(335m) Experimental Evaluation of Quadrupole Magnetic Flow Sorter for Pancreatic Islets

Diabetes, a group of metabolic diseases affecting 8 per cent of the US population, costs the US economy more than $132 billion per year. Insulin treatment cannot fully prevent chronic complications, and intensive insulin treatment to improve metabolic control is paralleled by an increased risk of severe hypoglycemia. Pancreatic islet transplantation offers a viable option to achieve permanent metabolic control in Type 1 diabetes patients. However, large quantities of pure viable donor islet cells are necessary for transplantation. Using currently available islet isolation methods multiple donor organs are required to achieve successful transplantation, and there is a demand for an isolation method with high islet yield and viability.

Quadrupole Magnetic Sorting (QMS), a single cell separation method, is being modified for the isolation of pancreatic islets. QMS is a split flow thin channel form of continuous separation device, which consists of two substantial components: an automated processing system that contains a high energy density Halbach quadrupole magnet assembly and a disposable annular flow channel capable of providing the fluid transport to separate the magnetically labeled cells. Islets or surrogate islets are labeled with 4.6µm Dynal Dynabeads® and separated continuously with QMS. Studies of pancreatic digests with the modified flow channel indicate high purities with less than 2 per cent crossover of acinar tissue into the magnetic fraction. In the parallel flow streams of QMS islets are rapidly removed from the harmful enzymes and competing acinar tissue in the digest fluid. Presence of Dynabeads® in the islets after the isolation does not affect the islet functionality. QMS subjects islets to less mechanical and chemical stress when compared to other separation techniques like density gradient methods, potentially increasing the number of islets that survive transplantation.

Keywords: magnetic flow sorter, pancreatic islets, magnetic particles, diabetes

This research is supported by National Institute for Diabetes and Digestive and Kidney Disease Research, grant SR44DK.