A stem cell activated cryogel bioscaffold that restores islet bioenergetics while providing oxygen and nutrients at extravascular sites of transplantation

项目摘要 胰岛移植是一种β细胞替代疗法，用于治疗缺乏分泌能力的糖尿病患者。 胰岛素胰岛移植的常规部位是肝脏，然而，这远不是最佳的， 受到缺氧，有毒代谢物从肝脏，促炎环境和即时血液- 介导的炎症反应（IBMIR）;这导致高达60-70%的胰岛立即丢失 移植后。此外，鉴于胰岛移植不需要创建外科手术， 血管吻合，胰岛因此需要建立和确保专用的血液供应，这至少需要 3周在此期间，胰岛必须依靠氧气和营养物质（如必需的 氨基酸如谷氨酰胺和丙氨酸）从移植部位的微环境中释放，这导致 他们承受着巨大的压力和生物能量的消耗。因此，我们确定了几个关键的 在移植过程中的问题，我们已经解决了我们的创新和临床翻译 在移植过程中和移植后维持胰岛健康和存活的解决方案。最近我们 开发并验证了一种新型胶原基冷冻凝胶3D基质，该基质结合了氧气发生器， 解决氧气不足导致胰岛缺氧的问题。在目标1中，我们将函数化它， 生物支架平台，其具有释放氨基的中孔二氧化硅纳米颗粒形式的营养物发生器 acids.使用这些技术将调节向胰岛释放的氧气和氨基酸，以确保 持续3周以上。考虑到孤立的胰岛受到压力并表现出衰竭，这进一步 在移植后恶化，在目标2中，我们将致力于重新激活胰岛并恢复其功能。 使用骨髓源间充质细胞（BM-MSC）分离后立即的生物能量潜力; 这些细胞可以通过隧道纳米管（TNT）将其健康的线粒体转移到胰岛， 当BM-MSC与胰岛紧密接近时增强-因此，我们将通过以下方式激活我们的生物支架平台 用BM-MSC预接种。在目标3中，我们将测试我们优化的“活性”生物支架恢复 在糖尿病动物模型中，在2个血管外移植部位（即网膜和血管外移植部位）的血糖控制 皮下空间），因为这将减轻胰岛在其递送后通常遇到的IBMIR 通过门静脉进入肝脏在每一个位点，我们将检查我们的活性生物支架是否能 短期炎症反应和异物反应，长期纤维化/包囊化; 我们希望这些反应是最小的，因为我们的生物支架是由胶原蛋白制成的，它们含有BM- 间充质干细胞通过其旁分泌能力具有强效抗炎、免疫调节和抗纤维化作用 释放细胞因子和细胞外囊泡。这些数据将为我们的新药物的未来临床试验铺平道路。 平台，可按GMP准则进行规模化生产。

PROJECT SUMMARY Islet transplantation is a β-cell replacement therapy used to treat diabetic patients who lack the ability to secrete insulin. The conventional site for islet transplantation is the liver, however, this is far from optimal given that islets are subjected to hypoxia, toxic metabolites from the liver, a pro-inflammatory environment and an instant blood- mediated inflammatory reaction (IBMIR); together, this results in up to 60-70% of islets being immediately lost following transplantation. Furthermore, given that islet transplantation does not require the creation of a surgical vascular anastomosis, islets therefore need to build and secure a dedicated blood supply, which takes at least 3 weeks. In the interim, islets have to survive by relying on the diffusion of oxygen and nutrients (such as essential amino acids like glutamine and alanine) from the microenvironment of the transplantation site, which results in them enduring significant stress and bioenergetic depletion. Accordingly, we have identified several critical problems in the transplantation process which we have addressed with our innovative and clinically translatable solution that will maintain islet health and survival, during, and following, their transplantation. Recently, we developed and validated a novel collagen based cryogel 3D matrix that incorporates an oxygen generator to address the problem of insufficient oxygen which causes islet hypoxia. In Aim 1, we will functionalize this bioscaffold platform with a nutrient generator in the form of a mesoporous silica nanoparticle that releases amino acids. The release of both oxygen and amino acids to islets using these technologies will be modulated to ensure it is continuous over 3-weeks. Given isolated islets are stressed and exhibit exhaustion, which is further exacerbated following their transplantation, in Aim 2 we will aim to re-energize islets and restore their bioenergetic potential immediately after isolation using bone marrow derived mesenchymal cells (BM-MSCs); these cells can transfer their healthy mitochondria to islets via tunneling nanotubes (TNTs) and this can be potentiated when BM-MSCs are in close proximity to islets – hence, we will activate our bioscaffold platform by pre-seeding it with BM-MSCs. In Aim 3, we will then test the ability of our optimized “active” bioscaffold to restore glycemic control in diabetic animal models at 2 extra-vascular sites of transplantation (i.e. the omentum and the subcutaneous space) given this will mitigate the IBMIR normally encountered by islets following their delivery into the liver via the portal vein. At each of these sites, we will examine whether our active bioscaffold elicits an inflammatory response and foreign body reaction in the short term, and fibrosis/encapsulation in the long term; we expect these responses to be minimal given our bioscaffolds are made from collagen and they contain BM- MSCs that have potent anti-inflammatory, immunomodulatory and anti-fibrotic effects via their paracrine ability to release cytokines and extracellular vesicles. This data will pave the way for future clinical trials with our novel platform which can be scaled and produced conforming to GMP guidelines.