Mechanobiology of Engineered Heart Tissue

这个项目的总体目标是检查机械提示是否可以改善工程化心脏组织(EHT)结构的收缩功能。EHT构建是通过使用人类细胞来源的心肌细胞的组织工程方法制成的。这些结构可以作为心脏病学和药理学研究的伦理试验台，在某些情况下可以减少对动物研究的依赖。EHT结构是一种功能性组织，因为它们能在体外产生可见的肌肉收缩。然而，在目前最先进的EHT结构中，它们的收缩能力和生理学并不完全类似于成人心脏组织。因此，该项目将使EHT构建物在一种新型生物反应器中动态变化外部负载，以便通过心脏锻炼建立更强大的肌肉组织。如果成功，这个项目将实现一个“心中有数”的平台，用于评估心脏病的新药物治疗方法，了解可遗传的肌病，或研究心脏病理的进展。该项目将为本科生和代表性不足的少数群体提供研究机会。我们将在华盛顿大学的外展活动中向K-12年级的学生宣传我们的研究，教育他们在工程学和医学的交叉点上可能发生的创新。这个项目将提供一种变革性的心脏组织工程方法，通过磁性测量EHT结构的生物力学性能，并提供机械生物学线索，推动它们向成人水平成熟。通过在磁性硅胶桩上生长支架，部分偏向于支架的作用力，可以实时测量EHT支架的收缩力和抽动频率。磁柱的运动将使用多孔板下的新型磁力计阵列来测量，这使得EHT结构能够在很长一段时间内以并行的方式被连续监测。施加在磁柱上的磁场将对EHT结构施加外力，以在收缩(预加载)之前强制拉伸结构，并在收缩(后加载)期间强制约束结构。应用磁力前负荷和后负荷的胎儿负荷模式，将通过复制人类心脏在胎儿发育过程中经历的增加负荷的机械生物学线索，改善EHT结构中hPSC-CM的肌原纤维结构、成熟标志物和收缩输出。更广泛地说，本项目中的方法旨在模拟发育中的人心脏前负荷和后负荷的发育负荷模式，以促进在EHT结构中生长的hPSC-CM的成熟，并通过监测细胞的收缩功能来评估改善情况。

The overall goal of this project is to examine whether mechanical cues can improve the contractile function of engineered heart tissue (EHT) constructs. EHT constructs are made by tissue engineering approaches that use human cell derived cardiomyocytes. These constructs can serve as an ethical testbed for cardiology and pharmacology studies and can reduce the reliance on animal studies in some cases. EHT constructs are functional tissues for they produce muscle contractions that are visible in vitro. However, in the current state-of-the-art for EHT constructs, their contractility and physiology does not fully resemble that of adult heart tissue. As such, this project will subject EHT constructs to dynamically changing external loads in a novel bioreactor in order to build stronger muscle tissue through cardiac exercise. If successful, this project would achieve a "hearts-in-a-dish" platform for assessing new pharmacological treatments for heart disease, understanding inheritable myopathies, or studying the progression of cardiac pathologies. Research opportunities with this project will be provided to undergraduates and underrepresented minority groups. We will publicize our research to K-12 students at outreach events at the University of Washington to educate them on the innovations that are possible at the intersection of engineering and medicine.This project will provide a transformative approach to cardiac tissue engineering by magnetically measuring the biomechanical performance of EHT constructs and providing mechanobiological cues that drive their maturation towards adult levels. Real-time measurements of the contractile force and twitch frequency of EHT constructs will be achieved by growing the constructs on magnetic silicone posts, which deflect in portion to the applied force of the constructs. The motion of the magnetic posts will be measured using a novel array of magnetometers underneath a multi-well plate, which enable the EHT constructs to be monitored continually over a long period of time and in a parallel manner. Application of magnetic fields that pull on the magnetic posts will impart external forces on the EHT constructs to forcibly stretch the constructs before their contraction (preload) and forcibly restrain the constructs during a contraction (afterload). Application of fetal loading patterns of preload and afterload using magnetic forces will improve the myofibril structure, maturation markers, and contractile output of hPSC-CM in the EHT constructs through mechanobiological cues that replicate the increasing loads that the human heart experiences during fetal development. In broader terms, the approaches in this project are intended to mimic to the developmental loading patterns of preload and afterload in a developing human heart in order to improve the maturation of hPSC-CM grown in EHT constructs and assess the improvements by monitoring the contractile function of the cells.