3D bioprinting is a widely used technology to dispense cell-laden biomaterials for rapid fabrication of complex 3D tissue constructs or artificial organs. To date, many studies have been investigated the deposition and patterning of cell-laden bioinks with a 3D bioprinter. However, the precise positioning, reasonable mechanical properties, and controlled cell distributions of constructs in 3D bioprinting system still remains technical challenges.
In this study, we developed heterogeneous cell-laden microchannel network using human umbilical vein endothelial cell-cardiomyocytes by a direct patterning with a 3D bioprinter. We fabricated 3D tissue constructs consisting of the core (human umbilical vein endothelial cell -laden collagen) and the sheath (cardiomyocytes-laden gelatin methacrylate). We could achieve a stable 3D multilayered core-sheath structure with the reasonable elastic modulus. This system also facilitated cell alignment and migration within each constructs and promoted vascular network with high cell viability. Calcium imaging was used to optically probe intracellular calcium ion signals during excitation-contraction coupling in cardiomyocytes within 3D vascular network.
This paper presents the new approach for fabricating vascularized heterogeneous 3D scaffolds and highly controlled deposition technique of bioinks. The cell-laden 3D constructs could be extended to serve as in vitro models for clinical cardiovascular disease researches and cardiovascular tissue regenerations.