Aortic Valve: Mechanical Environment and Mechanobiology

• Type of Material: Article
• Authors: Sivakkumar Arjunon, Georgia Institute of Technology; Swetha Rathan, Georgia Institute of Technology; Hanjoong Jo, Emory University; Ajit Yoganathan, Emory University
• Language: English
• Date: 2013-07-01
• Publisher: Springer Verlag (Germany)
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: Copyright © 2013, Biomedical Engineering Society
• Final Published Version (URL): http://dx.doi.org/10.1007/s10439-013-0785-7
• Title of Journal or Parent Work: Annals of Biomedical Engineering
• ISSN: 0090-6964
• Volume: 41
• Issue: 7
• Start Page: 1331
• End Page: 1346
• Grant/Funding Information: Authors also would like to thank all the relevant funding sources for the Cardiovascular Fluid Mechanics lab at Georgia Tech: American Heart Association under the Post-doctoral Research Awards (0625620B, 10POST3050054) and Predoctoral Research Award (09PRE2060605), National Science Foundation through the Engineering Research Center program at the Georgia Tech under the award EEC 9731643, National Heart, Lung and Blood Institute grant number HL-07262, the Wallace H. Coulter Distinguished Faculty Chair funds, Petit Undergraduate Research Scholars Program, a gift from Tom and Shirley Gurley, and all other sources.
• Keywords: Bicuspid; Stretch; TRANSFORMING GROWTH-FACTOR-BETA-1; ENGINEERED HEART-VALVES; Shear stress; CYCLIC STRETCH; Engineering, Biomedical; Aortic valve; EX-VIVO; Mechanobiology; VALVULAR ENDOTHELIAL-CELLS; Science & Technology; BIOLOGICAL-PROPERTIES; Engineering; Pressure; ORGAN-CULTURE; INTERSTITIAL-CELLS; FLUID SHEAR-STRESS; SMOOTH-MUSCLE-CELLS; Calcification; Technology; ENGINEERING, BIOMEDICAL
• Research Categories: Engineering, Biomedical; Health Sciences, Medicine and Surgery

Abstract

The aortic valve (AV) experiences a complex mechanical environment, which includes tension, flexure, pressure, and shear stress forces due to blood flow during each cardiac cycle. This mechanical environment regulates AV tissue structure by constantly renewing and remodeling the phenotype. In vitro, ex vivo and in vivo studies have shown that pathological states such as hypertension and congenital defect like bicuspid AV (BAV) can potentially alter the AV's mechanical environment, triggering a cascade of remodeling, inflammation, and calcification activities in AV tissue. Alteration in mechanical environment is first sensed by the endothelium, which in turn induces changes in the extracellular matrix, and triggers cell differentiation and activation. However, the molecular mechanism of this process is not understood very well. Understanding these mechanisms is critical for advancing the development of effective medical based therapies. Recently, there have been some interesting studies on characterizing the hemodynamics associated with AV, especially in pathologies like BAV, using different experimental and numerical methods. Here, we review the current knowledge of the local AV mechanical environment and its effect on valve biology, focusing on in vitro and ex vivo approaches. © 2013 Biomedical Engineering Society.