Structure-Function Relationship of Heart Valves in Health and Disease

Abstract

The heart valves allow unidirectional and unobstructed passage of blood without regurgitation, trauma to blood elements, thromboembolism, and excessive stress concentrations in the leaflet and supporting tissue. In order to achieve this, the heart valves rely of their unique macroscale anatomy, histoarchitecture and ultrastructural features that allow them to accommodate repetitive changes in shape and dimension throughout the cardiac cycle. This chapter is focused on the structure-function relationship of the heart valves, with particular focus on the aortic and mitral valves, discussing how the biochemical, histoarchitectural and anatomical features influence valvular function during the cardiac cycle and how valvular function dictates valvular architecture and ECM constitution. The chapter examines the structure-function relationship of valvular tissue by correlating its microscale histoarchitecture and biochemical constitution to its mesoscale biomechanics and macroscale function during the cardiac cycle. Moreover, the chapter examines the influence of pathological alterations on the histoarchitectural and biochemical characteristics of the valves on their biomechanical behavior.

Soft Materials by Design: Unconventional Polymer Networks Give Extreme Properties

“…Design principles and implementation strategies for various biological hydrogels to achieve extreme mechanical properties: (a) high toughness of cartilage due to viscoelastic and poroelastic dissipation of the polymer networks, ,, (b) high tensile strength of tendon due to simultaneous stiffening of multiple polymers in the fibrous hierarchical structure, , (c) high resilience and facture toughness of heart valve due to delayed mechanical dissipation, , (d) high interfacial fatigue threshold of cartilage–/ligament–/tendon–bone interfaces due to intrinsically high-energy phases including nanocrystals and nanofibers strongly bonded on the interfaces . Panel (a) is reproduced with permission from ref .…”

“…Copyright 2013 Elsevier. Panel (c) is reproduced with permission from refs and . Copyright 2014 PLoS and 2018 IntechOpen.…”

Bioprinted hASC‐laden collagen/HA constructs with meringue‐like macro/micropores

“…16,17,[24][25][26] In this study, collagen was used to fabricate the meringue-like foam structure because the collagen fibrous protein molecules are composed of hydrophobic (glycine and proline) and hydrophilic amino acid (hydroxyproline) [Figure 1b]. 35,36 Hence, the protein molecules of collagen are expected to be entrapped between the air bubbles and aqueous solution, forming an interfacial fibrous wall through the whipping process [Figure 1c-e], similar to the mechanism of egg white protein formation in the culinary field. 15 To achieve a meringue-like structure, the whipper shown in Figure 1f was rotated using an automatic stirrer to control the rotating speed such that the whipping process can be analyzed quantitatively.…”

Interdisciplinary Methods for Zoonotic Tissue Acellularization for Natural Heart Valve Substitute of Biomimetic Materials

“…A Poisson’s number of 0.475 was assumed for each layer. Table 1 summarizes the elastic and hyperelastic parameters for the tissue materials [ 56 , 57 ] used in the simulations. As the table shows, the Ogden material model was used to model the hyperelasticity, in which the relationship between stress and strain results from the strain energy function W .…”

“…In the first approach [ 55 ], simulations were performed on single-layer samples with the use of rheological models identified by the authors. In the present paper, simulations were performed on three-layer samples with preservation of the histological structure of the tissue of animal origin using hyperelastic material models [ 56 , 57 ].…”