We have developed a novel method to deliver stem cells using 3D bioprinted cardiac patches, free of biomaterials. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), fibroblasts (FB) and endothelial cells (EC) were aggregated to create mixed cell spheroids. Cardiac patches were created from spheroids (CM:FB:EC = 70:15:15, 70:0:30, 45:40:15) using a 3D bioprinter. Cardiac patches were analyzed with light and video microscopy, immunohistochemistry, immunofluorescence, cell viability assays and optical electrical mapping. Cardiac tissue patches of all cell ratios beat spontaneously after 3D bioprinting. Patches exhibited ventricular-like action potential waveforms and uniform electrical conduction throughout the patch. Conduction velocities were higher and action potential durations were significantly longer in patches containing a lower percentage of FBs. Immunohistochemistry revealed staining for CM, FB and EC markers, with rudimentary CD31+ blood vessel formation. Immunofluorescence revealed the presence of Cx43, the main cardiac gap junction protein, localized to cell-cell borders. In vivo implantation suggests vascularization of 3D bioprinted cardiac patches with engraftment into native rat myocardium. This constitutes a significant step towards a new generation of stem cell-based treatment for heart failure.

中文翻译：

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使用人类诱导的多能干细胞衍生的心肌细胞进行无生物材料的三维三维生物打印的心脏组织。

我们已经开发出了一种新颖的方法，该方法可以使用不含生物材料的3D生物打印的心脏贴片来递送干细胞。人类诱导的多能干细胞衍生的心肌细胞（hiPSC-CMs），成纤维细胞（FB）和内皮细胞（EC）聚集在一起，形成混合的细胞球体。使用3D生物打印机从球体（CM：FB：EC = 70：15：15、70：0：30、45：40：15）创建心脏补丁。用光学和视频显微镜，免疫组织化学，免疫荧光，细胞生存力测定和光电映射分析心脏贴片。3D生物打印后，所有细胞比率的心脏组织斑块都自发搏动。斑块表现出类似心室的动作电位波形，并且在整个斑块中具有均匀的导电性。在包含较低百分比的FB的贴片中，传导速度更高，动作电位的持续时间明显更长。免疫组化显示CM，FB和EC标记物染色，并形成了基本的CD31 +血管。免疫荧光显示存在于心脏间隙连接蛋白Cx43的局部细胞-细胞边界。体内植入提示将3D生物打印的心脏补丁植入到天然大鼠心肌中进行血管化。这是朝着新一代基于干细胞的心力衰竭治疗迈出的重要一步。定位到单元格边界。体内植入提示将3D生物打印的心脏补丁植入到天然大鼠心肌中进行血管化。这是朝着新一代基于干细胞的心力衰竭治疗迈出的重要一步。定位到单元格边界。体内植入提示将3D生物打印的心脏补丁植入到天然大鼠心肌中进行血管化。这是朝着新一代基于干细胞的心力衰竭治疗迈出的重要一步。