Bioprinting A Physiologically Aligned, Thick Cardiac Tissue for Regenerative Medicine

项目总结 每年有75万美国人心脏病发作，其中许多人发展为心力衰竭。心力衰竭, 占美国每年死亡人数的10%，其特点是抽水不足 这限制了外周器官的血液供应。目前的治疗方法无法缓解这种下降，因为它们 不解决细胞丢失的根本问题。干细胞来源的心肌细胞是一种 无限制的个性化治疗，具有再生这种收缩功能的潜力。 最近，干细胞来源的心肌细胞移植恢复了恒河猴的心功能。 患有外科手术引发的心脏病的猴子。这种高度平移的模型的显著改进是 至少部分归因于移植细胞产生的收缩力量。尽管有了这样的改进 在功能方面，仅有5%的细胞在4周后存活。组织工程代表了一种方法 通过复制细胞和细胞外基质成分来改进肌化策略 心。 在心脏中，细胞以双螺旋三维结构定向。此方向会生成 扭动就像拧湿了的抹布。这一扭转有助于将心肌细胞15%的缩短和8%的增厚扩大到 65%的射血分数。产生一种能够适应体型和体位的个性化治疗 对于个人的心脏病发作，我们的目标是概括心肌的结构和扭转功能。这个 这一建议的中心假设是：1)复制心肌的生理扭曲是必要的 心脏肌肉化，以及2)3D生物打印对齐的心瓣膜，具有生理上的相对变化 方向会产生扭曲。重要的是，这种方法是对以前开发的3D打印的补充 血管化策略，并实现了可扩展和可定制的方法。总体而言，该项目旨在产生 一种更具生理性的组织，可用于研究收缩功能的生理指标，这将 为旨在使心脏重新肌化的体内研究提供信息。此外，这样的组织可能有助于阐明疾病 以前用更简单的体外模型无法识别的机制。 目的1：生成由排列的、各向异性的心脏μ组织组成的可打印的生物墨水。 目的2：将μ组织墨水3D生物打印到单轴排列的心脏组织片上。 目的3：确定3D生物打印层之间的相对排列如何影响扭曲参数。

PROJECT SUMMARY Each year 750,000 American experience a heart attack, many of whom progress to heart failure. Heart failure, which accounts for 10% of annual deaths in the United States, is characterized by insufficient pumping that restricts the blood supply to peripheral organs. Current treatments cannot mitigate this decline as they do not address the fundamental problem of cell loss. Stem cell derived cardiomyocytes represent an unlimited, personalized therapy with demonstrated potential to regenerate this contractile function. Recently, the transplantation of stem cell derived cardiomyocytes restored heart function in rhesus monkeys with surgically induced heart attacks. The dramatic improvement in this highly translational model is attributed at least in part to the contractile force generated by the transplanted cells. Despite this improvement in function, only ~5% of cells survived after 4 weeks. Tissue engineering represents one approach to improve the re-muscularization strategy by replicating the cellular and extracellular matrix composition of the heart. In the heart, cells are oriented in a double helical, three-dimensional architecture. This orientation generates twist akin to wringing a wet rag. This twist helps scale a cardiomyocyte’s 15% shortening and 8% thickening to a 65% ejection fraction. Towards generating a personalized therapy capable of adapting to the size and position of an individual’s heart attack, we aim to recapitulate the architecture and torsional function of myocardium. The central hypothesis of this proposal are: 1) replicating the physiological twist of myocardium is necessary for cardiac re-muscularization, and 2) 3D bioprinting aligned cardiac sheets with physiologically relative changes in orientation will generate twist. Importantly, this approach is complementary to previously developed, 3D printed vascularization strategies and enables a scalable and tailorable approach. Overall, this project aims to generate a more physiological tissue that can be used to study physiological indicators of contractile function, which will inform in vivo studies that aim to re-muscularize the heart. In addition, such tissue may help elucidate disease mechanisms previously unidentifiable with simpler in vitro models. Aim 1: Generate a printable bioink composed of aligned, anisotropic cardiac μtissues. Aim 2: 3D bioprint μtissue-laden inks into uniaxially aligned cardiac tissue sheets. Aim 3: Determine how relative alignment between 3D bioprinted layers impacts parameters of twist.