title: Continuous Quadrupole Magnetic Separation of Islets during Digestion Improves Purified Porcine Islet Viability.
abstract: Islet transplantation (ITx) is an emerging and promising therapy for patients with uncontrolled type 1 diabetes. The islet isolation and purification processes require exposure to extended cold ischemia, warm-enzymatic digestion, mechanical agitation, and use of damaging chemicals for density gradient separation (DG), all of which reduce viable islet yield. In this paper, we describe initial proof-of-concept studies exploring quadrupole magnetic separation (QMS) of islets as an alternative to DG to reduce exposure to these harsh conditions. Three porcine pancreata were split into two parts, the splenic lobe (SPL) and the combined connecting/duodenal lobes (CDL), for paired digestions and purifications. Islets in the SPL were preferentially labeled using magnetic microparticles (MMPs) that lodge within the islet microvasculature when infused into the pancreas and were continuously separated from the exocrine tissue by QMS during the collection phase of the digestion process. Unlabeled islets from the CDL were purified by conventional DG. Islets purified by QMS exhibited significantly improved viability (measured by oxygen consumption rate per DNA,p< 0.03) and better morphology relative to control islets. Islet purification by QMS can reduce the detrimental effects of prolonged exposure to toxic enzymes and density gradient solutions and substantially improve islet viability after isolation.
authors.affiliation: CMRR, Department of Radiology, University of Minnesota, Minneapolis, MN, USA; Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Bradley P
authors.identifier: 0000-0002-2148-8979
authors.initials: BP
authors.lastname: Weegman
authors.affiliation: Department of Chemical Engineering, Auburn University, Auburn, AL, USA.
authors.forename: Venkata Sunil
authors.initials: VS
authors.lastname: Kumar Sajja
authors.affiliation: Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Thomas M
authors.identifier: 0000-0002-3515-8807
authors.initials: TM
authors.lastname: Suszynski
authors.affiliation: Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Rizzari
authors.affiliation: Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN, USA; Department of Surgery, University of Arizona, Tucson, AZ, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Scott Iii
authors.affiliation: Department of Surgery, University of Arizona, Tucson, AZ, USA.
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Kitzmann
authors.affiliation: Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN, USA; Department of Surgery, University of Arizona, Tucson, AZ, USA.
authors.forename: Kate R
authors.identifier: 0000-0002-8638-365X
authors.initials: KR
authors.lastname: Mueller
authors.affiliation: Department of Chemical Engineering, Auburn University, Auburn, AL, USA.
authors.forename: Thomas R
authors.identifier: 0000-0003-4465-202X
authors.initials: TR
authors.lastname: Hanley
authors.affiliation: MobileMedTek Inc., Louisville, KY 40206, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Kennedy
authors.affiliation: Techshot, Inc., Greenville, IN, USA.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Todd
authors.affiliation: Clinical Islet Cell Laboratory, Cardiovascular Innovation Institute, Department of Surgery, University of Louisville, Louisville, KY 40202, USA.
authors.forename: Appakalai N
authors.initials: AN
authors.lastname: Balamurugan
authors.affiliation: Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Bernhard J
authors.initials: BJ
authors.lastname: Hering
authors.affiliation: Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN, USA; Department of Surgery, University of Arizona, Tucson, AZ, USA.
authors.forename: Klearchos K
authors.identifier: 0000-0002-4554-0911
authors.initials: KK
authors.lastname: Papas
mesh_terms: D000818:Animals; D002499:Centrifugation, Density Gradient; D007515:Islets of Langerhans; D016381:Islets of Langerhans Transplantation; D059346:Magnets; D013552:Swine