Differences in the physical properties of lipid monolayers and bilayers on a spherical solid support

Abstract

A monolayer of 1,2-dipalmitoyl-d62-glycero-3-phosphocholine (DPPC-d62) coated onto silanized silica beads (spherical supported monolayer: SSM) is studied by 2H-NMR and DSC. The results are compared with those obtained from a single bilayer on the same solid support (spherical supported vesicles: SSV) and from multilamellar vesicles (MLV). The phase transition temperature (Tm) of the SSMs is significantly higher than that of the bilayer systems and the extent of this difference depends on the lipid density in the monolayer that is determined during its preparation. 2H-NMR reveals a gel and fluid phase coexistence in the SSM transition region. A comparison of the 2H-NMR line shapes suggests the presence of highly curved structures for the fluid phase of the SSM samples. From a comparison of SSM and SSV transverse relaxation in the fluid phase we can conclude that the lateral diffusion coefficient D1 in supported monolayers is similar to that in bilayers.

Compression forces generated by actin comet tails on lipid vesicles

“…The surface of these beads is approximately as fluid as a simple lipid bilayer (36), but the beads are not deformable. We found substantial accumulation of ActA on the rear half of the bead, suggesting that the actin-dependent ActA polarization could occur independently of deformation ( Fig.…”

Dynamics of supported lipid bilayer deposition from vesicle suspensions

“…Two types of membranes that are particularly interesting are the so-called supported lipid bilayer (SLB) and supported lipid monolayer (SLM). An SLB is formed on a hydrophilic surface such as silica, quartz, oxidized silicon, and glass consists of two leaflets of phospholipids [6]. An SLM can be assembled on silane-derivatized silica surfaces [6,7] or thiol-coated gold surfaces [8][9][10][11][12], or it can be obtained by the covalent linking of chemically modified phospholipids with silica [13] or gold.…”

“…An SLB is formed on a hydrophilic surface such as silica, quartz, oxidized silicon, and glass consists of two leaflets of phospholipids [6]. An SLM can be assembled on silane-derivatized silica surfaces [6,7] or thiol-coated gold surfaces [8][9][10][11][12], or it can be obtained by the covalent linking of chemically modified phospholipids with silica [13] or gold. Another type of lipid monolayer, also called immobilized artificial membrane (IAM), can be obtained by the direct covalent bonding of phospholipid analogs on silica particles [14,15].…”

Selective Recognition of Co‐assembled Thrombin Aptamer and Docetaxel on Mesoporous Silica Nanoparticles against Tumor Cell Proliferation

“…The mean diameter of the obtained vesicles was about 160 nm. After mixing the vesicles with MSNs in phosphate buffered saline (PBS) above the phase inversion temperature of the mixed liposomes, according to the published method by Bayerls group, [33,34] the aptamer-phospholipid-Dtxl vesicles can be coated on the surface of MSNs ( Figure S1 C in the Supporting Information). In addition, to observe the co-assembled system, the prepared TBA A 15 -lipid-Dtxl-MSN were observed by confocal laser scanning microscopy (CLSM; Figure S2 in the Supporting Information).…”