Department of Surgery, University of California Irvine, Orange, CA, USA.
Department of Biomedical Engineering, University of California Irvine, Orange, CA, USA.
Xenotransplantation. 2020 Jan;27(1):e12554. doi: 10.1111/xen.12554. Epub 2019 Sep 8.
Islet recovery from within alginate-based microcapsules is necessary for certain analytical assays like flow cytometry; however, this technology has not been widely characterized. In this study, we explore the ability of EDTA, EGTA, and sodium citrate to induce reverse alginate polymerization via chelation and assess the toxicity of each chelator on pancreatic islets.
EDTA, EGTA, and sodium citrate were used to dissolve single-layered Ba alginate encapsulated islets and the rate of capsule breakdown calculated from analysis of imaging data. The effect of chelator exposure on islet viability and recovery was assessed using flow cytometry, while glucose-stimulated insulin release (GSIR) assay was used to measure effects on islet function.
EGTA demonstrated the most rapid microcapsule dissolving rate followed by EDTA and sodium citrate. Islet recovery was significantly better when encapsulated islets were treated with EDTA than EGTA and Na citrate. A decrease in viability and increase in apoptotic cells were observed when encapsulated islets were treated with Na citrate compared to islets treated with EDTA and EGTA. Islets treated with EDTA and EGTA demonstrated comparable stimulation index values to non-treated control. Conversely, islets treated with Na citrate exhibited significantly decreased SI values compared to control. All chelator groups showed significantly lower insulin secretion than non-treated islets.
Islet recovery from alginate microcapsule is possible using common chelators like Na citrate, EDTA, and EGTA. Chelation of encapsulated islets using EDTA demonstrated the most efficient dissolving capabilities with the least toxicity toward islet recovery and health.
从基于藻酸盐的微胶囊中回收胰岛对于某些分析测定（如流式细胞术）是必要的；然而，这项技术尚未得到广泛的描述。在这项研究中，我们探索了 EDTA、EGTA 和柠檬酸钠通过螯合诱导藻酸盐反向聚合的能力，并评估了每种螯合剂对胰岛的毒性。
使用 EDTA、EGTA 和柠檬酸钠溶解单层 Ba 藻酸盐包被的胰岛，并从成像数据分析中计算胶囊破裂的速率。通过流式细胞术评估螯合剂暴露对胰岛活力和恢复的影响，同时使用葡萄糖刺激胰岛素释放（GSIR）测定来测量对胰岛功能的影响。
EGTA 显示出最快的微胶囊溶解速率，其次是 EDTA 和柠檬酸钠。与 EGTA 和 Na 柠檬酸盐相比，用 EDTA 处理的包被胰岛的胰岛回收率明显更好。与用 EDTA 和 EGTA 处理的胰岛相比，用 Na 柠檬酸盐处理的胰岛的活力下降，凋亡细胞增加。用 EDTA 和 EGTA 处理的胰岛与未处理的对照胰岛具有可比的刺激指数值。相反，用 Na 柠檬酸盐处理的胰岛与对照相比，SI 值显著降低。所有螯合剂组的胰岛素分泌均明显低于未处理的胰岛。
使用常见的螯合剂（如 Na 柠檬酸盐、EDTA 和 EGTA）从藻酸盐微胶囊中回收胰岛是可能的。用 EDTA 螯合包被的胰岛显示出最有效的溶解能力，对胰岛恢复和健康的毒性最小。
