X-Message-Number: 18392
From: "Igor Artyuhov" <>
Subject: Pressure Assisted Freezing and Thawing
Date: Tue, 22 Jan 2002 16:19:55 +0300

This is a multi-part message in MIME format.

------=_NextPart_000_0AE2_01C1A360.A0F0AD40
Content-Type: text/plain;
	charset="koi8-r"

Source: "High-pressure biotechnology in medicine and pharmaceutical 
science" by Patrick Masson, Carole Tonello and Claude Balny; 
Journal of Biomedicine and Biotechnology 1:2 (2001) pp. 85-88 
(http://www.hindawi.dk/journals/jbb/volume-1/S1110724301000158.pdf)

>>>

< Skipped >

PRESSURE-ASSISTED FREEZING ANDTHAWING
AND STORAGE AT SUBZERO TEMPERATURE
WITHOUT FREEZING

The solid-liquid phase diagramof water shown that water
remains liquid down to ?20C under a pressure of 2 kbar [4].
Several applications of the effect of high pressure on the phase
transitions of water are currently under development in food
technology and more recently for possible applications for the
preservation of biopharmaceuticals, blood derivatives, cells,
and organs for transplant.A1960 study showed that pressureassisted
thawing could improve the survival rate of slowly
frozen human conjunctiva and chick skin cells [14].
The freezing induction of a product cooled at temperature
from ?10C to ?20C under a pressure of 1 kbar to 4 kbar
is quite instantaneous when pressure is release. Less structural
damages are noticed for products frozen with the help
of pressure than with ?30C air or with liquid nitrogen at
atmospheric pressure. This technique has been used for cryo-
?xation of samples for electron microscopy. It could probably
allow fragile biopharmaceutical products to be frozen without
damage.
The properties of water under pressure allow also bioproducts
to be stored at subzero temperature without freezing.
The process (an increase of pressure up to 1-2 kbar, followed
by a cooling and a reheating before depressurization)
has less dramatic effects than freezing and thawing processes.
The contaminating microorganisms and spoiling enzymes
are reduced during this subzero temperature nonfrozen
storage.


< Skipped >

[14] Taylor AC. The physical state transition in the freezing
of living cells. Ann NY Acad Sci. 1960; 85:595-609.

< Skipped >

<<<

IMHO this approach is similar to Mr. Best's ideas on "High 
pressure cryonics" - I. A.

------=_NextPart_000_0AE2_01C1A360.A0F0AD40

 Content-Type: text/html;

[ AUTOMATICALLY SKIPPING HTML ENCODING! ] 

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=18392