Structure and Conformational Dynamics of DMPC/Dicationic Surfactant and DMPC/Dicationic Surfactant/DNA Systems

Abstract

Amphiphilic dicationic surfactants, known as gemini surfactants, are currently studied for gene delivery purposes. The gemini surfactant molecule is composed of two hydrophilic “head” groups attached to hydrophobic chains and connected via molecular linker between them. The influence of different concentrations of 1,5-bis (1-imidazolilo-3- decyloxymethyl) pentane chloride (gemini surfactant) on the thermotropic phase behaviour of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayers with and without the presence of DNA was investigated using Fourier transformed infrared (FTIR) and circular dichroism (CD) spectroscopies, small angle scattering of synchrotron radiation and differential scanning calorimetry. With increasing concentration of surfactant in DMPC/DNA systems, a disappearance of pretransition and a decrease in the main phase transition enthalpy and temperature were observed. The increasing intensity of diffraction peaks as a function of surfactant concentration also clearly shows the ability of the surfactant to promote the organisation of lipid bilayers in the multilayer lamellar phase.

Interaction between a cationic bolaamphiphile and DNA: The route towards nanovectors for oligonucleotide antimicrobials

“…It is quite evident how the intensity reaches zero just above the isoelectric point. The same experimental trend has been evidenced for the condensation of different types of DNA by traditional [34] and gemini cationic surfactants [35,36].…”

“…By observing the absorption spectra in Figure S10, authors for classic cationic surfactants [37], gemini surfactants [35,36], and bolaamphiphiles [38,39]. This can be an advantage compared to certain cationic species which necessitate higher Z+/-values to saturate the DNA: for example, other authors reported Z+/-= 4 for poly(ethylenimine) [40], Z+/-= 10 for TTAB and Z+/-= 30 for DTAB [34], which necessitate higher amounts of typically cytotoxic compounds to reach full condensation.…”

Recent progress in gene therapy to deliver nucleic acids with multivalent cationic vectors

“…The electrostatic interaction in the complex may be also studied by conductivity [91] or, with less accuracy, by gel electrophoresis [92,93]. Fluorescence intercalation assays with ethidium bromide or GelRed, and circular dichroism have been used for monitoring the DNA compaction process by the gene vector together with the nature of the GV-NA interaction [77,[94][95][96]. The size and morphology of the complexes are studied by static (SLS) or dynamic (DLS) light scattering and electron microscopy (EM, TEM, and cryo-TEM) methods [60,93,95,97].…”

“…The fluidity of the gene vector (preferently when they are lipids) has been studied by means of fluorescence anisotropy [93]. Calorimetric methods, as DSC and ITC, have permitted to evaluate the energetics of the compaction process [91,95,96]. Topological aspects of the condensed complexes have been analyzed by scanning microscopy, such as AFM [91,98].…”

Phase Transitions and Supramolecular Organization in the Water / Ethoxylated Izononilfenol : Polyglyceryl-3 Methylglucose Distearate / Vaseline Oil System

“…Самоорганизация приводит к образованию мицелл, липосом и везикул, лиотропных жидкокристаллических фаз и микро-эмульсий. Эти самоорганизующиеся структуры используются для солюбилизации и транспорта полезных веществ [1,2,3] в качестве темплатов для синтеза наночастиц [4,5], моделей биологических мембран [6,7], реакционных сред [8,9] и это только некоторые из их применений.…”