From Fiber Architecture to Functional Attachment: A Clinically Relevant, Mechanically Tunable Cardiac Patch.

Contractile engineered cardiac patches hold great potential for treating myocardial infarction, serving as biological ventricular assist devices (BioVADs). However, optimal design and attachment of cardiac patches remain insufficiently explored, although both are essential for the mechanical support of damaged hearts. This study presents a platform for personalized macroscale patches with a multi-zonal microarchitecture combining a regenerative zone for cell alignment, a stiff force transmission zone for load transfer, and an elastic attachment zone enabling integration. Based on computational modeling, the design is implemented using a custom G-code generator for melt electrowriting (MEW). Digital image correlation reveals up to a 2.6-fold strain difference between scaffold zones under physiological deformation, confirming zonal interplay. Biaxial testing with preconditioning shows scaffold mechanics replicating native myocardium properties up to 10% strain. For epicardial suture attachment, a reinforced outline enables shape-morphing and increases suture retention 2.16-fold. Dynamic BioVAD cultivation with fibrin-embedded cardiomyocytes significantly (p = 0.01) improves cell alignment versus controls. Finally, in a porcine myocardial infarction model, the BioVAD achieves complete epicardial attachment and vascular ingrowth within 7 days, compared to partial attachment in controls. This study highlights MEW as a versatile platform for tailoring cardiac scaffold mechanics to support tissue integration and cardiac function.