The assembly of dialkyldimethylammonium bromide cationic lipids as vesicles or monolayers in presence of poly(ethylene glycol)

Adati, Renata Danielle; Feitosa, Eloi

doi:10.1016/j.tca.2015.05.022

Cited by 6 publications

(4 citation statements)

References 18 publications

(37 reference statements)

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“…Furthermore, DHDAB monolayers must be considered as being metastable, due to the solubility of the surfactant leading to a small loss of material into the subphase during compression (Kuo and Chang, 2015). Although both DPPG and DHDAB were in the gel phase at ambient temperature (Adati and Feitosa, 2015;Schmid et al, 2018) the differences in their monolayer compressibility behavior indicates that a mixing gap may be expected somewhere in the binary phase diagram (Sackmann and Demus, 1973), which needed to be taken into account when assessing their miscibility.…”

Section: Discussionmentioning

confidence: 99%

Enhanced chain packing achieved via putative headgroup ion-triplet formation in binary anionic lipid/cationic surfactant mixed monolayers

Wölk

Hause

Gutowski

et al. 2019

Chemistry and Physics of Lipids

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Lipid/surfactant miscibility was investigated in monolayers composed of binary mixtures of dipalmitoylphosphatidylglycerol (DPPG) and dihexadecyl dimethylammonium bromide (DHDAB). Langmuir monolayers formed from biomimetic DPPG/DHDAB mixtures based on the anionic:cationic lipid ratios observed in the bacterium Staphylococcus aureus (7:3 and 1:1) were examined alongside those of the pure amphiphiles and a surfactant rich 3:7 mixture. Using a combination of GIXD, TRXF and IRRAS, DPPG/DHDAB 1:1 monolayers were found to form a more stabilised condensed phase compared to pure DPPG, which was composed entirely of electrostatically neutral ion pairs, analogous to the so-called catanionic amphiphiles spontaneously formed by single-chain surfactants with opposing headgroup charges. Despite the lack of lateral charge repulsion the ion paired phase of DPPG/DHDAB exhibited slightly looser chain packing that was observed for DPPG indicating a significant steric effect on packing geometry caused by ion pair formation. Surprisingly, the 7:3 mixture of DPPG/DHDAB formed an completely condensed phase, with no isotherm transitions, in which the chain packing was significantly closer than was found for either DPPG or the totally ion paired monolayer. It is postulated that this mixture forms a distinct DPPG/DHDAB/DPPG ion triplet phase in which the overall negative charge is delocalised across the headgroups. Vesicles composed from the 7:3 mixture formed highly stable dispersions with an increased gel to liquid crystalline phase transition temperature with respect to its pure components. Increasing the proportion of DHDAB above 50 mol% led to demixing between the condensed ion paired phase and the more fluid surfactant, as was clearly observed in epifluorescence images taken of the surface films.

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Section: Discussionmentioning

confidence: 99%

Enhanced chain packing achieved via putative headgroup ion-triplet formation in binary anionic lipid/cationic surfactant mixed monolayers

Wölk

Hause

Gutowski

et al. 2019

Chemistry and Physics of Lipids

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“…Then, after 10 min the film compression started at a barrier speed of 10 mm min À1 . The surface pressure was obtained by the Wilhelmy plate method, as described before (Adati & Feitosa, 2015).…”

Section: Surface Film Balance Measurementsmentioning

confidence: 99%

Lipid exchanges between dioctadecyldimethylammonium bromide monolayer and vesicles in the subphase

Feitosa

Adati

Constantino

et al. 2021

J Surfact & Detergents

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Studies on the interaction of lipid monolayer with bilayer structures, such as vesicles, are relatively scarce in the literature. In order to ascertain whether these structures interact for cationic dioctadecyldimethylammonium bromide (DODAB) monolayers at the aqueous surfaces of 0, 0.05, and 0.5 mmol L À1 DODAB vesicle dispersions, differential scanning calorimetry (DSC) and surface film balance experiments were carried out. DSC results confirmed the presence of unilamellar vesicles in the subphase, while changes in the monolayer surface pressure-area per molecule (π-A) isotherm profile yielded by the presence of DODAB vesicle in the subphase revealed monolayer-vesicle interactions as a result of monomer exchanges between the monolayer and the vesicles with stronger effects at the higher vesicle concentration investigated.

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“…To avoid the interaction with the innate immune cells, nanoparticles are coated with a bio-polymer, such as PEG, that keeps them from being recognized and cleared by the mononuclear phagocyte system. 6 PEG functionalization is used in a wide range of nanomedical applications due to its flexible structure, non-reactivity, low toxicity 103 , 104 and solubility in water 104 – 107 and polar and nonpolar solvents 51 , 105 such as tetrahydrofuran, chloroform, dimethylsulfoxide 105 or methanol. 105 , 106 PEG is a hydrophilic polymer 106 – 111 with terminal hydroxyl groups 106 that covalently attach to the nanoparticles’ surface and form a protective shell, which inhibits the binding of serum proteins to the liposome, 112 increasing liposome circulation time, 49 , 109 preventing particle aggregation and protecting the liposomes from opsonization and the mononuclear phagocyte system.…”

Section: Functionalization and Applications Of Nanoparticles In Chemomentioning

confidence: 99%

The new era of nanotechnology, an alternative to change cancer treatment

Jurj

Braicu

Pop

et al. 2017

DDDT

147

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In the last few years, nanostructures have gained considerable interest for the safe delivery of therapeutic agents. Several therapeutic approaches have been reported, such as molecular diagnosis, disease detection, nanoscale immunotherapy and anticancer drug delivery that could be integrated into clinical use. The current paper aims to highlight the background that supports the use of nanoparticles conjugated with different types of therapeutic agents, applicable in targeted therapy and cancer research, with a special emphasis on hematological malignancies. A particular key point is the functional characterization of nonviral delivery systems, such as gold nanoparticles, liposomes and dendrimers. The paper also presents relevant published data related to microRNA and RNA interference delivery using nanoparticles in cancer therapy.

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The assembly of dialkyldimethylammonium bromide cationic lipids as vesicles or monolayers in presence of poly(ethylene glycol)

Abstract: 1: Gynecologic oncologists as benign gynecologic surgeons

Cited by 6 publications

References 18 publications

Enhanced chain packing achieved via putative headgroup ion-triplet formation in binary anionic lipid/cationic surfactant mixed monolayers

Enhanced chain packing achieved via putative headgroup ion-triplet formation in binary anionic lipid/cationic surfactant mixed monolayers

Lipid exchanges between dioctadecyldimethylammonium bromide monolayer and vesicles in the subphase

The new era of nanotechnology, an alternative to change cancer treatment

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