X-Message-Number: 30114
Date: Fri, 07 Dec 2007 23:19:08 -0500
Subject: Cryoprotectant toxicity

      I applaud Douglas Skrecky for his attention to the
problem of cryoprotectant toxicity, although his analysis
leaves much to be desired:


      Referring to osmotic damage as cryoprotectant toxicity
is a gross category error. His analysis of his other
two types of toxicity also misses the point in my opinion.
I doubt that metabolism of ethylene glycol to oxalic acid
("calcium oxalate") is relevant to the problems of  cryogenic
vitrification. Despite many other criticisms I could make,
some of the issues he raises are worthy of attention.

       Experimentation and speculation to date has not provided
a very clear idea of the mechanisms of cryoprotectant
toxicity and how to prevent it. If there should be a
Manhatten Project in cryonics it should be devoted to
the problem of cryoprotectant toxicity. Resources
allocated to nanotechnology, whole body vitrification,
intermediate temperature storage, etc. may be of some
value, but they can also be a distraction. I would
rather concentrate on the root problem. I would rather
see intellectual and financial resources devoted to
the central issue of cryopreservation by vitrification.

       Maximizing vitrification while minimizing toxicity
is the very best means of advancing cryonics and our
survival. Understanding cryoprotectant toxicity can
be the key to preserving brains and bodies. Vitrification
mixtures that are non-toxic enough to preserve human
organs at cryogenic temperatures without loss of
viability would attract vast amounts of research
investment which would further advance the science.
Non-toxic vitrification mixtures could make true
suspended animation (reversible whole body
vitrification)  possible. Conventional medicine in
  hospitals,  clinics and universities would understand
the lifesaving reality of our goals of reducing ischemic
damage by hypothemia, CPS and other means.

       Cryoprotectant toxicity is the key to it all.

        A couple of sections of pages on my website
are very focused on the question of cryoprotectant



        I have been updating these sections recently and
expect to be making more updates in the near future.
Watch these links if cryoprotectant toxicity is of
interest to you.

            -- Ben Best

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