X-Message-Number: 12372
Date: Mon, 6 Sep 1999 01:13:17 -0700 (PDT)
From: Doug Skrecky <>
Subject: intracellular trehalose(or sucrose) may be the key

  Reduction of extracellular ice crystal induced cellular dehydration
and consequent membrane damage may be the secret here. It is possible
similar results might be obtained with many slowly permeating
cryoprotectants. Once inside cells these will help fight any dehydration

---------- Forwarded message ----------
Date: Tue, 31 Aug 1999 06:32:44 -0700 (PDT)
From: Doug Skrecky <>
Subject: intracellular trehalose(or sucrose) may be the key

  Beattie GM.  Crowe JH.  Lopez AD.  Cirulli V.  Ricordi C.  Hayek A.
  Whittier Institute, Department of Pediatrics, University of California at San
  Diego School of Medicine, La Jolla 92037, USA.
  Trehalose: a cryoprotectant that enhances recovery and preserves function of
  human pancreatic islets after long-term
  Diabetes.  46(3):519-23, 1997 Mar.
  The scarcity of available tissue for transplantation in diabetes and the need
  for multiple donors make it mandatory to use an optimal cryopreservation
  method that allows maximal recovery and preservation of beta-cell function.
  We have developed a method to cryopreserve islets with excellent survival of
  endocrine cells. Current methods use DMSO as cryoprotectant. Our method
  involves introducing both DMSO and the disaccharide trehalose into the cells
  during cooling. Uptake and release of trehalose occurred during the
  thermotropic lipid-phase transition measured in pancreatic endocrine cells
  between 5 degrees and 9 degrees C, using [14C]trehalose. Recovery of adult
  islets after cryopreservation with 300 mmol/l trehalose was 92 vs. 58% using
  DMSO alone. In vitro function, in terms of insulin content and release in
  response to secretagogues, was indistinguishable from fresh islets. Grafts
  from islets cryopreserved with trehalose contained 14-fold more insulin than
  grafts from islets cryopreserved without trehalose. Results with human fetal
  islet-like cell clusters (ICCs) were more pronounced: recovery from
  cryopreservation was 94%, compared with 42% without trehalose. Complete
  functionality of fetal cells was also restored; tritiated thymidine
  incorporation and insulin content and release were similar to fresh tissue.
  After transplantation in nude mice, there was a 15-fold increase in insulin
  content of grafts from ICCs cryopreserved with trehalose compared with ICCs
  cryopreserved without trehalose. Thus, the addition of trehalose to
  cryopreservation protocols leads to previously unobtainable survival rates of
  human pancreatic endocrine tissue.

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