Molecular Dynamics Simulation of Mixed Lipid Bilayer with DPPC and MPPC: Effect of Configurations in Gel-phase.

Abstract

Liposomes, spherical nanoparticles composed of phospholipid bilayers, have been suggested as a drug delivery system for potent chemotherapeutics. As the lipid structure transitions from gel to liquid-crystalline the structure reaches its maximum permeability, which then the encapsulated drugs can be released. As this phase transition occurs with changes in temperature, it has been suggested to incorporate lysolipid as part of the phospholipid bilayer systems to control this transition temperature. This study runs fully atomistic molecular dynamics (MD) simulations with flat liposome mixed-dispersed and mixed-island model. Mixed-dispersed model has lysolipid evenly distributed across the structure; Mixed-island model has lysolipid aggregated in the middle of the structure. The system is comprised of 10 percent lysolipid and 90 percent Dipalmitoyl Phosphatidyl Choline (DPPC). MonoPalmitoyl Phoshatidyl Choline (MPPC) is used as lysolipid. The changes in structure through the phase transition are investigated.