Investigation of Phase Transitions of DPPC Membrane Bilayers in the Presence of Fluorinated Decane Molecules Using Classical Molecular Dynamics Simulations

Perfluorinated molecules exhibit a distinctive physicochemical behavior known as fluorophilicity, which differs fundamentally from hydrophilicity and lipophilicity and governs their interaction with biological membranes. Understanding how fluorinated materials interact with lipid bilayers is essential due to their increasing use in biomedical and industrial applications. In this study, the membrane behavior in the presence of three decane derivatives-non-fluorinated decane (H10), partially fluorinated decane (H5F5), and fully fluorinated decane (F10)-was systematically investigated in a fully hydrated dipalmitoylphosphatidylcholine (DPPC) lipid bilayer. The simulation results demonstrate that fluorinated molecules enter the membrane more rapidly than non-fluorinated decane and exhibit reduced diffusion within the bilayer interior. Additionally, fluorinated decanes significantly increase the deuterium order parameter of the lipid alkyl chains, indicating enhanced chain ordering and a strong preference for all-trans conformations, particularly in the presence of F10. Fully fluorinated decane was found to embed deeply within the hydrophobic core of the membrane, where it induces noticeable lipid chain tilting and increases the area per lipid, as confirmed by density profile analysis. These findings indicate that fluorination substantially modifies membrane phase and dynamics, highlighting the critical role of fluorophilicity in membrane–molecule interactions. All-atom molecular dynamics simulations were performed on fully hydrated DPPC lipid bilayers containing each decane derivative under physiological temperature and pressure conditions. The systems were energy minimized and equilibrated prior to production runs. Standard force field parameters were applied for lipids and fluorinated hydrocarbons, and periodic boundary conditions were employed in all three spatial dimensions. Structural and dynamical properties were analyzed using mass density profiles, lateral diffusion coefficients, deuterium order parameters, lipid chain tilt angles, and area per lipid calculations. Trajectory analysis was carried out using built-in tools.