Human Islet Viability and Function Is Maintained During High-density Shipment in Silicone Rubber Membrane Vessels

Abstract

The shipment of human islets from processing centers to distant laboratories is beneficial for both research and clinical applications. The maintenance of islet viability and function in transit is critically important. Gas-permeable silicone rubber membrane (SRM) vessels reduce the risk of hypoxia-induced death or dysfunction during high-density islet culture or shipment. SRM vessels may offer additional advantages: they are cost-effective (fewer flasks, less labor needed), safer (lower contamination risk), and simpler (culture vessel can also be used for shipment). Human islets(IE) were isolated from two manufacturing centers and shipped in 10cm2 surface area SRM vessels in temperature and pressure controlled containers to a distant center following at least two days of culture (n = 6). Three conditions were examined: low density (LD), high density (HD), and a micro centrifuge tube negative control (NC). LD was designed to mimic the standard culture density for human islet preparations (200 IE/cm2), while HD was designed to have a 20-fold higher tissue density, which would enable the culture of an entire human isolation in 1–3 vessels. Upon receipt, islets were assessed for viability, measured by oxygen consumption rate normalized to DNA content (OCR/DNA), and quantity, measured by DNA, and, when possible, potency and function with dynamic glucose-stimulated insulin secretion (GSIS) measurements and transplants in immunodeficient B6 rag mice. Post-shipment OCR/DNA was not reduced in HD versus LD, and was substantially reduced in the NC condition. HD islets exhibited normal function post-shipment. Based on the data we conclude that entire islet isolations (up to 400,000 IE) may be shipped using a single, larger SRM vessel with no negative effect on viability and ex vivo and in vivo function.

Mitigating hypoxic stress on pancreatic islets via in situ oxygen generating biomaterial

“…During the pre-transplant culture period, islets are exposed to detrimental oxygen gradients that can result in significant declines in viability and function [36]. To fully alleviate these gradients using standard culture dishes would require the application of impractical culture methods [36, 37]. While advancements have been made in modifying culture flasks to enhance oxygen permeability [37], the implementation of in situ oxygen generators has the potential to heighten the viability of islet tissue and provide a more practical and cost effective method for improving in vitro culture, as oxygen supplementation could be tailored to the cellular demand of the tissue.…”

“…To fully alleviate these gradients using standard culture dishes would require the application of impractical culture methods [36, 37]. While advancements have been made in modifying culture flasks to enhance oxygen permeability [37], the implementation of in situ oxygen generators has the potential to heighten the viability of islet tissue and provide a more practical and cost effective method for improving in vitro culture, as oxygen supplementation could be tailored to the cellular demand of the tissue. As it relates to transplant outcomes, these materials could be conveniently translated in vivo ; providing local and controlled augmented oxygen.…”

In vitro characterization of neonatal, juvenile, and adult porcine islet oxygen demand, β‐cell function, and transcriptomes

“…This method has previously been demonstrated to maintain islet viability and function during shipment. 34 Following receipt, all islets were cultured at 37°C for 24 hours prior to assessment. Neonatal Porcine Islets: NPI were isolated in the Korbutt laboratory and cultured as previously published.…”

Use of additives, scaffolds and extracellular matrix components for improvement of human pancreatic islet outcomes in vitro: A systematic review

“…All studies included in this systematic review used the Ricordi's semi-automated technique for islet isolation. 54 Twenty-three studies (62.2%) used CRML 1066 as the islet culture media after isolation, 16,17,19,24,25,27,[32][33][34][35][37][38][39][41][42][43][47][48][49][50][51][52][53] 4 studies used Miami media, 22,23,29,30 3 used M199 media, 21,31,44 6 of them did not report the media used, 18,26,28,36,40,45 and one study used Ham's/F10 media. 46 All studies had an experimental group where modifications Table 1.…”