January 26, 2018
Speaker: Amrinder Nain
Affiliation: Virginia Tech
Native fibrous proteins of small to large diameters (tens of nm to microns) distributed in various configurations (sparse/dense or random/aligned) form the complex and heterogeneous extracellular microenvironment (ECM). For cells to be able to navigate through this jungle of mismatched interfaces requires formation and exertion of forces by instantaneous cell-ECM protrusive events capable of spatiotemporal plasticity. Despite decades of in vitro studies, our knowledge of how cells sense, form and mature protrusions on fibers of varying diameters still remains in infancy. Thus, there exists a critical need to develop fiber-based platforms allowing for formation and study of individual protrusions in a repeatable and controlled manner. In this talk, I will discuss our approach of using suspended fibers of controlled curvatures (low: 2000 nm to high: 100 nm) for studying single protrusions at high spatiotemporal resolutions in-line with and also independent of cell-body migration direction. First, using aligned fiber networks coupled with Nanonet Force Microscopy (NFM) to measure forces exerted by cells, I will discuss our findings in (i) spatiotemporal distribution of focal adhesions during cell spreading along cell polarized direction, and (ii) the role of twine-bridges formed laterally to cell polarized direction. Second, using network of orthogonal fibers, I will discuss formation and isolation of individual protrusions independent of cell-body migration direction. In doing so, we are able to develop morphodynamic metrics that quantitatively show protrusions to be cell-specific, extremely sensitive to fiber curvature and for the tested cells intermediate filament vimentin is not required for formation of long protrusions.
Amrinder Nain is associate professor in the mechanical engineering department at Virginia Tech. He received his PhD in mechanical engineering from Carnegie Mellon University in 2007. Prior to graduate school, he worked in the semiconductor industry in precision design and robotics. He is the inventor of non-electrospinning Spinneret based Tunable Engineered Parameters (STEP) fiber manufacturing platform and Nanonet Force Microscopy (NFM). He is the director of STEP Lab at Virginia Tech with focus on advanced materials and mechanobiology.
Registrations are closed for this event.