Modified method of human islet isolation and purification for clinical transplantation

Objective To investigate the methods of islet isolation and purification to get more islet cells with high purity and good function for clinical transplantation. Methods Human pancreas was digested with Liberase HI.The improved Recordi’s automated islet isolation system was used,followed by purification in a Ficoll continuous gradient centrifugation using Cobe 2991 cell separator.After purification,the islet cell yield and purity was evaluated with microscope by DTZ staining,and the activity was evaluated with fluorescence microscope by AO-PI staining.The islet’s function was assessed by insulin release assay in vitro.Results Thirty pancreases were isolated.After purification,an average of(316626±191972)islet equivalents(IEQ)was obtained from each pancreas,with an average purity of(74.7±7.84)﹪and viabiling of(94.1±2.19)﹪The islets responded wellto glucose stimulation with a 3.68-fold increase of insulin secretion over the basal level. Seven patients with type 1 diabetes accepted islet transplantation with expected outcomes. Conclusion The improved Recordi’s automated islet isolation system can provide more high-purity islet cells for clinical transplantation.