Mechanobiological Optimization of Vascular Grafts

Wednesday, May 10, 2023

4:00 PM-5:30 PM

BIOMED Seminar

Title:
Mechanobiological Optimization of Vascular Grafts

Speaker:
John Eberth, PhD
Associate Professor
School of Biomedical Engineering, Science & Health Systems
Drexel University

Details:
Autografts remain the standard-of-care for small-diameter vascular procedures with transplanted tissues experiencing profound remodeling in order to function effectively in the coronary environment. Fortunately, the blood vessel microarchitecture is responsive to subtle mechanobiological cues that can initiate favorable remodeling processes. These include but are not limited to, the expression of anti-inflammatory and anti-thrombotic genes, the synthesis and removal of extra-cellular-matrix proteins, and the eventual quiescence of smooth muscle cells. However, severe biomechanical incompatibilities (e.g., compliance mismatch) underly several vascular etiologies, including ischemia, hemorrhage, inflammation, and restenosis.

Ultimately, the mechanobiological factors driving adaptive or maladaptive remodeling may be deterministic in bypass graft outcomes. In this presentation, novel tools, techniques, and experiments are described to quantify and alter functional blood vessel histomechanics from several autologous porcine source vessels and their coronary targets.

Data from these experiments were used within a continuum mechanics framework to fit a structurally motivated, nonlinearly elastic, collagen fiber reinforced, anisotropic constitutive model using bootstrapping statistical techniques and the theory of “small-on-large” to improve the physical interpretation of cellular mechanosensing. Constitutive models were then used to inform finite element and, subsequently, computational fluid dynamic simulations revealing the fluid-solid penalties occurring at the anastomotic junction of graft-host mismatched tissues. Ongoing studies seek to quantify the pro-thrombotic and pro-inflammatory costs associated with mismatching.

Biosketch:
John F. Eberth, PhD, is an Associate Professor in Drexel University’s School of Biomedical Engineering, Science and Health Systems (BIOMED). He recently relocated to Drexel from the University of South Carolina’s School of Medicine, where he held appointments in Cell Biology and Anatomy and was a core member of the Biomedical Engineering program. His formal training includes BS and MS degrees in Mechanical Engineering, a PhD in Biomedical Engineering from Texas A&M, and a Bioengineering postdoctoral fellowship from Rice University.

To date, Dr. Eberth has authored ~50 peer-reviewed manuscripts and book chapters on cardiovascular growth and remodeling, aneurysm mechanics, arterial stiffening, perfusion tissue culture, cardiac development, congenital heart defects, hydrogel mechanics, and tissue-engineered vascular grafts. Research in his Applied Biomechanics and Mechanobiology Lab is currently supported by multiple grants from the NIH, NSF, and other private sources to study vascular inflammation, aortic aneurysm attenuation, endothelial dysfunction, and medial calcification chelation therapy.

Contact Information

Lisa Williams
ltw22@drexel.edu