Biomimetic Materials and Bioprocesses for High-Density Cultures of Pancreatic Islets and Tissues

350万加拿大人患有糖尿病，相关成本为34亿美元。在1型和2型糖尿病中都观察到了β细胞(产生胰岛素的细胞)丢失。胰岛移植可以恢复胰岛β细胞功能，使1型糖尿病患者血糖正常。胰岛移植遇到了包括β细胞凋亡在内的问题。提高胰岛移植的成功率一直是研究界关注的目标。此外，制药公司已经确定，由于缺乏足够的胰腺组织模型，治疗糖尿病的治疗方法的开发受到阻碍。 组织工程学方法已被应用于将胰岛和胰岛β细胞包裹和培养在三维基质中，并使用生物反应器。这里的目的是将细胞/组织暴露在模拟其本地环境的环境中，以便它们能够更具生理学的行为。囊化胰岛可能是保护移植胰岛免受宿主反应的一种解决方案。组织工程学的发展使脱细胞器官和组织能够用作细胞治疗的支架。然而，人们对脱细胞基质对细胞的影响机制知之甚少。 该项目的长期目标是开发自动化流程，以高密度分离和培养胰腺内分泌组织和细胞，并使该流程适用于其他组织和器官。 具体目标是： 1)研制一种用于器官/组织脱细胞的灌注式生物反应器，以及用于细胞/组织接种和培养的方法。该反应器将用于研究胰岛和胰岛β细胞在去细胞器官和组织中的存活和功能； 2)研究内分泌胰岛/细胞在脱细胞组织/器官仿生表面上的存活和功能； 3)研究生物反应器灌流条件下内分泌胰岛细胞与胰腺微血管共培养的特性。 意义和新颖性：1)我们的仿生表面提供了出色的低污染涂层，允许通过消除非特定细胞响应来研究特定细胞响应。2)关于仿生支架如何影响胰岛的知识可以支持开发更好的封装技术。3)了解血流条件如何影响胰岛反应，有助于确定移植的胰岛如何受到植入部位生理条件的影响。开发一种自动化的器官/组织脱细胞工艺，将是将人工操作的实验室规模的方法转变为细胞治疗产品的工业工艺的一步。4)最后，关于如何在孤立的胰岛中重建功能性血管系统，人们知之甚少。我们是第一个分离胰腺微血管的人。该计划将支持高素质人才的培训。

3.5 million Canadians live with diabetes, with an associated cost of $ 3.4 billion. Beta-cells (cells producing insulin) lost has been observed in both types 1 and 2 diabetes. Pancreatic islet transplantation can restore functional beta-cells to achieve normoglycemia in type 1 diabetics. Islet transplantation has encountered problems including beta-cell apoptosis. Improving the success of islet transplantation has been a target in the research community. Also, the development of therapeutic to treat diabetes has been identified by pharmaceutical companies to be hindered due to a lack of adequate pancreatic tissue models. Tissue engineering methods have been applied to encapsulate and culture pancreatic islets and beta-cells in three-dimensional matrices, and using bioreactors. The aim here is to expose cells/tissues to environments mimicking their native ones, so they can behave more physiologically. Encapsulating pancreatic islets could be a solution to protect transplanted islets from host responses. Development in tissue engineering enables the use of decellularized organs and tissues as scaffolds for cell therapies. However, little is known about the mechanisms governing the effects of decellularized matrices on cells. The LONG-TERM PROGRAM OBJECTIVE is to develop the automated processes to isolate and culture endocrine pancreatic tissues and cells at high density and to adapt the process to other tissues and organs. The SPECIFIC OBJECTIVES are: 1) To develop a perfusion bioreactor for organ/tissue decellularization and processes for cell/tissue seeding and culture. This reactor will be used to investigate pancreatic islets and beta-cells survival and function in decellularized organs and tissues under perfusion; 2) To study endocrine pancreatic islets/cells survival and function on biomimetic surfaces produced from decellularized tissues/organs; 3) To characterize the co-culture of endocrine pancreatic islets and cells with pancreatic microvessels under bioreactor perfusion. SIGNIFICANCE AND NOVELTY: 1) Our biomimetic surfaces provide excellent low-fouling coatings allowing studying specific cell responses by eliminating non-specific ones. 2) Knowledge about how biomimetic scaffolds affect islets can support the development of better encapsulation techniques. 3) Understanding how flow conditions affect islet responses allows identifying how transplanted islets are affected by physiological conditions at an implantation site. Developing an automated process to decellularize organs/tissues will be a step to transfer manually-operated laboratory-scale methods to industrial processes for cell therapy products. 4) Finally, little is known about how to re-establish a functional vasculature in isolated islets. We have been the first to isolate pancreatic microvessels. This program will support training of highly qualified personnel.