Young Innovators in Biomedical Engineering
Marsha W. Rolle, Ph.D.
Assistant Professor, Biomedical Engineering
Worcester Polytechnic Institute
September 27, 2011 11am—12pm,
Whitaker 1103
"Cell-Based Approaches to Vascular Tissue Engineering"

Over the past three decades, tissue engineering has emerged as a promising approach to create blood vessel sub-stitutes for clinical transplantation, as well as model systems to study vascular tissue function in vitro. Although the majority of vascular tissue engineering strategies rely on seeding cells on or within a biomaterial scaffold, cell-based (or "scaffold-less") methods have also been used to create tissue engineered blood vessels (TEBV). Cell-based approaches, in which tissues are constructed entirely from cells and cell-derived extracellular matrix (ECM), may yield TEBV that exhibit improved biocompatibility, higher cell density, and material properties that more closely mimic native blood vessels. However, the length of time required for ECM synthesis and tissue maturation (> 2 months), as well as the need for methods of assembling cells into 3D structures, have impeded the widespread use of cell-based TEBV. The goal of our research is to overcome these limitations by developing novel systems that achieve rapid self-assembly of cells to form cohesive 3D tissues which can be used for quanti-tative functional assessment of tissue structure and function.

Toward this goal, we have successfully grown cell-derived tubular constructs by direct cell seeding and culture on tubular mandrels or lateral fusion of ring-shaped tissue constructs formed by cellular aggregation and self-assembly. Both approaches generate cohesive tissue constructs within 14 days that exhibit mechanical properties similar to reported values for other engineered vascular tissues cultured statically for comparable times. Histo-chemical analysis suggests an abundance of glycosaminoglycan synthesis, with some collagen production, which appears to increase in quantity and organization with time in culture. Ongoing and future work focuses on screening culture parameters to optimize cell-based tissue function, as well as biochemical characterization of ECM composition and organization. These unique systems provide straightforward and versatile new tools for rapid fabrication and quantitative functional assessment of cell-derived tissues, and could lead to new systems for vascular tissue engineering and in vitro modeling of human vascular disease.

Dr. Rolle is being hosted by BME Associate Professor Todd McDevitt (todd.mcdevitt@bme.gatech.edu)