Bioengineered Substrata to Probe Cellular Behavior

由于内膜增生和血管收缩引起的呼吸仍然是动脉粥样硬化治疗中的主要问题。 闭塞性疾病平滑肌细胞在血管重塑中起主要作用，并且局部控制其功能。 细胞表型将大大增强减少再狭窄发生的努力。一个共同的结果是， 血管损伤是细胞外基质的过度重塑，其变得富含胶原蛋白， 蛋白聚糖虽然这会导致生化特性的变化，但它也会显著改变 生物力学性能基于最近的研究，细胞对基质的反应具有不同的机械性质， 我们的中心假设是，底层的生物力学特性将调节 与再狭窄相关的血管平滑肌细胞细胞表型。再狭窄的当前治疗方法 大部分涉及可溶性因素，但很少注意了解基质的影响 细胞表型的生物力学特性。本研究的目的是建立一个模型 这些系统将概括血管重塑期间的生物力学环境，并确定关键的 基质顺应性与再狭窄相关的细胞表型之间的关系。这一目标 将通过研究基质顺应性对光滑细胞表型的影响来实现 在模型生物工程基质上的肌肉细胞被设计成在其细胞的分化中表现出系统性变化， 从微观到宏观的长度尺度范围内的顺应性。这项研究的结果将是 一种新的体外模型系统，将更接近地模拟重塑的生物力学环境， 基质，其中可以测试试剂对血管平滑肌细胞表型的影响。该模型 该系统也可以应用于其他病理生理系统。 合成水凝胶将用作模型基质，以控制局部机械顺应性。目的 1是开发生物工程基质，在宏观和微观上具有明确的机械顺应性， 鳞片目标2和3的研究结果将用于目标1的完善。目标2将建立和 量化基质顺应性和血管平滑肌细胞表型之间的关系 再狭窄目的3将测试底物顺应性对表达、定位和表达的影响。 推定的机械感测细胞组分（整合素、细胞骨架、FAK、桩蛋白、Rho）的活性 GTP酶）。这些研究将推进对控制表型调节的物理因素的新见解 血管平滑肌细胞，目的是开发治疗方法，以阻止再狭窄。

Restenosis due to intimal hyperplasia and vasoconstriction remains a major problem in treatments of arterial occlusive disease. Smooth muscle cells play a major role in vascular remodeling, and local control of their cellular phenotype would greatly enhance efforts to reduce the occurrence of restenosis. A common result of vascular injury is excessive remodeling of the extracellular matrix, which becomes rich in collagens and proteoglycans. While this leads to changes in biochemical properties, it also significantly alters biomechanical properties. Based on recent work that cells respond to substrata with varying mechanical properties, our central hypothesis is that the biomechanical properties of the substratum will modulate vascular smooth muscle cell cellular phenotype that is relevant for restenosis. Current therapies for restenosis largely involve soluble factors, but little attention has been focused on understanding the effects of substratum biomechanical properties on cellular phenotype. The objective of the proposed research is to create model systems that will recapitulate the biomechanical environment during vascular remodeling and to identify key relationships between substrate compliance and cellular phenotype associated with restenosis. This objective will be achieved by investigating the effect of substrate compliance on the cellular phenotype of smooth muscle cells on model bioengineered substrata that are designed to exhibit a systematic variation in their compliance ranging from the microscopic to macroscopic length scales. The outcome of this research will be a novel in vitro model system that will more closely mimic the biomechanical environment of the remodeled matrix in which one can test the effects of agents on vascular smooth muscle cell phenotype. This model system can also be applied to other pathophysiologic systems. Synthetic hydrogels will be used as model substrata in order to control the local mechanical compliance. Aim 1 is to develop bioengineered substrata with well-defined mechanical compliance at the macro- and micro- scales. Results from studies in Aims 2 and 3 will be used in the refinement of Aim 1. Aim 2 will establish and quantify relationships between substrate compliance and vascular smooth muscle cell phenotypes associated with restenosis. Aim 3 will test the effects of substrate compliance on the expression, localization, and activity of putative mechanosensing cellular components (integrins, cytoskeleton, FAK, paxillin, Rho GTPases). These studies will advance new insights on the physical factors that control phenotypic modulation of vascular smooth muscle cells with the aim of developing therapies to block restenosis.