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.