"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." Atherosclerotic plaque rupture is the leading cause of acute cardiovascular events such as heart attack and stroke. Many studies of atherosclerosis use mice as an animal model, since plaque structure and composition can easily be altered using genetic engineering, drugs, or diet. However, spontaneous plaque rupture is rare in atherosclerotic mice, necessitating new approaches to relate the pathology of mouse plaques to their biomechanical properties and stability against rupture. This project will apply two novel approaches to study the biomechanical behavior of mouse atherosclerotic plaques: 1. measurement of local surface strains on normal arteries and plaques under tensile loading using three-dimensional digital image correlation (3D-DIC), a non-contacting optical method; 2. direct measurement of the forces necessary to cause detachment of the plaque from the underlying vessel wall, in order to estimate plaque-artery fracture energy. A primary goal of the project is to correlate biomechanical measurements with underlying tissue structure, particularly with those features which have been clinically associated with plaque rupture in humans. An additional goal is to apply analytical methods derived from classic fracture mechanics to the problem of plaque rupture.
If successful, this research will provide new experimental tools and computational approaches to study atherosclerotic plaque rupture, with an emphasis on small animal models. Application of 3-D DIC to measure local strains on the micrometer length scale is likely to find broad utility in mechanical studies of biological tissues. The project will offer an introduction to mechanical testing and data analysis to area high school students by providing an educational/laboratory experience module for the SCienceLab outreach program developed by the USC Center for Science Education. This SCienceLab module will be the first in the program to focus on engineering concepts. The project will also help to strengthen the newly established Biomedical Engineering Program at USC.
