DEVELOPMENT OF AN AUTOMATED COMPUTER-CONTROLLED ISLET ISOLATION SYSTEM

Before clinical islet transplantation can become an effective and reli able treatment for type I diabetic patients, there must be significant improvements in the methods employed for the isolation of islets of L angerhans, We have developed an automated cell extraction system (AGES ), which allows computer control of the isolation process, As well, it incorporates a novel method of recombining dissociated pancreatic tis sue, Following initial system design and testing to determine the opti mal system configuration, a series of 12 consecutive canine islet isol ations mere performed, Pancreases were perfused with collagenase via t he duct and dissociated and recombined using either the standard Ricor di-based protocol (group 1, n = 6) or dissociated and recombined using the AGES system (group 2, n = 6), A total of 90.8 +/- 21 x 10(3) isle t equivalents (IE) (mean +/- SEM) were recovered in group 1 vs. 99 +/- 14 x 10(3) IE in group 2 (p = NS, student unpaired t-test), Following Ficoll purification the recovery mas 56.2 +/- 14 x 10(3) IE for group 1 vs, 54.7 +/- 11 x 10(3) IE for group 2 (p = NS). Viability was equi valent with an 8.6-fold increase in insulin secretion for group 1 and an 8.8-fold increase for group 2 when the islets were exposed to high glucose solution supplemented with IBMX (3-isobutyl-1-methylxanthine) during static incubation, In vivo function was equivalent following tr ansplantation of 2000 IE under the kidney capsule of alloxan-induced d iabetic nude mice with five of six and five of seven mice surviving lo ng-term (>50 days posttransplant) (groups 1 and 2, respectively), This data shows that an entirely automated pancreatic islet extraction sys tem can result in effective canine islet recovery without compromising islet yields and viability, The AGES system has several advantages ov er the standard isolation protocol. These include: 1) computer control and monitoring over all phases of the isolation, 2) a single-use ster ile disposable tubing set, and 3) novel method of tissue recombination . Copyright (C) 1997 Elsevier Science Inc.