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

项目总结 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。胰岛移植的传统部位是肝脏，然而，考虑到胰岛，这远远不是最理想的。 会受到缺氧、肝脏有毒代谢物、促炎环境和瞬间血液的影响- 介导性炎症反应(IBMIR)；加在一起，高达60%-70%的胰岛立即消失 在移植后。此外，鉴于胰岛移植不需要创建外科手术 血管吻合，因此胰岛需要建立和确保专门的血液供应，这至少需要 3周。在此期间，小岛必须依靠氧气和营养物质(如必需的)的扩散来生存 氨基酸，如谷氨酰胺和丙氨酸)，这导致 它们承受着巨大的压力和生物能量的消耗。因此，我们已经确定了几个关键的 移植过程中的问题，我们已经用我们的创新和临床可翻译的 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的胶原基冷冻胶3D基质，它包含一个氧气发生器来 解决导致胰岛缺氧的氧气不足问题。在目标1中，我们将实现这一点 具有释放氨基的介孔二氧化硅纳米颗粒形式的营养生成器的生物支架平台 酸。使用这些技术的胰岛的氧气和氨基酸的释放将得到调节，以确保 它是连续的，超过3周。由于孤立的胰岛受到压力并表现出精疲力竭，这进一步 在移植后情况恶化，在目标2中，我们将致力于重新激活胰岛并恢复其 骨髓间充质干细胞(BM-MSCs)分离后即刻的生物能潜能； 这些细胞可以通过隧道纳米管(TNTs)将其健康的线粒体转移到胰岛，这可以 当BM-MSCs靠近胰岛时增强-因此，我们将通过以下方式激活我们的生物支架平台 预先接种骨髓间充质干细胞。在目标3中，我们将测试我们优化的“活性”生物支架修复的能力 糖尿病动物模型移植血管外2个部位的血糖控制 皮下间隙)，因为这将减轻胰岛分娩后通常遇到的IBMIR 通过门静脉进入肝脏。在每个地点，我们将检查我们的活性生物支架是否会引起 短期炎性反应和异物反应，长期纤维化/包膜； 我们预计这些反应是最小的，因为我们的生物支架是由胶原蛋白制成的，而且它们含有BM- MSCs通过旁分泌能力具有强大的抗炎、免疫调节和抗纤维化作用 释放细胞因子和细胞外小泡。这些数据将为我们的新书未来的临床试验铺平道路 可根据GMP指南进行规模和生产的平台。

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.