(523j) Exploring the Effects of Osmolytes on Complex Coacervation

Coacervation is an associative liquid-liquid phase separation phenomenon that takes place due to the electrostatic complexation of oppositely-charged polymers and the entropic gains associated with the release of bound counterions. The importance of electrostatic interactions in coacervate systems has meant that studies investigating the phase behavior of these systems have tended to focus on parameters such as the charge stoichiometry of the polymers, the solution pH, and the ionic strength. However, the equilibrium that exists between the polymer-rich coacervate phase and the polymer-poor supernatant represents a balance between attractive electrostatic interactions and excluded volume repulsions. We hypothesize that the addition of osmolytes can tune coacervate phase behavior. However, an important consideration is whether the osmolytes partition preferentially into the coacervate or supernatant phase, as this affects the osmotic pressure balance in the system, and therefore the extent of the coacervation. In particular, our work focuses on small molecule osmolytes such as sugars, amino acids, as well as neutral polymers such as polysaccharides and poly(ethylene glycol) that have particular relevance in the formulation and stabilization of vaccines and therapeutics.

Acknowledgement:

This work was supported by NIH grant 1R21AI150962-01.