Bioprinting A Physiologically Aligned, Thick Cardiac Tissue for Regenerative Medicine

项目摘要 每年有75万美国人经历心脏病发作，其中许多人发展为心力衰竭。心脏衰竭， 占美国每年死亡人数的10%，其特点是抽水不足 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 不能解决细胞丢失的根本问题。干细胞衍生的心肌细胞代表了 无限的，个性化的治疗，具有再生这种收缩功能的潜力。 近年来，干细胞衍生的心肌细胞移植恢复了恒河猴的心脏功能 通过手术诱发心脏病发作的猴子。这种高度平移模型的显著改进是 这至少部分归因于移植细胞产生的收缩力。尽管有了这些改善 在功能方面，4周后仅约5%的细胞存活。组织工程代表了一种方法， 通过复制的细胞和细胞外基质组成的肌肉重建策略， 心 在心脏中，细胞以双螺旋三维结构定向。这种取向产生了 像拧一块湿抹布一样扭动。这种扭曲有助于将心肌细胞15%的缩短和8%的增厚扩展到 射血分数65%朝向产生能够适应于患者的大小和位置的个性化治疗 我们的目标是概括心肌的结构和扭转功能。的 这一建议的中心假设是：1）复制心肌的生理扭曲是必要的， 心脏重新肌肉化，以及2）3D生物打印对齐的心脏片， 方向将产生扭曲。重要的是，这种方法是对以前开发的3D打印技术的补充。 血管化策略，并实现可扩展和可定制的方法。总的来说，该项目旨在产生 一个更生理的组织，可用于研究收缩功能的生理指标，这将 为旨在使心脏肌肉化的体内研究提供信息。此外，此类组织可能有助于阐明疾病 以前无法用更简单的体外模型识别的机制。 目的1：生成由对齐的各向异性心脏μ组织组成的可打印生物墨水。 目标2：将载有μ组织的墨水3D生物打印到单轴对齐的心脏组织片中。 目标3：确定3D生物打印层之间的相对对齐如何影响扭曲参数。

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.