Multivalent ion effects on electrostatic stability of virus-like nano-shells

TL;DR

This paper investigates how multivalent ions influence the electrostatic stability of virus-like nano-shells, combining theoretical modeling with simulations to understand forces affecting viral capsid stability in various ionic conditions.

Contribution

It introduces a theoretical model using the dressed multivalent ion approximation and validates it with Monte-Carlo simulations, elucidating ion effects on nano-shell stability.

Findings

Model accurately predicts electrostatic pressure for certain charge densities and salt concentrations.

Electrostatic pressure can be positive or negative, indicating outward or inward forces on the shell.

Ionic environment critically affects viral shell stability and assembly.

Abstract

Electrostatic properties and stability of charged virus-like nano-shells are examined in ionic solutions with monovalent and multivalent ions. A theoretical model based on a thin charged spherical shell and multivalent ions within the "dressed multivalent ion" approximation, yielding their distribution across the shell and the corresponding electrostatic (osmotic) pressure acting on the shell, is compared with extensive implicit Monte-Carlo simulations. It is found to be accurate for positive or low negative surface charge densities of the shell and for sufficiently high (low) monovalent (multivalent) salt concentrations. Phase diagrams involving electrostatic pressure exhibit positive and negative values, corresponding to an outward and an inward facing force on the shell, respectively. This provides an explanation for the high sensitivity of viral shell stability and self-assembly of viral capsid shells on the ionic environment.