Role of Hydrophobic and Hydrophilic Interactions of Organotin and Organolead Compounds with Model Lipid Membranes

1997 ◽  
Vol 52 (3-4) ◽  
pp. 209-216 ◽  
Author(s):  
Janina Gabrielska ◽  
Janusz Sarapuk ◽  
Stanisław Przestalski
Keyword(s):  
Lipid Bilayer ◽  
Organic Compounds ◽  
Lipid Membranes ◽  
Model Membranes ◽  
Model Lipid Membranes ◽  
Cationic Detergents ◽  
Mechanism Of Interaction ◽  
Organolead Compounds ◽  
Planar Membranes

AbstractThe present study was conducted to clarify the mechanism of toxicity of organic compounds using lipid model membranes (liposomes and planar lipid membranes).The compounds studied were trialkyltin and trialkyllead chlorides, dialkyltin dichlorides and some inorganic forms of those metals. Two different (anionic and cationic) detergents were also used in the experiments to change the surface properties of liposomes. As a measure of interaction between the compounds studied and model membranes were the release of liposome bound praseodymium and the change in stability of planar membranes under the influence of those compounds.On the basis of the results obtained it was postulated that the mechanism of interaction between tin-and leadorganics and model lipid membranes is a combination of different factors featuring interacting sides. The most important properties determining the behaviour of organic compounds in the interaction were lipophilicity and polarity of different parts of the organics and the steric arrangement they can take in the medium. On the other hand, the surface potential of the lipid bilayer and the environment of the lipid molecules, that play a significant role in the availability of the lipid bilayer to the organics, were important factors in the interaction.

scholarly journals Comparison of the interactions of daunorubicin in a free form and attached to single-walled carbon nanotubes with model lipid membranes

2016 ◽  
Vol 7 ◽  
pp. 524-532 ◽  
Author(s):  
Dorota Matyszewska
Keyword(s):  
Carbon Nanotubes ◽  
Lipid Membranes ◽  
Hydrophobic Interactions ◽  
Drug Carrier ◽  
Surface Concentration ◽  
Free Drug ◽  
Model Membranes ◽  
Free Form ◽  
Comparable Amount ◽  
Model Lipid Membranes

In this work the interactions of an anticancer drug daunorubicin (DNR) with model thiolipid layers composed of 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) were investigated using Langmuir technique. The results obtained for a free drug were compared with the results recorded for DNR attached to SWCNTs as potential drug carrier. Langmuir studies of mixed DPPTE–SWCNTs-DNR monolayers showed that even at the highest investigated content of the nanotubes in the monolayer, the changes in the properties of DPPTE model membranes were not as significant as in case of the incorporation of a free drug, which resulted in a significant increase in the area per molecule and fluidization of the thiolipid layer. The presence of SWCNTs-DNR in the DPPTE monolayer at the air–water interface did not change the organization of the lipid molecules to such extent as the free drug, which may be explained by different types of interactions playing crucial role in these two types of systems. In the case of the interactions of free DNR the electrostatic attraction between positively charged drug and negatively charged DPPTE monolayer play the most important role, while in the case of SWCNTs-DNR adducts the hydrophobic interactions between nanotubes and acyl chains of the lipid seem to be prevailing. Electrochemical studies performed for supported model membranes containing the drug delivered in the two investigated forms revealed that the surface concentration of the drug-nanotube adduct in supported monolayers is comparable to the reported surface concentration of the free DNR incorporated into DPPTE monolayers on gold electrodes. Therefore, it may be concluded that the application of carbon nanotubes as potential DNR carrier allows for the incorporation of comparable amount of the drug into model membranes with simultaneous decrease in the negative changes in the membrane structure and organization, which is an important aspect in terms of side effects of the drug.

scholarly journals Characterizing the Structure and Interactions of Model Lipid Membranes Using Electrophysiology

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 319
Author(s):  
Joyce El-Beyrouthy ◽  
Eric Freeman
Keyword(s):  
Electric Fields ◽  
Self Assembly ◽  
Lipid Membranes ◽  
Model Membranes ◽  
Membrane Properties ◽  
Supported Membranes ◽  
Membrane Assembly ◽  
Model Lipid Membranes ◽  
Assembly Technique ◽  
Assembly Principles

