Molecular dynamics simulations of cold atmospheric plasma interactions with lipid bilayers

Cold atmospheric plasmas generate many reactive species that may degrade the cell wall and induce cell death. Models of species generation have been conducted for various plasmas, particularly for air plasmas¹. Oxidative species, including OH radicals, O, O₂, O₃, and H₂O₂, are some of the most effective species in damaging cell walls². Assessing and controlling the impact of these species on lipid membranes is complicated by an incomplete understanding of the species generated by a given plasma and the subsequent biophysical action with cell membranes and walls. We apply molecular dynamics (MD) to assess plasma-membrane interactions as a first step to guiding plasma device design. A well-established computational technique for studying membrane level interactions, MD simulations have been used to analyze reactive oxygen species interactions with bacterial cell wall peptide chains^2,3. Particle in a box models and atomistic structures enable the simulation of highly accurate interactions. The Large Scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) and the ReaxFF subroutine are very effective in membrane interactions simulations at both atomistic and coarse grained levels⁴. Here, we apply LAMMPS and ReaxFF to assess the interactions of various densities and energies of oxidative species with cell membranes. We further benchmark coarse grained models against atomistic simulations to enable more rapid screening of the membrane level interactions of various species to better guide future plasma simulations. Implications of direct (with membrane electric field) and indirect (without membrane electric field) application will be assessed.