Modeling the mechanics of tissue-engineered human heart valve leaflets.

Mathematical models can provide valuable information to assess and evaluate the mechanical behavior of tissue-engineered constructs. In this study, a structurally based model is applied to describe and analyze the mechanics of tissue-engineered human heart valve leaflets. The results from two orthogonal uniaxial tensile tests are used to determine the model parameters of the constructs after two, three and four weeks of culturing. Subsequently, finite element analyses are performed to simulate the mechanical response of the engineered leaflets to a pressure load. The stresses in the leaflets induced by the pressure load increase monotonically with culture time due to a decrease in the construct's thickness. The strains, on the other hand, eventually decrease as a result of an increase in the elastic modulus. Compared to native porcine leaflets, the mechanical response of the engineered tissues after four weeks of culturing is more linear, stiffer and less anisotropic.