Fig. 6

Molecular Dynamics simulations. a, b Cluster formation of PpIX in solution. Clusters are comprised of stacked PpIX molecules forming rod-like structures. An isolated stack is depicted in b. c The organization of PpIX in these rods occurs in defined pattern. Neighboring molecules are either 90 degree or 270  rotated against each other while a 0 or 180 rotation is not permitted. d, e C8-EDTA interacts with the cluster but assembles on the surface of the PpIX cluster. No C8-EDTA was found to penetrate the stacked molecules as shown in e. f C14-EDTA can penetrate in-between the layers of the PpIX stacks. g Zoomed version of the C14-EDTA cluster where the hydrophobic tail penetrates in-between the neighboring PpIX molecules. h EDTA does not penetrate between the layers of the PpIX stacks. (i) SDS forms a co-existing cluster that is attached to PpIX. j The Martini simulations with 2000 PpIX molecules show the formation of large, nanometer-sized clusters. k Small aggregates form in the presence of C14-EDTA