(403b) Coarse-Grained Models for Understanding Transport in Soft, Crowded Matrices

Within biological systems, macromolecular crowding affects the structure, assembly, and dynamics of proteins, biopolymers, and other nanoscopic constituents. Understanding these effects provides insight into biological function and enables new strategies for delivering drugs and theranostics. The transport processes of nanoscopic constituents are well-described by continuum theories when their size is much larger or much smaller than typical length scales within the crowded matrix. The continuum assumption breaks down, however, when the transported constituents are comparable in size to features of the matrix. In this limit, transport remains incompletely understood. In my talk, I will discuss our recent application of coarse-grained models to investigate particle transport in soft polymer matrices, as simplified models for crowded media. We use these models to elucidate the physical mechanisms responsible for the anomalous transport behavior that has been recently reported in complementary microscopy experiments. Our results show that these unusual dynamics arise due to the coupling of particle motions with comparably sized fluctuations in the surrounding matrix.