Iodixanol-Controlled Density Gradient During Islet Purification Improves Recovery Rate in Human Islet Isolation

Abstract

Our data suggest that using an iodixanol-controlled density gradient improves the islet recovery rate in human islet isolation. On the basis of these data, we now use this purification method for clinical islet transplantation.

Recent progress in pancreatic islet transplantation

“…The islet yield after purification and the post-purification recovery rate was significantly higher when the controlled density gradient purification method was used than when using the standard continuous gradient purification by Ficoll solutions. The percentage of islets recovered from the controlled-density solution was approximately 80% [35] . Another group also showed the effectiveness of controlled-density gradients using a continuous gradient for the density determination step [36] .…”

“…The percentage of islets recovered from a standard Ficoll purification has been reported to range from 55%-65% [33,34] . We recently showed the effectiveness of controlled-density gradients using iodixanol [35] . According to the outcome of the density determination step, the density of the purification solutions was controlled (low density, 1.075 g/cm 3 ; high density, 1.085-1.110 g/cm 3 ) by changing the volumetric ratio of iodixanol and the purification solutions.…”

Tissue Engineering for Tissue and Organ Regeneration

“…However, the drawbacks of the Edmonton protocol include necessity of multiple donor organs, unstable islet isolation results, necessity of immunosuppressive drugs, difficulty of maintaining long-term insulin independence and severe shortage of donor organs . Currently, we introduced new pancreas preservation (Matsumoto et al, 2002a(Matsumoto et al, , 2002b(Matsumoto et al, , 2010b and islet isolation strategies (Noguchi et al, 2009a;Shimoda et al, 2010) and immunosuppressive therapy to improve the efficacy of islet isolation . Now, we have a very stable islet isolation method, in addition, a single donor pancreas is enough to achieve insulin independence .…”

Encapsulated islets transplantation: Past, present and future

“…Digested pancreas contains many exocrine and connective tissues that may cause portal vein hypertension and thrombosis; thus, removing these cellular components is necessary. Purification is performed using a COBE 2991 cell processor with Ficoll or iodixanol gradient solution [15] . Obtaining many good islets from the donor pancreas is necessary to cure severe diabetes, but it is impossible to obtain all islets contained in the pancreas by current isolation techniques.…”