Direct effect of alginate purification on the survival of islets immobilized in alginate-based microcapsules
Direct effect of alginate purification on the survival of islets immobilized in alginate-based microcapsules
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DOI：
10.1016/j.actbio.2009.05.029
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发表时间：
2009-11-01
影响因子：
9.7
通讯作者：
Halle, Jean-Pierre
中科院分区：
文献类型：
--
作者：
Langlois, Genevieve;Dusseault, Julie;Halle, Jean-Pierre
海藻酸盐纯化已被证明可以降低宿主对植入的海藻酸盐微胶囊的免疫反应，但污染物对胰岛细胞存活的直接影响仍然未知。将 Wistar 大鼠胰岛固定在用粗海藻酸盐与纯化海藻酸盐制成的海藻酸钙珠中，然后在 CMRL 培养基中孵育。在封装后第 1、4、7、14 和 27 天评估胰岛存活率。使用双染色测定（碘化丙啶和橙色吖啶）研究胰岛活力。分别在光学显微镜下和 TUNEL 测定中对胰岛细胞坏死和凋亡细胞的比例进行定量。固定在纯化海藻酸盐中的胰岛活力更高，坏死中心更少，中央坏死面积更小，凋亡细胞数量更少。在封装后第 14 天和 27 天，使用纯化海藻酸盐的胰岛分别有 48% 和 23% 存活，而使用粗海藻酸盐的胰岛存活率为 18% 和 8%（p < 0.05）。第 14 天时，不纯藻酸盐的中心坏死表面积和坏死胰岛数量更为重要（分别为 65% vs. 45% 和 73% vs. 53%；p < 0.05）。我们得出的结论是，藻酸盐纯化可提高固定在藻酸盐微胶囊中的胰岛的存活率。这些发现表明，在解释体内实验时应谨慎，因为结果可以通过对胰岛存活的直接影响或宿主反应的改变或两者来解释。此外，它表明在开发用于细胞封装的生物材料期间应评估对胰岛活力的影响。 (C) 2009 Acta Materialia Inc. 由 Elsevier Ltd 出版。保留所有权利。
Alginate purification has been shown to decrease the host immune response to implanted alginate-based microcapsules, but the direct effect of contaminants on islet cell survival remains unknown. Wistar rat islets were immobilized in calcium alginate beads made with crude vs. purified alginate and then incubated in CMRL culture medium. Islet survival was evaluated at 1, 4, 7, 14 and 27 days post-encapsulation. Islet viability was investigated using a dual staining assay (propidium iodide and orange acridine). The islet cell necrosis and the proportion of apoptotic cells were quantified under optical microscopy and with a TUNEL assay, respectively. Islets immobilized in purified alginate were more viable, and had fewer necrotic centers, a smaller area of central necrosis and a lower number of apoptotic cells. At day 14 and 27 post-encapsulation, respectively, 48% and 23% of islets were viable with purified alginate vs. 18% and 8% with crude alginate (p < 0.05). At day 14, the surface area of central necrosis and the number of necrotic islets were more important with the impure alginate (65% vs. 45% and 73% vs. 53%, respectively; p < 0.05). We conclude that alginate purification improves the survival of islets that are immobilized in alginate-based microcapsules. These findings indicate that caution should be taken in the interpretation of in vivo experiments, as the results could be explained by either a direct effect on islet survival or a modification of the host reaction, or both. Moreover, it suggests that the effect on islet viability should be assessed during the development of biomaterials for cell encapsulation. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.