LAUSR

The ability to replicate the three-dimensional myocardial architecture found in human hearts is a grand challenge. Here, we report the fabrication of aligned cardiac tissues via bioprinting anisotropic organ building blocks (aOBBs) composed of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). We first generated a bioink composed of contractile cardiac aOBBs and printed aligned cardiac tissue sheets with linear, spiral, and chevron features. Next, we printed aligned cardiac macrofilaments, whose contractile force and conduction velocity increased over time and exceeded the performance of spheroid-based cardiac tissues. Finally, we highlighted the ability to spatially control the magnitude and direction of contractile force by printing cardiac sheets with different aOBB alignment. Our research opens new avenues to generating functional cardiac tissue with high cell density and complex cellularly alignment. This article is protected by copyright. All rights reserved.