Filtration is a time-efficient option to Histopaque, providing good-quality islets in mouse islet isolation

Abstract

Pancreatic islet transplantation is a promising therapy for Type I Diabetes. For many years the method used worldwide for islet purification in both rodent and human islet isolation has been Ficoll-based density gradients, such as Histopaque. However, it is difficult to purify islets in laboratories with staff limitations when large scale isolations are required. We hypothesized that filtration could be a more simple and fast alternative to obtain good quality islets. Four separate islet isolations were performed per method, comparing filtration and Histopaque purification with handpicking as the gold standard method for islet purity. Different parameters of quality were assessed: yield in number of islets per pancreas, purity by dithizone staining, viability by Fluorescein Diacetate/ Propidium Iodide vital staining and in vitro functionality assessed by Glucose Stimulated Insulin Secretion. Time efficiency and cost were also analyzed. The overall quality of the islets obtained both by Histopaque and filtration was good. Filtration saved almost 90 % of the time consumed by Histopaque purification, and was also cheaper. However, one-third of the islets were lost. Since human and rodent islets share similar size but different density, filtration appears as a purification method with potential interest in translation to clinic.

“Old School” Islet Purification Based on the Unit Gravity Sedimentation as a Rescue Technique for Intraportal Islet Transplantation—A Case Report

“…Therefore, we called it “old school” purification 18 . Many purification methods have been subsequently tested including hand-picking 19 , phototermolysis 20 , radiation 21 , osmolality-dependent isolation 22 , cryo-isolation, 23 and cell sorting 24 . However, most of these methods have only been used in research settings.…”

Though Active on RINm5F Insulinoma Cells and Cultured Pancreatic Islets, Recombinant IL-22 Fails to Modulate Cytotoxicity and Disease in a Protocol of Streptozotocin-Induced Experimental Diabetes

“…Islets were isolated by density gradient centrifugation using Ficoll Paque Plus (GE Healthcare, München, Germany), were washed, and handpicked thereafter. Isolation by combined density gradient centrifugation and subsequent handpicking as performed herein results in highly pure cultures with islet purity >99% ( Ramírez-Domínguez and Castaño, 2015 ). After 48–96 h recovery in aforementioned medium, 60–100 islets (as specified in the respective figure legends) were seeded on 12-well polystyrene plates (Greiner, Frickenhausen).…”

The potential of the incorporated collagen microspheres in alginate hydrogel as an engineered three-dimensional microenvironment to attenuate apoptosis in human pancreatic islets

“…To examine the effect of scaffolds on pancreatic islets viability after one week, fluorescent dyes (Sigma, Germany) were applied (17). In this regard 5mg/ml fluorescein diacetate (FDA) and 2mg/ml propidium iodide (PI) were used to detect the live and dead cells, respectively.…”