Discovery Park Undergraduate Research Internship Program

"Investigating Early Development of Murine Aneurysms"

About the Project

Project Time & Type:
Summer 2016 - DURI
Research area(s):
Biomedical Engineering
Project Description:
The apolipoprotein E knockout (apoE-/-) mouse model has been invaluable for studying the progression of cardiovascular disease. Researchers have used this model to study the physiological effects of exogenous delivery of angiotensin II (AngII), a peptide hormone causing vasoconstriction and hypertension. Abdominal aortic aneurysms (AAAs) are focal dilatations of the abdominal aorta and develop as dissecting aneurysms in apoE-/- mice infused with AngII. An improved understanding of the cause and progression could help AAA patients. In vivo imaging of preclinical vascular disease models has been largely underutilized, but it can greatly benefit cardiovascular research. Male apoE-/- C57BL/6J mice were subcutaneously implanted with AngII-loaded miniosmotic pumps (1000 ng/kg/min). We obtained longitudinal in vivo imaging data using high-frequency small animal ultrasound. We found that not only morphological, but also biomechanical and hemodynamic changes occur during initial AAA formation and subsequent growth. The intramural thrombus that forms in this model evolves in morphology and grows in volume with high degrees of heterogeneity. Regional differences in mean blood flow velocity are apparent down the length of aneurysms, and mean velocity decrease over time as the total AAA volume increases. Furthermore, circumferential cyclic strain significantly decreases upon initial aortic expansion and remains reduced throughout progression. We aim to further investigate the heterogeneity of AAA development using computational pulsatile flow models built from our in vivo ultrasound datasets. These models will provide information on site-specific changes in wall shear stress and oscillatory shear index, which are potentially predictive metrics for intramural thrombus formation and AAA growth.
Expected Student Contributions:
The intern will work with rodents to collect imaging data of abdominal aortic aneurysms. This will include use of a high frequency ultrasound system and simple surgical procedures to induce AAAs.
Related Website(s):
Desired Qualifications:
Strong background in rodent handling, high frequency ultrasound imaging, and data analysis.
Estimated Weekly Hours:
Department awards independent research credits for this project?

Professor in Charge

Goergen, Craig
biomedical engineering

Student Supervisor

Evan Phillips
PhD Graduate Student

Cooperating Faculty

Pavlos Vlachos
Mechanical Engineering/Engineering