Role of High-Order Hydrodynamic Interaction of Semiflexible Filament Dynamics

Abstract

Biopolymers like collagen, actin, microtubules, and aggrecan play a structural role in cells and tissues. They are considered semiflexible polymers because their bending stiffness is on the order of, and resists, the Brownian forces that randomize their conformation. The study of the collective dynamics of semiflexible assemblies has come to prominence because it underlies the physics of force-transmission and mechanotransduction in cells and tissues. We had previously proposed modeling a semiflexible filament as a string of beams that bend continuously under Brownian forces (Chandran et al, 2009). This idealization not only captures the high-order nonlinear bending of the filament, but it does so at reduced computational cost compared to current string-of-beads idealizations. We had also proposed solving the relative solvent velocity along the filament as an implicit variable; which is equivalent to including several orders of hydrodynamic interaction and solvent-back reflection in the polymer dynamics (Chandran et al, 2010). In this presentation we compare the predictions of the string-of-beams model with implicit hydrodynamics against that of string-of-beads approaches for new insight on semiflexible polymer dynamics that is produced by the higher-order bending and interaction terms.