Hybrid Monte Carlo / Self-Consistent Field Theory for Modeling Zwitterionic Polymers

The antifouling and biocompatibility properties of zwitterionic polymers have led to their use in surface modifications in biotechnological applications. Surfaces modified with zwitterionic polymer brushes have been shown to exhibit ultralow fouling properties. Zwitterionic polymer conjugation has been used to stabilize therapeutic proteins. The antifouling and stabilizing properties of zwitterionic polymers are hypothesized to be due to the strong hydration exhibited by the zwitterions. Theoretical models for describing zwitterionic polymers behavior are currently lacking. In this work we present a hybrid Monte-Carlo simulation and Self-Consistent Field Theory to model zwitterionic polymers in solution and on the surface. This hybrid approach has been successfully employed in modeling complex coacervation. We apply coarse-grained modeling in an NVT MC simulation with Widom Insertion to generate free energy landscapes for a polymer, salt, and solvent system. These landscapes are used to inform a SCFT describing the system. This approach allows us to capture phase behavior in solution, as well as interfacial properties on the surface. This formalism can be extended to describe interactions with other charged species such as aptamers and polypeptides.