(Re)vascularization of decellularized scaffolds

项目摘要 脱细胞器官作为大型可移植器官工程的支架具有巨大的前景。 移植物实现这一愿景将需要一种方法来重建功能血管树在这样的支架。 这项试验性R03研究的目的是应用我们从血管化微流体中学到的经验教训， 胶原和纤维蛋白基凝胶，对血管化的脱细胞支架。我们之前的研究表明 物理信号在促进功能性血管形成中的主导地位。令人惊讶的是，物理信号 在脱细胞支架中很少被研究为血管化的潜在促进剂，我们 他们认为，它们可能是获得持久的、功能性血管网络所需的缺失成分。 拟议的工作将使用脱细胞毛细血管和微血管的体外模型， 筛选血管化条件，以先前确定的物理信号为起点。最 在这些筛选中鉴定的有希望的条件将在脱细胞的大鼠脂肪垫和离体肺上进行测试。 生理学和组织学分析，重点是内皮屏障的完整性，将提供 血管功能的器官水平和微观尺度测量。血管化支架将被植入 在大鼠中原位进行，以确定体内血管的功能。完成后，拟议的工作 将产生原理性的再血管化的器官规模的支架， 移植物，用于最终生成血管化的功能器官。

PROJECT SUMMARY Decellularized organs hold tremendous promise as scaffolds for the engineering of large transplantable grafts. Achieving this vision will require a method to reconstruct functional vascular trees within such scaffolds. The objective of this pilot R03 study is to apply the lessons we have learned from vascularizing microfluidic collagen- and fibrin-based gels, towards the vascularization of decellularized scaffolds. Our prior studies point toward the dominance of physical signals in promoting functional vascularization. Surprisingly, physical signals have rarely been examined as potential promoters of vascularization in decellularized scaffolds, and we believe they may be the missing ingredient needed to obtain durable, functional vascular networks. The proposed work will use in vitro models of decellularized capillaries and microvessels to quickly screen vascularization conditions, with previously identified physical signals as a starting point. The most promising conditions identified in these screens will be tested on decellularized rat fat pads and lungs ex vivo. Physiological and histological analyses, with emphasis on integrity on the endothelial barrier, will provide organ-level and microscale measures of vascular function. Vascularized scaffolds will be implanted orthotopically in the rat to determine the functionality of the vessels in vivo. At completion, the proposed work will yield proof-of-principle revascularized organ-scale scaffolds that are ready to accept parenchymal cell grafts, for the eventual generation of vascularized functional organs.