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A Novel Stretching Platform for Applications in Cell and Tissue Mechanobiology
Published on: June 3, 2014
Structural strain energy function applied to the ageing of the human aorta
Martin A Zulliger1, Nikos Stergiopulos
1Laboratory of Hemodynamics and Cardiovascular Technology, Institute for Bioengineering and Biotechnology, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne, Switzerland. martin.zulliger@epfl.ch
Journal of Biomechanics
|September 8, 2007
Summary
Aging stiffens the aorta by altering collagen fiber arrangement, not elastin or collagen content. This abrupt collagen engagement significantly reduces aortic compliance in older individuals.
Area of Science:
- Biomedical Engineering
- Cardiovascular Physiology
- Materials Science
Background:
- Aortic stiffening with age decreases compliance and increases pulse pressure.
- Understanding age-related biomechanical changes in the aorta is crucial for cardiovascular health.
Purpose of the Study:
- To investigate the age-related evolution of structural components in the human thoracic aorta.
- To identify the primary biomechanical factors contributing to decreased aortic compliance in aging.
Main Methods:
- Utilized a strain energy function (SEF) incorporating collagen waviness and fiber engagement.
- Analyzed literature data on human thoracic aorta properties, including axial stretch and opening angle.
- Applied SEF to aortic pressure-diameter curves to model biomechanical behavior.
Main Results:
- Age-related aortic biomechanical changes are primarily due to alterations in collagen mesh arrangement and fiber waviness.
- Collagen fiber engagement becomes significantly more abrupt in older subjects.
- The abruptness of collagen engagement is the key factor driving decreased aortic compliance with age.
Conclusions:
- Reduced aortic compliance in aging is linked to changes in collagen fiber dynamics, not elastin/collagen content or volume fractions.
- Collagen fiber waviness remodeling or cross-linking by advanced glycation end-products (AGEs) may explain altered collagen dynamics.
- The SEF provides a framework for understanding age-dependent biomechanical alterations in the aorta.
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