S A Fernandez, K S Champion, L Danielczak, M Gasparrini, S Paraskevas, R L Leask, C A Hoesli
Department of Chemical Engineering, McGill University, Montréal, QC, Canada.
Human Islet Transplant Laboratory, McGill University Health Centre, Montréal, QC, Canada.
Front Bioeng Biotechnol. 2022 Apr 19;10:884071. doi: 10.3389/fbioe.2022.884071. eCollection 2022.
Islet encapsulation devices serve to deliver pancreatic beta cells to type 1 diabetic patients without the need for chronic immunosuppression. However, clinical translation is hampered by mass transport limitations causing graft hypoxia. This is exacerbated in devices relying only on passive diffusion for oxygenation. Here, we describe the application of a cylindrical perfusion system to study oxygen effects on islet-like clusters immobilized in alginate hydrogel. Mouse insulinoma 6 islet-like clusters were generated using microwell plates and characterized with respect to size distribution, viability, and oxygen consumption rate to determine an appropriate seeding density for perfusion studies. Immobilized clusters were perfused through a central channel at different oxygen tensions. Analysis of histological staining indicated the distribution of viable clusters was severely limited to near the perfusion channel at low oxygen tensions, while the distribution was broadest at normoxia. The results agreed with a 3D computational model designed to simulate the oxygen distribution within the perfusion device. Further simulations were generated to predict device performance with human islets under and conditions. The combination of experimental and computational findings suggest that a multichannel perfusion strategy could support viability and function of a therapeutic islet dose.
胰岛封装装置旨在将胰岛β细胞输送给1型糖尿病患者，而无需长期免疫抑制。然而，临床转化受到传质限制的阻碍，导致移植物缺氧。在仅依靠被动扩散进行氧合的装置中，这种情况会更加严重。在这里，我们描述了一种圆柱形灌注系统的应用，以研究氧气对固定在海藻酸盐水凝胶中的胰岛样簇的影响。使用微孔板生成小鼠胰岛素瘤6胰岛样簇，并对其大小分布、活力和耗氧率进行表征，以确定灌注研究的合适接种密度。固定的簇在不同氧张力下通过中央通道进行灌注。组织学染色分析表明，在低氧张力下，存活簇的分布严重局限于灌注通道附近，而在常氧下分布最广。结果与旨在模拟灌注装置内氧气分布的三维计算模型一致。进一步的模拟被用来预测在不同条件下人类胰岛的装置性能。实验和计算结果的结合表明，多通道灌注策略可以支持治疗性胰岛剂量的活力和功能。
