Transformation of phosphatidylcholine multilayer systems in a large excess of water

Hydration process of multi-stacked phospholipid bilayers to form giant vesicles

“…lamellar stack (maybe one by one), and form giant vesicles. The behavior of the late stage is consistent with the results by Hartung et al and Pabst et al [8,9,15]. However, the present process is much faster than their cases.…”

“…However, they examined this process by increasing temperature (not swelling with water) [14]. Hartung et al and Pabst et al have shown that the intensity of Bragg peak due to the regular stacking of bilayers decrease slowly with time when well-aligned phospholipid bilayers on a solid substrate are hydrated by excess water [8,15]. Although their results suggested that the bilayers peel off from the substrate and form vesicles, the process of hydration has not been clarified yet.…”

Adhesion of lipid membranes induced by CrCl 3

“…However, it seems that γ starts with a finite slope rather than a parabolic dependence, which speaks for a first-order transition. Another perhaps more convincing argument for a first-order transition is provided by the frequently observed metastability of PC multilayer systems in excess water [3][4][5]7]. It should be noted that the lateral tensions in the experiments are powers of ten above the range of so-called weak adhesion of vesicles [14,15].…”

“…They peel off, single or perhaps in bunches, from the multilayer system in excess water when upon water uptake its repeat distance has reached a characteristic value in the range of 65Å. The first experiments demonstrating that the so-called equilibrium period is not a stable state, in contrast to former ideas, were reported by Hartung et al [3]. Studying prehydrated disordered multilayer systems of palmitoyloleoyl PC (POPC), they found the X-ray diffraction signal of the fixed repeat distance in most samples to decrease and vanish within hours or days.…”

Cryo-transmission electron microscopy of a superstructure of fluid dioleoylphosphatidylcholine (DOPC) membranes

“…In recent small angle x-ray scattering experiments we found PC multilayer systems to disintegrate while the monitored repeat distance remained fixed at the so-called equilibrium spacing. This was taken to suggest that the membranes peel off the stack when they acquire the superstructure (Hartung et al, 1994). However, the most compelling reason for postulating a superstructure is the need to explain an anomalous membrane roughness that can absorb as much area again as is visible under the optical microscope (AA/A ' 1).…”