Angiogenesis and the Extracellular Matrix

描述（由申请人提供）： 这项生物工程研究基金的主要目的是在微观水平上研究血管生成微血管与细胞外基质（ECM）的生物力学相互作用。我们将回答以下问题：血管生成如何影响全球和当地ECM材料的性能和超微结构？局部血管生成发芽与计算力学模型、MMP表达和ECM超微结构预测的应力状态相关吗？血管化结构的机械调节是否影响血管生成发芽？为了回答这些问题，我们将开发和应用新的实验和计算技术来研究3D体外血管生成模型。在第一个具体的目标，我们将开发技术来模拟微尺度的生物力学行为的血管化胶原蛋白凝胶使用材料点方法（MPM），使用体积共聚焦图像作为基础，用于生成的几何计算域。在目标2中，将开发的方法，非破坏性地测量胶原凝胶超微结构，微血管的几何形状和发射光谱，使用荧光光谱和多光子荧光显微镜。在目标3和4中，这些高度新颖的方法将与用于生物力学行为、基因表达和蛋白质表达的实验测量的传统方法相结合，以检查负责血管生成期间ECM材料性质改变的机制。最后，我们将研究机械调节对微血管发芽和生长的影响。拟议的实验将提供一个信息的基础上的力量，最影响血管生成血管的幅度和频率。更好地理解血管生成血管、周围ECM结构和经历血管生成的组织的力学之间的关系将为改善天然组织（例如，修复缺血组织）和组织工程构建体。

DESCRIPTION (provided by applicant): The broad objective of this Bioengineering Research Grant is to study biomechanical interactions of angiogenic microvessels with the extracellular matrix (ECM) on the microscale level. We will answer the following questions: How does angiogenesis influence global and local ECM material properties and ultrastructure? Is local angiogenic sprouting correlated with the stress state as predicted by computational mechanical modeling, MMP expression and ECM ultrastructure? Does mechanical conditioning of vascularized constructs influence angiogenic sprouting? To answer these questions, we will develop and apply novel experimental and computational techniques to study a 3D in vitro angiogenesis model. In the first specific aim, we will develop techniques to simulate the microscale biomechanical behavior of vascularized collagen gels using the Material Point Method (MPM), using volumetric confocal images as the basis for generating the geometry of the computational domain. In Aim 2, methods will be developed to nondestructively measure collagen gel ultrastructure, microvessel geometry and emission spectra using spectrofluorimetry and multiphoton fluorescence microscopy. In Aims 3 and 4, these highly novel approaches will be combined with traditional approaches for experimental measurements of biomechanical behavior, gene expression and protein expression to examine the mechanisms that are responsible for alterations in ECM material properties during angiogenesis. Finally, we will examine the effects of mechanical conditioning on microvessel sprouting and growth. The proposed experiments will provide an information base on the magnitudes and frequencies of forces that most influence the angiogenic vessel. A better understanding of the relationship between angiogenic vessels, the surrounding ECM structure, and the mechanics of the tissue undergoing angiogenesis will provide the basis for improved control of tissue vascularization in both native tissues (e.g., repairing ischemic tissue) and tissue engineered constructs.