Simulations of the Upper Critical Solution Temperature Behavior of Poly(ornithine-co-citrulline)s Using MARTINI-Based Coarse-Grained Force Fields

Poly(ornithine-co-citrulline)s are ureido-based polymers, which were shown to exhibit tunable upper critical solution temperature (UCST) behavior, a property that can be exploited develop thermoresponsive nanoparticles for controlled drug delivery systems. To gain insight into the driving forces govern formation and dissolution processes of poly(ornithine-co-citrulline) nanoparticles, molecular dynamics (MD) simulation study has been carried out using MARTINI-based protein coarse-grained models. Multi-microsecond simulations at temperatures ranging from 280 370 K show fully reparametrized version 3.0 MARTINI force field is able capture dependence on aggregation dissolution, while 2.2 could not account it. Furthermore, phase separation observed in these allowed us extrapolate diagram based Flory–Huggins theory polymer solution, help future rational design poly(amino acid)s.