Development and analysis of image-based system for in-situ arterial pressurization

Mentor: Matthew Bersi, Assistant Professor, Department of Mechanical Engineering & Materials Science

Lab description: Research in the Bersi lab is generally focused on mechanisms of soft tissue remodeling in cardiovascular disease. Specific research interests include the
interplay between immune cell activation and the mechanobiology of vascular cells in the context of remodeling in response to intraluminal vascular injury, hypertension, and aneurysm. We are particularly interested in the role of T cell polarization along the Th17/Treg axis on promoting phenotyping alterations of vascular smooth muscle cells as well as the impact of cell-cell adhesion proteins (e.g., cadherin-11) on ardiovascular tissue remodeling. Techniques in the Bersi lab include small animal surgical models of cardiovascular disease, soft tissue mechanical testing and material characterization, optics-based approaches such as histology and whole-mount tissue imaging, in vitro assays for assessment of cellular phenotype, analysis of gene transcription, immune cell isolation and polarization, and mathematical modeling. Using a combination of engineering approaches and molecular biological tools, we are investigating disease progression and therapeutic approaches in cardiovascular medicine.

Project: Ongoing projects in the Bersi lab with opportunities for student involvement are related to the development of a system for in-situ arterial pressurization in the mouse. Biomechanical analysis is a common ex vivo technique used to determine mechanical properties of aortic tissues such as distensibility, stiffness, and stored elastic energy. Traditional approaches require that tested segments be removed from the body, cleaned of excess perivascular tissues, and mounted in devices capable of measuring quantities such as arterial pressure, force, and diameter. However, increasing evidence suggests that such perivascular structures provide non-negligible external mechanical support and may be an important reservoir for effector cells that have direct impacts on vascular mechanobiology. To circumvent these limitations of traditional biomechanical analysis, the current project seeks to develop an in-situ mechanical testing system comprised of controlled intravascular pressurization and image-based measurement of vascular deformation. Outcomes of this project will be focused on 1) biomechanical characterization of perivascular tissues in different regions of the aorta, 2) in-situ pressurization of small vascular segments that are not testable using standard methods, and 3) tissue deformation near aortic branch sites. Students working on this project will gain experience with biomechanical analysis of vascular tissues, optical coherence tomography imaging, image processing (including segmentation and quantification), small animal tissue dissection, and various molecular biology techniques including histology and/or gene expression analysis.