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 -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. 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. 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.