Abstract: The structural and mechanical properties of biological soft matter (i.e. biopolymers, cells, bacterial biofilms, tissues) are often connected to cellular function and disease states. However, there is frequently a gap in the understanding of the biophysical contributions to systems level behavior. Determining the physical behaviors of biological soft matter contributes to addressing this knowledge gap and guides the development of novel therapeutic and diagnostic tools that exploit the physical properties of biological systems. In this seminar, I demonstrate the utilization of a soft matter approach to address two clinically relevant problems: a) bacterial infection prevention and control, and b) metastatic cancer diagnosis and assessment.
First, I consider bacterial biofilms—structured communities of cells encapsulated in matrix materials that are frequently responsible for clinical infections—as a biocolloidal system, where the cells are analogous to colloidal particles and the matrix materials are analogous to a viscoelastic hydrogel. I discuss the impact of environmental stressors on the colloidal microstructure of bacterial biofilms, the use of artificial biofilms to establish the role of self-assembly in biofilm mechanics and dispersion, and the dependence of multispecies biofilm structural and growth behaviors on growth environment. My findings on the structure and mechanics of biofilms have implications in the field of biofilm microbiology and in the practice of biofilm infection prevention and control. Next, I explore the relationship between cellular mechanics and ovarian cancer metastasis. I demonstrate the use of microfluidic deformability cytometers for the high-throughput testing of cancer cell deformability. I assess the mechanics of ovarian cancer cells from primary and metastatic tumors and discuss potential biological mechanisms to explain differences in their biomechanical behaviors. This work advances the understanding of ovarian cancer biomechanics and demonstrates the use of deformability cytometers as potential cancer diagnostic and prognosis assessments.
Bio: Elizabeth J. Stewart is an Assistant Professor in the Chemical Engineering Department at Worcester Polytechnic Institute. She joined WPI after completing her PhD in Chemical Engineering at the University of Michigan and postdoctoral studies in the Department of Materials Science and Engineering at the Massachusetts Institute of Technology. Her work focuses on exploring and exploiting the physical properties of biological soft matter with a particular emphasis on bacterial infection prevention and control. She also has interests in studying interdisciplinary learning within graduate engineering education.