In vitro cultures to be used in various analytical investigations of cardiomyocyte (CM) growth and function for enhancing insight into physiological and pathological mechanisms should closely express in vivo morphology. The aim of the studies is to explore how to use microfabrication and physical-cue-addition techniques to establish a neonatal rat CM culture model that expresses an end-to-end connected rod shape with in vivo-like intercalated discs (ICDs). Freshly isolated neonatal rat CMs were cultured on microgrooved polydimethylsiloxane substrate. Cell alignment and ICD orientation were evaluated using confocal fluorescence and transmission electron microscopy under various combinations of different culture conditions. Cyclic stretch and blebbistatin tests were conducted to explore mechanical and electrical effects. Laboratory-made MATLAB software was developed to quantify cell alignment and ICD orientation. Our results demonstrate that the mechanical effect associated with the electrical stimulation may contribute to step-like ICD formation viewed from the top. In addition, our study reveals that a suspended elastic substrate that was slack with scattered folds, not taut, enabled CM contraction of equal strength on both apical and basal cell surfaces, allowing the cultured CMs to express a three-dimensional rod shape with disc-like ICDs viewed cross-sectionally.

中文翻译：

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在新生儿心肌细胞培养模型中实现了闰盘的体内样形态。

用于心肌细胞（CM）生长和功能的各种分析研究以增强对生理和病理机制的了解的体外培养物应该密切表达体内形态。研究的目的是探索如何使用微加工和物理提示添加技术建立新生大鼠 CM 培养模型，该模型表达具有体内样闰盘（ICD）的端到端连接杆形状。新鲜分离的新生大鼠 CM 在微槽聚二甲基硅氧烷基质上培养。在不同培养条件的各种组合下，使用共焦荧光和透射电子显微镜评估细胞排列和ICD方向。进行循环拉伸和肌球蛋白测试以探索机械和电效应。开发了实验室制作的 MATLAB 软件来量化细胞排列和 ICD 方向。我们的结果表明，与电刺激相关的机械效应可能有助于从顶部观察阶梯状 ICD 的形成。此外，我们的研究表明，悬浮的弹性基质是松弛的，具有分散的褶皱，而不是绷紧的，使得顶端和基底细胞表面上的CM收缩具有相同的强度，使得培养的CM能够表达具有圆盘状的三维棒状形状。就像 ICD 的横截面一样。