(225g) Polymers in a Cage: Effect of Surroundings On Partial Confinement

Recent years have seen a renewed interest on the properties of the confined polymers for their close connection to biological processes such as genome packaging in viral capsids and chaperone-assisted protein folding in bacterial cells. Unlike polymers near a surface or at conventional inhomogeneous conditions, a confined biomacromolecule remains in contact with a cellular milieu and its properties depend not only on the geometry of the confining space that restricts the chain conformation but also on the local cellular environment that favors the biomacromolecule packaging. The effect of environment on the properties of a confined biomacromolecule is often ignored in previous theoretical investigations. In this work, we use the polymer density functional theory (DFT) to study the structure and thermodynamic properties of polymers in a spherical cage and investigate how these properties are affected by the surroundings that mimic the macromolecule ?crowding? effect. We will show that the theoretical predictions are in good agreement with Monte Carlo simulation data for the density distribution of confined single chain. For a single chain partially confined in a spherical cage, we demonstrate how the equilibrium state is affected by the surroundings and the non-equivalence of the osmotic pressure outside and inside of the cavity.