Application of Simple Biomechanical and Biochemical Tests to Heart Valve Leaflets: Implications for Heart Valve Characterization and Tissue Engineering

This study combined biaxial mechanical testing with biochemical analysis to characterize the structure–function relationships of porcine aortic and pulmonary heart valve leaflets. Using equibiaxial stretching up to 35% strain, the authors quantified nonlinear, anisotropic mechanical behavior and identified distinct strain-dependent stiffness regimes governed by collagen fiber realignment. Real-time strain and principal direction maps revealed valve-specific differences in fiber recruitment, with pulmonary valves exhibiting greater anisotropy at high strains. Complementary biochemical assays demonstrated that collagen concentration depends strongly on extraction time and leaflet location, providing essential benchmarks for native tissue properties relevant to heart valve tissue engineering.