title: Cryopreserved agarose-encapsulated islets as bioartificial pancreas: a feasibility study.
abstract: BACKGROUND
  A bioartificial pancreas in which islets of Langerhans (islets) are encapsulated within a semipermeable membrane, such as agarose, has been proposed for treating type I diabetic mellitus. However, the long-term storage for providing a convenient and easily accessible supply still remains an issue. We investigated cryopreservation as a potential method of long-term storage for agarose-encapsulated islets (Mic-islets).
  
  
  METHODS
  The morphology, insulin secretion, and histochemical staining of cryopreserved Mic-islets were analyzed. Streptozotocin-induced diabetic mice were transplanted intraperitoneally with 1000, 2000, and 3000 Mic-islets after cryopreservation in KYO-1 vitrification solution. Blood glucose levels were measured and immunohistochemical analyses were performed at 41 days posttransplantation.
  
  
  RESULTS
  Transplanted cryopreserved Mic-islets restored normoglycemia in diabetic mice. The mean (+/-SD) normoglycemic periods were 32.0+/-13.2 days and 46.3+/-13.3 days for recipients of 1000 (n=5) and 2000 (n=4) cryopreserved Mic-islets, respectively, whereas the mean normoglycemic period was 53.2+/-16.7 days for recipients of 1000 noncryopreserved Mic-islets (n=7). These data indicate that cryopreserved Mic-islets transplanted as a bioartificial pancreas successfully controlled blood glucose levels for extended periods.
  
  
  CONCLUSIONS
  Cryopreserved agarose-encapsulated islets could successfully control the blood glucose level for a long period as a bioartificial pancreas.
authors.affiliation: Department of Reparative Materials, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Agudelo
authors.forename: Yuji
authors.initials: Y
authors.lastname: Teramura
authors.forename: Hiroo
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D006224:Cricetinae; D015925:Cryopreservation; D003451:Cryoprotective Agents; D005240:Feasibility Studies; D005260:Female; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism; D016381:Islets of Langerhans Transplantation; D008647:Mesocricetus; D051379:Mice; D019397:Pancreas, Artificial; D012685:Sepharose
chemical_list: D001786:Blood Glucose; D003451:Cryoprotective Agents; D007328:Insulin; D012685:Sepharose