The cell membrane is a protective barrier whose configuration determines the exchange both between intracellular and extracellular regions and within the cell itself. Consequently, characterizing membrane properties and interactions is essential for advancements in topics such as limiting nanoparticle cytotoxicity. Characterization is often accomplished by recreating model membranes that approximate the structure of cellular membranes in a controlled environment, formed using self-assembly principles. The selected method for membrane creation influences the properties of the membrane assembly, including their response to electric fields used for characterizing transmembrane exchanges. When these self-assembled model membranes are combined with electrophysiology, it is possible to exploit their non-physiological mechanics to enable additional measurements of membrane interactions and phenomena. This review describes several common model membranes including liposomes, pore-spanning membranes, solid supported membranes, and emulsion-based membranes, emphasizing their varying structure due to the selected mode of production. Next, electrophysiology techniques that exploit these structures are discussed, including conductance measurements, electrowetting and electrocompression analysis, and electroimpedance spectroscopy. The focus of this review is linking each membrane assembly technique to the properties of the resulting membrane, discussing how these properties enable alternative electrophysiological approaches to measuring membrane characteristics and interactions.

scholarly journals Binding of amphiphilic and triphilic block copolymers to lipid model membranes: the role of perfluorinated moieties

Soft Matter ◽  
2014 ◽  
Vol 10 (33) ◽  
pp. 6147-6160 ◽  
Author(s):  
Christian Schwieger ◽  
Anja Achilles ◽  
Sven Scholz ◽  
Jan Rüger ◽  
Kirsten Bacia ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Lipid Membranes ◽  
Model Membranes ◽  
Amphiphilic Block Copolymers ◽  
End Caps

Attachment of fluorophilic end caps to amphiphilic block copolymers increases their interaction with lipid membranes and enables the polymer's translocation.

Role of hydrophobic interactions in the fusion activity of influenza and sendai viruses towards model membranes

1994 ◽  
Vol 14 (1) ◽  
pp. 15-24 ◽  
Author(s):  
João Ramalho-Santos ◽  
Ricardo Negrão ◽  
Maria da Conceição Pedroso de Lima
Keyword(s):  
Lipid Membranes ◽  
Hydrophobic Interactions ◽  
Polymer Concentration ◽  
Viral Envelope ◽  
Fusion Process ◽  
Fusion Activity ◽  
Enveloped Viruses ◽  
Model Lipid Membranes ◽  
Poly Ethylene

We have studied the role of hydrophobic interactions in the fusion activity of two lipid enveloped viruses, influenza and Sendai. Using the fluorescent probe ANS (1-aminonaphtalene-8-sulfonate) we have shown that low-pH-dependent influenza virus activation involves a marked increase in the viral envelope hydrophobicity. The effect of dehydrating agents on the fusion activity of both viruses towards model lipid membranes was studied using a fluorescence dequenching assay. Dehydrating agents such as dimethylsulfoxide and dimethylsulfone greatly enhanced the initial rate of the fusion process, the effect of dimethylsulfone doubling that of dimethylsulfoxide. The effect of poly(ethylene glycol) on the fusion process was found to be dependent on the polymer concentration and molecular weight. In general, similar observations were made for both viruses. These results stress the importance of dehydration and hydrophobic interactions in the fusion activity of influenza and Sendai viruses, and show that these factors may be generally involved in membrane fusion events mediated by many other lipid enveloped viruses.

