Bioengineered Substrata to Probe Cellular Behavior

动脉内膜增生和血管收缩导致的再狭窄仍然是动脉治疗中的主要问题。 闭塞性疾病。平滑肌细胞在血管重塑和局部调控血管重塑中发挥重要作用。 细胞表型将大大增强减少再狭窄发生的努力。一个常见的结果是 血管损伤是细胞外基质的过度重塑，它富含胶原蛋白和 蛋白多糖。虽然这会导致生化特性的变化，但它也会显著改变 生物力学特性。基于细胞对具有不同机械性能的底物的最新研究 性质，我们的中心假设是基质的生物力学性质将调节 与再狭窄相关的血管平滑肌细胞表型。当前治疗再狭窄的方法 很大程度上涉及可溶性因子，但很少有人关注了解基质的影响。 细胞表型的生物力学特性。拟议研究的目标是创建模型 这些系统将概括血管重塑过程中的生物力学环境，并确定关键 基质顺应性和与再狭窄相关的细胞表型之间的关系。这一目标 将通过研究底物顺应性对Smooth细胞表型的影响来实现 肌肉细胞在模型生物工程底物上，设计为在其 顺应性从微观到宏观的长度范围。这项研究的结果将是 一种新的体外模型系统，将更接近于重塑的生物力学环境 可以在其中测试药物对血管平滑肌细胞表型的影响的基质。这款车 该系统也可应用于其他病理生理系统。 为了控制局部的机械柔度，将使用合成水凝胶作为模型底物。目标 1是在宏观和微观层面上开发具有明确机械顺应性的生物工程基质。 比例。目标2和目标3的研究结果将用于目标1的改进。目标2将建立和 量化基质顺应性与相关血管平滑肌细胞表型之间的关系 伴有再狭窄。目标3将测试底物顺应性对表达、定位和 可能的机械传感细胞组件(整合素、细胞骨架、FAK、巴西林、Rho)的活性 GTP酶)。这些研究将对控制表型调控的物理因素提出新的见解 研究血管平滑肌细胞，目的是开发阻断再狭窄的治疗方法。

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.