Synthesis and Characterization of Patterned Microvascular Networks

描述（由申请人提供）：本5年计划将开发体外合成功能性微血管网络的方法。这项工作的核心是：1）使用光刻法产生具有人微血管床形状的开放内部拓扑结构的三维（3D）构建体，和2）通过培养条件（剪切应力、内腔压力、氧化应激和基质蛋白水解活性）的顺序优化使合成结构成熟。为圆柱形微血管的成熟而定制的条件，其中流动轮廓很容易确定，将作为具有非圆形横截面的微加工通道和网络成熟的起点。这项工作将提供培养条件，增强2个特征性微血管功能（屏障功能和对细胞因子的反应性）的发展，并将确定这些功能在体外共存的程度。这些行为的出现和组织学变化之间的时间相关性将建议进一步促进成熟的策略。这项工作还将确定微血管网络如何重塑（即，它们的横截面形状和网络拓扑结构如何随时间变化），并将提出在连续灌注存在下保持其初始拓扑结构的3D网络的设计原则。更一般地说，这项工作将说明组织工程的光刻方法的独特能力。短期内，这些网络将作为人类血管组织的替代品，用于高通量筛选可能扰乱或增强微血管功能的药物。从长远来看，工程化的网络可以增强体外人工组织的灌注，从而克服组织工程中的主要障碍之一。

DESCRIPTION (provided by applicant): This 5-year proposal will develop methods to synthesize functional microvascular networks in vitro. Central to this work are: 1) the use of lithography to generate three-dimensional (3D) constructs that have open internal topologies in the shape of human microvascular beds, and 2) maturation of as-synthesized structures by sequential optimization of culture conditions (shear stress, lumenal pressure, oxidative stress, and matrix proteolytic activity). Conditions tailored for maturation of cylindrical microvessels, in which the flow profile is easily determined, will serve as a starting point for maturation of microfabricated channels and networks that have non-circular cross-sections. This work will provide culture conditions that enhance the development of 2 characteristic microvascular functions (barrier function and reactivity to cytokines) and will determine to what extent these functions may co-exist in vitro. Temporal correlation between the emergence of these behaviors and changes in histology will suggest strategies to further enhance maturation. This work will also determine how microvascular networks remodel (i.e., how their cross-sectional shapes and network topologies change over time), and will suggest design principles for 3D networks that preserve their initial topologies in the presence of continuous perfusion. More generally, this work will illustrate the unique capabilities of a lithographic approach to tissue engineering. In the short-term, these networks will serve as surrogate human vascular tissues for high-throughput screening of drugs that may perturb or enhance microvascular function. In the long-term, engineered networks may enhance the perfusion of artificial tissues in vitro, and thereby overcome 1 of the primary obstacles in tissue engineering.