The modulating effect of lipid bilayer/p-coumaric acid interactions on electrical properties of model lipid membranes and human glioblastoma cells

2019 ◽  
Vol 92 ◽  
pp. 103242 ◽  
Author(s):  
Monika Naumowicz ◽  
Magdalena Kusaczuk ◽  
Marcin Andrzej Kruszewski ◽  
Miroslav Gál ◽  
Rafał Krętowski ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Lipid Bilayer ◽  
Lipid Membranes ◽  
Coumaric Acid ◽  
Glioblastoma Cells ◽  
Human Glioblastoma ◽  
Model Lipid Membranes ◽  
Human Glioblastoma Cells

scholarly journals Molecular Dynamics Simulation of the Interaction Between Benzanthrone Dye and Model Lipid Membranes

2020 ◽  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Fluorescent Dyes ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Membrane Composition ◽  
Model Lipid Membranes

The benzanthrone fluorescent dyes are known as environmentally-sensitive reporters for exploring the physicochemical properties and structural alterations of lipid membranes. In the present work the 100-ns molecular dynamics simulation (MD) was used to characterize the bilayer location and the nature of interactions between the benzanthrone fluorescent dye ABM and the model lipid membranes composed of the zwitterionic lipid phosphatidylcholine (PC) and its mixtures with the anionic lipid phosphatidylglycerol (PG20) and sterol cholesterol (Chol30). The MD simulations were performed in the CHARMM36m force field using the GROMACS package. The ABM molecule, which was initially placed at a distance of 30 Å from the midplane of the lipid bilayer, after 10 ns of simulation was found to be completely incorporated into the membrane interior and remained within the lipid bilayer for the rest of the simulation time. The analysis of the MD simulation results showed that the lipid bilayer location of the benzanthrone dye ABM depends on the membrane composition, with the distance from bilayer center being gradually shifted from 0.78 nm in the neat PC bilayer to 0.95 nm and 1.5 nm in the PG- and Chol-containing membranes, respectively. In addition, the partitioning of the ABM into the neat PC bilayer was followed by the probe translocation from the outer membrane leaflet to the inner one. A separate series of MD simulations was aimed at examining the ABM influence on the lipid bilayer structure. It was found that ABM partitioning into the lipid bilayers of various composition has no significant effect on the orientation of the fatty acid chains and leads only to a small increase of the deuterium order parameter for the carbon atoms 5-to-8 in the sn-2 acyl chains of the neat PC membranes. In addition, the interaction of the ABM with the model lipid membranes caused the slight decrease of the surface area per lipid pointing to the slight increase of the packing density of lipid molecules in the presence of ABM. The results obtained provide a basis for deeper understanding of the membrane interactions of benzanthrone dyes and may be useful for the design of the novel fluorescent probes for membrane studies.

scholarly journals Lipid Self-Assemblies under the Atomic Force Microscope

2021 ◽  
Vol 22 (18) ◽  
pp. 10085
Author(s):  
Aritz B. García-Arribas ◽  
Félix M. Goñi ◽  
Alicia Alonso
Keyword(s):  
Lipid Membranes ◽  
Lipid Membrane ◽  
Domain Size ◽  
Model Membranes ◽  
Model Systems ◽  
Systems Model ◽  
Atomic Force ◽  
Model Lipid Membranes ◽  
The Impact

Lipid model membranes are important tools in the study of biophysical processes such as lipid self-assembly and lipid–lipid interactions in cell membranes. The use of model systems to adequate and modulate complexity helps in the understanding of many events that occur in cellular membranes, that exhibit a wide variety of components, including lipids of different subfamilies (e.g., phospholipids, sphingolipids, sterols…), in addition to proteins and sugars. The capacity of lipids to segregate by themselves into different phases at the nanoscale (nanodomains) is an intriguing feature that is yet to be fully characterized in vivo due to the proposed transient nature of these domains in living systems. Model lipid membranes, instead, have the advantage of (usually) greater phase stability, together with the possibility of fully controlling the system lipid composition. Atomic force microscopy (AFM) is a powerful tool to detect the presence of meso- and nanodomains in a lipid membrane. It also allows the direct quantification of nanomechanical resistance in each phase present. In this review, we explore the main kinds of lipid assemblies used as model membranes and describe AFM experiments on model membranes. In addition, we discuss how these assemblies have extended our knowledge of membrane biophysics over the last two decades, particularly in issues related to the variability of different model membranes and the impact of supports/cytoskeleton on lipid behavior, such as segregated domain size or bilayer leaflet uncoupling.

Sign in / Sign up

Export Citation Format

Share Document