Protocol for extrusion 3D bioprinting of human-scale cardiac patches using cardiac spheroid-laden bioinks

Extrusion-based bioprinting is a promising approach for developing novel clinical therapies for heart failure patients. Here, we present a protocol for bioprinting personalized human-scale cardiac patches incorporating human cardiac spheroids in a 1% silk fibroin/4% alginate/8% gelatin hydrogel. We describe steps for extrusion 3D bioprinting using a temperature-controlled hydrogel bioink. We also detail adjusting print parameters for optimal results. Although prepared for a specific experimental setup, the techniques described can be applied to other temperature-controlled biomaterials or extrusion 3D bioprinters. For complete details on the use and execution of this protocol, please refer to Roche et al.,^1,2 Sharma et al.,³ and Vettori et al.⁴.