Strain effects on collagen proteolysis in heart valve tissues

  • Kaitlyn Barbour
  • Hsiao-Ying Shadow HuangEmail author


Collagen is at the heart of any and all questions concerning semilunar valvular leaflet composition, structure, and function. Whether during development, physiological homeostasis, or pathological degeneration, it is the structural-mechanical state of the heart valve leaflet collagen network that ultimately confers valvular function, and the difference between health and disease. In the current study, the effects of physiologically relevant strain states on collagen catabolism are investigated in porcine aortic and pulmonary valve leaflets. Application of bacterial collagenase to the tissues which acts to simulate collagen degradation by endogenous matrix metalloproteinases, biaxial stress relaxation, and histology are all used to serve as measures of functional and compositional collagen catabolism. Current stress-relaxation results are used in conjunction with previous equibiaxial testing to confirm that a mechanism exists to prevent collagen catabolism when stretched at physiologically relevant strain states. Collectively, these in vitro results indicate that biaxial strain states are capable of impacting the susceptibility of valvular collagens to catabolism, and that at physiological strain states, a protective mechanism exists to effectively block collagen catabolism. The results of the study will be broadly applicable to clarify the roles of tissue microarchitecture and load transmission in a variety of other developmental, homeostatic, or pathogenic tissue processes such as tumor growth, embryogenesis, thrombi formation, and atherogenesis.


Physiological strains Biomechanical testing or analysis Tissue biomechanics Stress relaxation 



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© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Mechanical and Aerospace Engineering DepartmentNorth Carolina State UniversityRaleighUSA

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