Molecular dynamics study of the mechanical properties of drug loaded model systems: A comparison of a polymersome with a bilayer

GRILLO, DAMIÁN A.; ALBANO, JUAN M. R.; VALLADARES T., RUFINO E.; MOCSKOS, ESTEBAN E.; FACELLI, JULIO C.; PICKHOLZ, MÓNICA; FERRARO, MARTA B.

JOURNAL OF CHEMICAL PHYSICS

AMER INST PHYSICS

Año: 2023 vol. 159

0021-9606

n this work we implement a new methodology to study structural and mechanical properties of systems having spherical and planar symme-tries throughout Molecular Dynamics simulations. This methodology is applied here to a drug delivery system based in polymersomes, as anexample. The chosen model drug was the local anesthetic prilocaine due to previous parameterization within the used coarse grain scheme.In our approach, mass density profiles (MDPs) are used to obtain key structural parameters of the systems, and pressure profiles are used toestimate the curvature elastic parameters. The calculation of pressure profiles and radial MPDs required the development of specific methods,which were implemented in an in-house built version of the GROMACS 2018 code. The methodology presented in this work is applied tocharacterize poly(ethylene oxide)-poly(butadiene) polymersomes and bilayers loaded with the model drug prilocaine. Our results show thatstructural properties of the polymersome membrane could be obtained from bilayer simulations, with significantly lower computational costcompared to whole polymersome simulations, but the bilayer simulations are insufficient to get insights on their mechanical aspects, sincethe elastic parameters are canceled out for the complete bilayer (as consequence of the symmetry). The simulations of entire polymersomes,although more complex, offer a complementary approach to get insights on the mechanical behavior of the systems.