Lanthanide ions such as La3+ and Gd3+ are well known to have large effects on the structure of phospholipid membranes. Unilamellar vesicles of dipalmitoylphosphatidylcholine (DPPC) were prepared by sonication method and confirmed by transmission electron microscopy. The effects of concentration of gadolinium ions Gd3+ on DPPC unilamellar vesicles in aqueous media were studied by different techniques. As physical techniques, photon correlation spectroscopy, electrophoretic mobility, and differential scanning calorimetry were used. The theoretical predictions of the colloidal stability of liposomes were followed using the Derjaguin-Landau-Verwey-Overbeek theory. Changes in the size of liposomes and high polydispersities values were observed as Gd3+ concentration increases, suggesting that this cation induces the aggregation of vesicles. Electrophoretic mobility measurements on unilamellar vesicles as a function of Gd3+ ion concentration show that the vesicles adsorb Gd3+ ions. Above Gd3+ concentrations of 0.1 mol dm-3, the zeta potential and light scattering measurements indicate the beginning of aggregation process. For comparison with similar phospholipids, the zeta potential of phosphatidylcholine interacting with Gd3+ was measured, showing an analogous behavior. Differential scanning calorimetry has been used to determine the effect of Gd3+ on the transition temperature (Tc) and on the enthalpy (DeltaHc) associated with the process.
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http://dx.doi.org/10.1103/PhysRevE.74.031913 | DOI Listing |
Gels
January 2025
Institute of Synthetic Bioarchitectures, Department of Bionanosciences, University of Natural Resources and Life Sciences, Vienna, Muthgasse 11, Level 2, 1190 Vienna, Austria.
Giant unilamellar vesicles (GUVs) are versatile cell models in biomedical and environmental research. Of the various GUV production methods, hydrogel-assisted GUV production is most easily implemented in a typical biological laboratory. To date, agarose, polyvinyl alcohol, cross-linked dextran-PEG, polyacrylamide, and starch hydrogels have been used to produce GUVs.
View Article and Find Full Text PDFBiomimetics (Basel)
January 2025
Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska Dolina F1, 84248 Bratislava, Slovakia.
The properties of the large unilamellar vesicles (LUVs) from 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC), modified by lipopolysaccharides (LPS) from sv. Enteritidis, which mimics Gram-negative bacteria, were studied by various physical methods. LPS, in the range of 0/20/50 % / relative to the lipid, had a regulatory role in the structure of the LUVs toward the lower size, low polydispersity, and over-a-month size stability due to the lower negative zeta potential.
View Article and Find Full Text PDFFront Mol Biosci
January 2025
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, United States.
This study investigates the dynamics of oleate hydratase (OhyA), a bacterial flavoenzyme from , and its interactions with lipid membranes, focusing on the factors influencing membrane binding and oligomerization. OhyA catalyzes the hydration of unsaturated fatty acids, playing a key role in bacterial pathogenesis by neutralizing host antimicrobial fatty acids. OhyA binds the membrane bilayer to access membrane-embedded substrates for catalysis, and structural studies have revealed that OhyA forms oligomers on membrane surfaces, stabilized by both protein-protein and protein-lipid interactions.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick, Canada.
Giant unilamellar vesicles (GUVs) are ideal for studying cellular mechanisms due to their cell-mimicking morphology and size. The formation, stability, and immobilization of these vesicles are crucial for drug delivery and bioimaging studies. Separately, metal-organic frameworks (MOFs) are actively researched owing to their unique and varied properties, yet little is known about the interaction between MOFs and phospholipids.
View Article and Find Full Text PDFLangmuir
January 2025
Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), Institute of New Concept Sensors and Molecular Materials, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Solid supported lipid bilayers (SLBs) serve as an excellent platform for biophysical studies. However, the formation of highly negatively charged SLBs on negatively charged surfaces remains a challenge due to electrostatic repulsion. Here, we study the effects of ionic strength and osmotic stress on the formation of highly negatively charged SLBs on the silica surface.
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