We present a wafer-scale fabricated, PDMS-based platform for culturing miniaturized engineered heart tissues (EHTs) which allows highly accurate measurements of the contractile properties of these tissues. The design of the platform is an anisometrically downscaled version of the Heart-Dyno system, consisting of two elastic micropillars inside an elliptic microwell with volume ranging from 3 down to $1\mu \text{L}$ which supports EHT formation. Size downscaling facilitates fabrication of the platform and makes it compatible with accurate and highly reproducible batch wafer-scale processing; furthermore, downscaling reduces the cost of cell cultures and increases assay throughput. After fabrication, the devices were characterized by nanoindentation to assess the mechanical properties of the pillars and transferred to 96-well plates for cell seeding. Regardless the size of the platform, cell seeding resulted in successful formation of EHTs and all tissues were functionally active (i.e. showed cyclic contractions). The precise characterization of the stiffness of the micropillars enabled accurate measurements of the contractile forces exerted by the cardiac tissues through optical tracking of micropillar displacement. The miniature EHT platforms described in this paper represent a proper microenvironment for culturing and studying EHTs. [2020-0130]

中文翻译：

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用于精确测量组织收缩特性的小型化 EHT 平台

我们提出了一个晶圆级制造的、基于 PDMS 的平台，用于培养微型工程心脏组织 (EHT)，可以高度准确地测量这些组织的收缩特性。该平台的设计是 Heart-Dyno 系统的等距缩小版本，由椭圆形微孔内的两个弹性微柱组成，体积范围从 3 到 $1\mu\text{L}$，支持 EHT 形成。尺寸缩小有利于平台的制造，并使其与准确且高度可重复的批量晶圆级加工兼容；此外，缩小规模可降低细胞培养的成本并提高检测通量。制造后，通过纳米压痕对器件进行表征，以评估支柱的机械性能，并转移到 96 孔板进行细胞接种。无论平台的大小如何，细胞接种都会导致 EHT 的成功形成，并且所有组织都具有功能活性（即显示循环收缩）。微柱刚度的精确表征能够通过微柱位移的光学跟踪准确测量心脏组织施加的收缩力。本文中描述的微型 EHT 平台代表了用于培养和研究 EHT 的适当微环境。[2020-0130] 微柱刚度的精确表征能够通过微柱位移的光学跟踪准确测量心脏组织施加的收缩力。本文中描述的微型 EHT 平台代表了用于培养和研究 EHT 的适当微环境。[2020-0130] 微柱刚度的精确表征能够通过微柱位移的光学跟踪准确测量心脏组织施加的收缩力。本文中描述的微型 EHT 平台代表了用于培养和研究 EHT 的适当微环境。[2020-0130]