daniel Ust