A coarse-grained model for amorphous and crystalline fatty acids.

Area of Science:

• Biophysics
• Materials Science
• Computational Chemistry

Background:

• Fatty acids are key components of the stratum corneum's lipid lamellae, forming the skin's barrier.
• Understanding the molecular structure of these lamellae is essential for elucidating skin mechanics.
• Current models lack detailed simulation capabilities for the solid phases of fatty acids.

Purpose of the Study:

• To develop a transferable coarse-grained model for fatty acids.
• To accurately represent both amorphous and crystalline states of fatty acids.
• To provide a foundation for molecular-level studies of skin barrier function.

Main Methods:

• Development of a coarse-grained model for fatty acids.
• Optimization of the force field using radial distribution functions from atomistic simulations.
• Application of the Reith, Putz, and Muller-Plathe method with a damping factor for improved convergence.
• Validation against both amorphous and crystalline fatty acid systems.

Main Results:

• A transferable coarse-grained force field for fatty acids in both amorphous and crystalline states was successfully developed.
• The model accurately reproduces radial distribution functions, preserving atomistic structural details.
• The amorphous force field effectively models mixtures of free fatty acids.
• This represents a novel coarse-grained model for studying solid phases of fatty acids.

Conclusions:

• The developed coarse-grained model provides a robust tool for simulating fatty acid systems.
• This model facilitates deeper molecular-level understanding of skin barrier mechanics.
• The approach is applicable to fatty acids of varying chain lengths and their mixtures.