Brown University School of Engineering

Engineering Seminar: Biomedical Engineering

Thursday, September 19, 2019

9:00am - 10:00am

School of Engineering

Barus and Holley, 190

Elizabeth Cosgriff-Hernandez, Professor of Biomedical Engineering, L.B. (Preach) Meaders Professorship in Engineering, University of Texas at Austin, will present a talk: “Strategic Biomimicry in the Design of Multilayer Vascular Grafts.”

Abstract: Tissues have evolved to have complex function derived from the hierarchical structure of the tissue, from protein sequence to macroscale architecture. Achieving this level of structural complexity and function with synthetic materials continues to be challenging. Rather than attempting to fully replicate the complexity of tissue structures, identification of which structure-property relationships drive clinical success can be used to better inform biomaterial design. Polymer chemistry and engineering can then be used to target specific biomaterial design criteria expected to improve clinical outcomes. As a representative example, a major roadblock in off-the-shelf vascular graft development is achieving rapid endothelialization of the lumen while minimizing the risk of thrombosis, intimal hyperplasia, and mechanical failure. However, matrix properties which promote graft endothelialization may not be consistent with those appropriate to sustain the loads associated with adult vasculature. To address this limitation, we have developed multilayered hydrogelelectrospun mesh scaffolds in which a hydrogel layer provides a local microenvironment inductive of rapid endothelialization and an electrospun mesh sleeve provides bulk strength, compliance matching, and suture retention. Thus, each component can be individually tuned to achieve improved outcomes without detriment to other design goals and then bonded together into composite grafts. Collagen IV served as a design basis for the hydrogel layer due to its putative role in regulating endothelial cell adhesion and phenotype; however, native collagen demonstrates significant batch variability and is thrombogenic.