3D-Bioprinting of hiPSC-Derived Heart Valves Using Alginate/Collagen Bioink: Structural Integrity, Cell Viability, and Functional Performance

All articles of this category (opens in new window) Background: Bioprinting enables the generation of patient-specific living tissues with high structural precision. In cardiovascular medicine, this approach holds promise for addressing major unmet needs in heart failure and valvular disease, where current prosthetic solutions lack biological integration and regenerative capacity. The use of hiPSC-derived cardiomyocytes combined with bioinks such as alginate and collagen may allow fabrication of functional myocardial and valvular constructs with potential for clinical translation in cardiac repair. Methods: A conventional 3D printer was modified into an extrusion-based bioprinter with cold-extrusion capability. Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes were embedded in an alginate/collagen (2:1) bioink and bioprinted as infinity-shaped constructs into a FRESH gelatin support bath. Printing parameters were systematically optimized to ensure construct fidelity and cell viability. Cell distribution and survival were evaluated by histological analysis and bioluminescence imaging. Heart valves were printed using either pure alginate (Group A, n = 4) or alginate/collagen (2:1; Group B, n = 4) and subsequently analyzed for mechanical stability, function, and hemodynamics in a pulse duplicator system. All constructs were crosslinked after printing and assessed for integrity and viability. Results: Optimization of printing parameters enabled reproducible fabrication of stable, structurally accurate constructs. Bioluminescence imaging demonstrated robust cell viability immediately after printing and a significant increase after 48 hours ( p < 0.001). Material performance testing revealed a 15% higher effective orifice area in Group B (0.76 ± 0.07 cm 2 ) compared with Group A (0.66 ± 0.03 cm 2 , p < 0.05). The mean transvalvular pressure gradient was 30.71 ± 4.98 mmHg in Group A vs. 20.36 ± 7.98 mmHg in Group B ( p < 0.05), indicating greater stiffness in alginate-only valves. Conclusion: Bioprinted constructs were manufactured with high shape fidelity and structural integrity. The alginate/collagen bioink supported superior cell viability, as demonstrated by bioluminescence imaging, and provided greater elasticity compared with pure alginate, while maintaining comparable material strength. These findings support the feasibility of bioprinting for the fabrication of viable tissue-engineered heart valves with potential applications in regenerative cardiac repair. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany