Speaker
Description
Aggregates of lipids in living systems can range over several magnitudes in their size. The first choice of and most trustable modelling certainly is molecular dynamics, where a system is fully populated by molecules made from individual, interacting particles, providing by their trajectories aggregate behavior and means for detailed study. For the resource-constrained lipid scientist though, the computational cost of these simulations limits the dimensions of the investigated systems to the microscopic scale -even if coarse-graining is employed. For this reason we follow the suggestion by Ito et al. to approximate amphiphilic lipid molecules in an aqueous environment by a copolymer-homopolymer mixture, more precisely by the respective Ohta-Kawasaki model. The simplification still captures key aggregate properties by means of coupled phase-fields over the full range of length scales. To this end, we parametrize the phenomenologically assumed phase-field model for the prototypical DPPC lipid in water, using information derived from according molecular data and a combination of gradient-free methods, classification and interpolation. By this simplistic approach, we are able to approximate the steady state predicted patterns anticipated for this type of lipid in contact with water, and thus enable comparatively economic studies of the plethora of lipid aggregates.
