Bio-mechanical studies of normal and aging arterial wall

点击翻译按钮获取中文摘要

The aorta is the largest vessel in the body, exiting the heart and carrying oxygen-rich blood to cells in all other regions of the anatomy. Essentially, the aorta is a cylindrical tube with smooth walls and is extremely strong. Yet, it starts losing strength with age. This is associated with an overall decrease of the tissue organization with loss of elastin, which is the primary load bearing element, along with an increase of other less desirable components. The proposed research will answer the following fundamental questions: (a) how do we monitor the properties (for example stiffening) of blood vessels across the lifespan? (b) can we develop methods to estimate these properties from images without the need for actual mechanical tests? and (d) what are the molecular processes that occur in arterial tissues as they age, and can they be `recognized' from their imaging and flow signatures? The specific five-year objectives are as follows: 1.Develop and test a new mathematical model for healthy arterial tissue that describes changes due to growth (remodelling) and aging. 2.Develop techniques to estimate local arterial wall stiffness - by properly linearizing the constitutive model - and flow patterns, in vivo. 3.Study cell signalling and inflammatory processes which are part of the physiological remodelling processes in healthy arterial tissues. The advantage of this research is that it will make it possible to follow changes in the properties of healthy arteries. Most healthy tissues cannot be obtained from the general population and the amount and quality of tissues obtained from autopsy is limited. Therefore non-invasive techniques offer a unique opportunity. Moreover, current methodologies that monitor stiffening of arteries (for example pulse-wave velocity) do not link them to the micro-structural components and do not allow assessment of the in vivo stretch. This is important because higher pressure may manifest itself as increased apparent stiffness without changes in the tissue property. A new constitutive model capable of describing both remodelling and aging will be proposed and applied. Outcomes will be atlases of normal and aging aortas which could be used to achieve early diagnoses and eventually prioritize treatment options. This project will prepare undergraduate, graduate and post-doctoral trainees in interdisciplinary research. The students will build expertise in mathematical modelling, non-linear mechanics, fluid mechanics, biology, microscopy and statistical methodologies. They will build knowledge at the boundaries of engineering and natural science with a strong focus on critical thinking. These skills are translatable in many disciplines both in the area of bioengineering, as well as outside, in composite mechanics and polymeric material science, for example.