The equilibrium and dynamic adsorption behavior of mixed lipid (DMPC and DMPG) vesicles on a hydrophilic silica bead substrate indicate that the adsorption is a two-step process. Vesicles initially adsorb and spread on the silica surface as lamellar bilayer discs, with a rate mediated by the charge-charge interactions between vesicles and the silica beads. Vesicle adsorption occurs more readily on the growing discs than on the bare silica surface, and consequently the adsorption rate increases as the discs grow. Eventually, the growth is arrested because of unfavorable charge interactions between the discs as they cover more of the surface, and the equilibrium condition of partial surface coverage is attained.
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