In Vitro Synthesis of a Microvascular Network

描述(由申请人提供)：这份为期两年的建议书描述了在体外合成人类真皮微血管网络的过程中，基于微光刻技术的发展。这项工作中开发的方法将支持以下长期目标：1)体外模拟人类炎症反应，以高通量筛选可以逆转诱导反应的药物；2)设计具有集成血管系统的全厚皮肤移植物。通过允许合成具有受控微尺度结构的组织，这些光刻方法将补充组织工程中依赖于生长因子诱导的细胞自组织的现有策略。所提出的方案将最初将原代微血管细胞安排成一个开放的管的三维网络，然后不断地灌流该结构，使其成熟为功能微循环。我们将确定网络剪应力、管腔压力和氧化压力的范围，使合成的结构能够形成具有人类真皮微血管床特征的组织结构。此外，我们将改变灌流条件，以调节体外网络对炎性细胞因子的反应性，并增强刺激网络中中性粒细胞的外渗。这项工作将进一步确定由两个相互连接的神经丛组成的工程化微血管结构可以维持代谢的组织厚度。

DESCRIPTION (provided by applicant): This two-year proposal describes the development of processes, based on microlithography, to synthesize a human dermal microvascular network in vitro. The methods developed in this work will support the following long-term goals: 1) modeling of human inflammatory responses in vitro for high-throughput screening of agents that can reverse an induced response, and 2) engineering of full-thickness skin grafts with an integrated vasculature. By allowing the synthesis of tissue with a controlled microscale architecture, these lithographic methods will complement current strategies in tissue engineering that rely on cellular self-organization induced by growth factors. The proposed schemes will arrange primary microvascular cells into a three-dimensional network of open tubes initially, and then continuously perfuse the construct to allow its maturation into a functional microcirculation. We will determine the ranges of network shear stress, luminal pressure, and oxidative stress that enable the as-synthesized construct to develop a histological organization characteristic of a human dermal microvascular bed. Moreover, we will vary perfusion conditions to tune the reactivity of the in vitro network to inflammatory cytokines, and to enhance the extravasation of neutrophils in a stimulated network. This work will further determine the thickness of tissue that can be sustained metabolically by an engineered microvascular construct comprised of two interconnected plexuses.