title: The development of alternative vitrification solutions for microencapsulated islets.
abstract: Bioartificial pancreas in which islets of Langerhans (islets) are enclosed in a semipermeable membrane is one of the approaches to treat insulin-dependent diabetic patients. Although there are advantages in this method, one of the issues that still remains is the long-term storage of tissue engineering devices before transplantation. One of the possible routes to address this is through cryopreservation. In this study, a freezing solution, 2 m DMSO in RPMI-1640, a conventional vitrification solution, VS55, and the newly developed vitrification solution KYO-1 were examined to cryopreserve microencapsulated islets in agarose hydrogel. The insulin release ability, morphology of islets, and physico-chemical properties of the agarose gel membrane were examined after a cryopreservation and thawing process. Frozen and vitrified (by KYO-1) groups showed a similar insulin secretion. Frozen groups by 2 m DMSO, however, showed destruction of agarose capsules and some islets were out of the capsule. When KYO-1 was used, islets still maintained the ability to release insulin in response to glucose stimulation, and agarose capsule showed morphological integrity, and mechanical properties. In conclusion, vitrification using KYO-1 which is composed of 5.38 m ethylene glycol, 2 m DMSO, 0.1 m PEG 1000 and 0.00175 m PVP K10 in EuroCollins, is a suitable method for cryopreservation of microencapsulated islets.
authors: Department of Regenerative Materials, Institute for Frontier Medical Sciences, Kyoto University, Shogoin, Kyoto, Japan.
authors: Carlos A
authors: CA
authors: Agudelo
authors: Hiroo
authors: H
authors: Iwata
mesh_terms: D000818:Animals; D021522:Bioartificial Organs; D001672:Biocompatible Materials / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006224:Cricetinae; D015925:Cryopreservation; D003451:Cryoprotective Agents; D004121:Dimethyl Sulfoxide; D004339:Drug Compounding; D005260:Female; D005947:Glucose / Q000494:pharmacology; D020100:Hydrogels; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D008422:Materials Testing; D008567:Membranes, Artificial; D008647:Mesocricetus; D019397:Pancreas, Artificial; D011092:Polyethylene Glycols; D012685:Sepharose / Q000737:chemistry; D012996:Solutions; D023822:Tissue Engineering / Q000379:methods
chemical_list: D001672:Biocompatible Materials; D003451:Cryoprotective Agents; D020100:Hydrogels; D007328:Insulin; D008567:Membranes, Artificial; D012996:Solutions; D011092:Polyethylene Glycols; D012685:Sepharose; D005947:Glucose; D004121:Dimethyl Sulfoxide