Filamentous Viruses as Probes of Polymer Solution Structure and Dynamics*

We examine the diffusive transport of highly anisotropic, filamentous viruses in semidilute solutions of near-neutral and charged polymers, in which length scales and dynamics can be systematically tuned through polymer concentration and solution conditions. Like spherical nanoparticles, the viruses diffuse faster than expected based on the bulk solution viscosity, and the deviation increases with polymer concentration. We show that the dynamics of viruses are affected both by anisotropy, which alters the hydrodynamic coupling to the polymer dynamics along and normal to the virus's long axis, and by flexibility. Further, we show that virus dynamics are sensitive to solution properties arising from electrostatic interactions between charged polymers. Our results provide insight into the transport properties of viruses in complex media ranging from membranes and to biopolymer solutions.