Immuno-magnetoliposomes targeting activated platelets as a potentially human-compatible MRI contrast agent for targeting atherothrombosis

Dual Centrifugation - A Novel “in-vial” Liposome Processing Technique

“…Liposomes made by homogenization via VPG intermediates tend to have a higher lamellarity as seen by EM pictures [10,17]. The lamellarity can somewhat be influenced by the type of lipids used [10].…”

“…The lamellarity can somewhat be influenced by the type of lipids used [10]. Using lipids that ease the interactions between the surfaces of two membranes like PEG-carrying phospholipids leads to a higher lamellarity [17], whereby this interaction is further supported by the close vicinity of the membranes due to the low amount of water in the VPGs. In addition, also compounds to be entrapped may have an influence.…”

“…Dispersion of the VPGs allows the formation of normal liposomes by filling the preliposomes with additional water molecules, which can easily diffuse across the lipid membranes (Figure 2). Since in preliposomes the water molecules together with the water-soluble drug molecules were only distributed over the surfaces of the polar membranes, and since the surface area inside the liposomes is nearly as large as outside, it becomes clear that EE values up to 50% can be reached in the dispersed liposomal formulations [10,[15][16][17]. Schematic drawing of preliposomes in a VPG made by homogenization of a highly concentrated lipid-water mixture.…”

“…However, the average sizes of liposomes made by homogenization of highly concentrated lipid mixtures are small, but seldom below 100 nm with PI values > 0.2 (PCS (Photon Correlation Spectroscopy), intensity weighted 1 ) [10,[16][17][18][19][20][21]. At a first glance, this appears somewhat confusing, since it is known that the liposome diameters clearly depend on the energy by which the highly concentrated lipid-water mixture has been treated and thus, liposomes made by HPH would have been expected to be very small.…”

“…In MLVs, more of the membrane-associated, water-soluble drug molecules are entrapped due to the "entrapment" of additional membranes. Unfortunately, only a few articles reporting EE values >50% present also data on lamellarity-e.g., EM pictures [10,17] or NMR studies.…”