Valvular Tissue Engineering Using 3D Printing—Hemodynamic and Functional Measurements of Different Matrix Structures

Background: In patients needing a heart valve replacement, different therapeutic options are available. However, all currently available heart valves have their limitations. While biological tissue valves from porcine or bovine pericardium are limited in their durability, mechanical valves on the other hand need a lifelong anticoagulation. In recent years several valvular tissue engineering approaches have been evaluated to overcome those limitations. We here generated different engineered heart valves from polymer-based hydrogels and living cells and compared their biomechanical properties.

Methods: First, a 3D casting mold was constructed with Solidworks CAD Software. Using a 3D-bioprinter the tissue engineered heart valve was constructed within the casting mold. In group A the valves (n = 6) were printed from 100% alginate, while in group B (n = 6) a mixture of 50% alginate, collagen and elastin extracted from decellularized porcine aortic tissue was used. Second, human iPSC-derived endothelial cells are differentiated and the cells are seeded onto the tissue engineered heart valves. Histological analysis, bioluminescence imaging and functional measurements of the tissue engineered valves were performed.

Results: In both groups, tissue engineered valves could be successfully constructed and evaluated in a pulse duplicator. Structure and shape of the valves were comparable between groups. Using bioluminescence imaging, living hiPS-derived endothelial cells could be detected on both valve types, with a significantly higher bioluminescence signal intensity in group B (Group B 4.9x108 ROI versus Group A 4.2x106 ROI p < 0.001). Elasticity was compared between both groups, showing 18% higher elasticity in the alginate/ collagen/elastin group (B). Tissue valve opening area at maximum stroke volume was 53% ± 8% in Group A and 82% ± 11% in group B.

Conclusion: Tissue engineered valves from alginate and alginate/collagen/elastin were successfully generated with shape and structure of a functional heart valve. Alginate/Collagen/Elastin mixture showed higher elasticity and larger valve opening area. Furthermore, bioluminescence imaging showed significantly higher number of living hiPS-derived endothelial cells in this group.

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Artikel online veröffentlicht:
13. Februar 2024