Compound Complex Formation in Phospholipid Membranes Induced by a Nonionic Surfactant of the Oligo(ethylene oxide)–Alkyl Ether Type: A Comparative DSC and FTIR Study

Mädler, Burkhard; Binder, Hans; Klose, G.

doi:10.1006/jcis.1998.5416

Cited by 26 publications

(34 citation statements)

References 57 publications

(35 reference statements)

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“…The thermodynamic data could be interpreted in terms of a strong correlation between mixing properties and the hydration of the headgroups, the water exposure of the hydrophobic core, and packing effects of the hydrocarbon chains. Similar results were obtained by means of differential scanning calorimetry (DSC) in combination with infrared (IR) spectroscopy (11). Unfortunately, these investigations are restricted to excess water conditions enabling only indirect conclusions about local hydration properties.…”

Section: Introductionsupporting

confidence: 71%

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Hydration and Lyotropic Melting of Amphiphilic Molecules: A Thermodynamic Study Using Humidity Titration Calorimetry

Binder

Kohlstrunk

Heerklotz

1999

Journal of Colloid and Interface Science

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Section: Introductionsupporting

confidence: 71%

“…9 and Eqs. [10] and [11]). The negative slope of ϪT ⅐ ⌬S s3b indicates that hydration is entropically driven for the amphiphiles investigated.…”

Section: Enthalpy and Entropy Of Dehydrationmentioning

confidence: 94%

Hydration and Lyotropic Melting of Amphiphilic Molecules: A Thermodynamic Study Using Humidity Titration Calorimetry

Binder

Kohlstrunk

Heerklotz

1999

Journal of Colloid and Interface Science

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“…We expected monocaprylate's site of action to be the cell membrane, as monoglycerides are generally proposed to act as nonionic surfactants that interact with and disrupt membranes (4,6,39). In theory, integration of monocaprylate in the membrane would lower the membrane's melting temperature (19,28) and thereby increase its fluidity and permeability (9). We therefore hypothesized that monocaprylate integrates into the membrane and destabilizes it, which results in membrane permeabilization.…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial Mechanism of Monocaprylate

Hyldgaard

Sutherland

Sundh

et al. 2012

Appl Environ Microbiol

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ABSTRACTMonoglyceride esters of fatty acids occur naturally and encompass a broad spectrum of antimicrobial activity. Monocaprylate is generally regarded as safe (GRAS) and can function both as an emulsifier and as a preservative in food. However, knowledge about its mode of action is lacking. The aim of this study was therefore to elucidate the mechanism behind monocaprylate's antimicrobial effect. The cause of cell death inEscherichia coli,Staphylococcus xylosus, andZygosaccharomyces bailiiwas investigated by examining monocaprylate's effect on cell structure, membrane integrity, and its interaction with model membranes. Changes in cell structure were visible by atomic force microscopy (AFM), and propidium iodide staining showed membrane disruption, indicating the membrane as a site of action. This indication was confirmed by measuring calcein leakage from membrane vesicles exposed to monocaprylate. AFM imaging of supported lipid bilayers visualized the integration of monocaprylate into the liquid disordered, and not the solid ordered, phase of the membrane. The integration of monocaprylate was confirmed by quartz crystal microbalance measurements, showing an abrupt increase in mass and hydration of the membrane after exposure to monocaprylate above a threshold concentration. We hypothesize that monocaprylate destabilizes membranes by increasing membrane fluidity and the number of phase boundary defects. The sensitivity of cells to monocaprylate will therefore depend on the lipid composition, fluidity, and curvature of the membrane.

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“…3f). The FTIR spectra of similar surfactant molecules in both solid and LC phase have been recorded, and the assignments of the peaks in the δ-CH 2 and ν-CO regions have been made (24,25). However, the δ-CH 2 and ν-CO regions of the spectra become highly broad and hard to convolute when the AgNO 3 /surfactant ratio is between 0.5 and 1.5 (Figs.…”

Section: Resultsmentioning

confidence: 99%

Silver Nitrate/Oligo(ethylene Oxide) Surfactant/Mesoporous Silica Nanocomposite Films and Monoliths

Samarskaya

Dag

2001

Journal of Colloid and Interface Science

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A lyotropic, liquid crystalline (LC) phase of a silver nitrate/ oligo(ethylene oxide), water, and acid mixture was used for onepot synthesis of mesoporous silica materials in which Ag + ions are uniformly distributed. We established that the AgNO 3 -to-surfactant mole ratio is very important in a 50 wt% surfactant/water system to preserve the hexagonal LC phase before and after the addition of the silica source. Below a 0.6 AgNO 3 -to-surfactant mole ratio, the mixture is liquid crystalline and serves as a template for silica polymerization. However, between 0.6 and 0.8 AgNO 3 -to-surfactant mole ratios, one must control the composition of the mixture during the polymerization processes. Above a 0.8 mole ratio, Ag + ions undergo phase separation from the reaction mixture by complexing with the surfactant molecules. The resulting silica materials obtained from AgNO 3 /surfactant ratios above 0.8 have anisotropy but without a hexagonal mesophase. Here, we establish a AgNO 3 concentration range in which the LC phase is preserved to template the synthesis of mesoporous silica, and we discuss the structural behavior of the mixtures at AgNO 3 /surfactant mole ratios of 0.00-2.00, using POM, PXRD, FTIR, and UV-Vis absorption spectroscopy. C 2001 Academic Press

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Compound Complex Formation in Phospholipid Membranes Induced by a Nonionic Surfactant of the Oligo(ethylene oxide)–Alkyl Ether Type: A Comparative DSC and FTIR Study

Cited by 26 publications

References 57 publications

Hydration and Lyotropic Melting of Amphiphilic Molecules: A Thermodynamic Study Using Humidity Titration Calorimetry

Hydration and Lyotropic Melting of Amphiphilic Molecules: A Thermodynamic Study Using Humidity Titration Calorimetry

Antimicrobial Mechanism of Monocaprylate

Silver Nitrate/Oligo(ethylene Oxide) Surfactant/Mesoporous Silica Nanocomposite Films and Monoliths

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