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Pott, Tanja; Colin, Annie; Navailles, Laurence; Roux, D.

doi:10.1023/a:1022139115433

Cited by 18 publications

(21 citation statements)

References 7 publications

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“…Structural studies of both the cationic and zwitterionic DNA lipoplexes have been reported over the past number of years. [4][5][6][13][14][15][16][17][18][19][20][21] However, here we show for the first time that, in addition to the enhanced divalent cation binding, 17 this complex is capable of arranging DNA into higher orders of local organization.The complex is prepared by mixing DNA (calf thymus, purified by a method described before 18 ), unilamellar liposomes of DPPC, prepared by bath sonication at 50°C, and calcium from concentrated stocks in the wide part of a 1 mm X-ray capillary. The complex was allowed to form for 1 h before being centrifuged to the end of the capillary and equilibrated by a cycle of heating and cooling, above and below the melt transition temperature of the lipid over a number of days.…”

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confidence: 91%

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confidence: 91%

“…[9][10][11][12][13][14] Complexes formed by neutral lipids in the absence of the divalent cation have also been described. 15,16 The divalent cation-lipid complexes are entirely noncytotoxic and thereby have a remarkable status among the candidate systems in that the binding is highly tunable. They have been studied less, possibly due to the erroneous assumption that the interaction between divalent cations and zwitterionic lipids is weak.…”

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Observation of a Rectangular Columnar Phase in a DNA−Calcium−Zwitterionic Lipid Complex

McManus

Rädler²,

Dawson³

2004

J. Am. Chem. Soc.

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Complexes composed of DNA and cationic lipids have been studied in detail in recent years, mainly due to their potential to deliver DNA to cells in gene therapy. 1 It has been recognized that different structures can be prepared, based on these compositions and lipid chemistry. In this communication, we give the first example of a higher-order arrangement of DNA within an entirely noncytotoxic complex.This opens the pathway to explore the consequences of such ordering on the issue of delivery and other arenas where DNA arrays may have biological significance. We believe such nontoxic ordered arrays of DNA may in the future represent novel components of structural and functional significance at the interface of the "synthetic biology" endeavor. 2 Until now most studies on these synthetic systems have been done with the focus of creating artificial devices for gene delivery. In these cases, some researchers have screened large numbers of different lipid-DNA formulations to identify successful candidates in vitro. 3 Others, however, have tried to understand the complexes on a more fundamental level, studying structure, phase behavior, and other physical characteristics, in the hope that this would ultimately enable a "design"-based approach to delivery, 4-8 but no systematic understanding has emerged.However, we consider that there emerges a general role for the engineering of ordered arrays of DNA that can protect the DNA in a biological environment but which is easily manipulated to provide compact readable and addressable devices. Such complexes typically cannot be based on direct electrostatic interaction between cationic lipids and DNA, as these are quite cytotoxic and the degree of binding is ill-controlled after initial preparation. However, complexes composed entirely of natural, zwitterionic lipid can complex with DNA when the interaction is mediated by a divalent cation. [9][10][11][12][13][14] Complexes formed by neutral lipids in the absence of the divalent cation have also been described. 15,16 The divalent cation-lipid complexes are entirely noncytotoxic and thereby have a remarkable status among the candidate systems in that the binding is highly tunable. They have been studied less, possibly due to the erroneous assumption that the interaction between divalent cations and zwitterionic lipids is weak. We have shown previously that the complex forms over a number of calcium concentrations. Structural studies of both the cationic and zwitterionic DNA lipoplexes have been reported over the past number of years. [4][5][6][13][14][15][16][17][18][19][20][21] However, here we show for the first time that, in addition to the enhanced divalent cation binding, 17 this complex is capable of arranging DNA into higher orders of local organization.The complex is prepared by mixing DNA (calf thymus, purified by a method described before 18 ), unilamellar liposomes of DPPC, prepared by bath sonication at 50°C, and calcium from concentrated stocks in the wide part of a 1 mm X-ray capillary. The complex was allowed t...

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confidence: 91%

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confidence: 91%

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confidence: 99%

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Observation of a Rectangular Columnar Phase in a DNA−Calcium−Zwitterionic Lipid Complex

McManus

Rädler²,

Dawson³

2004

J. Am. Chem. Soc.

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“…A more promising strategy uses neutral lipids. [11] Possible applications of DNA/lipid phases to nano-structuring have also been considered. [12] We will not describe in detail the experimental techniques used to study doped phases because these techniques are essentially those already used in the field of lyotropic liquid crystals, namely phase diagram identification, polarized-light microscopy, smallangle X-ray scattering, and rheology or in the field of nanoparticles, namely electron microscopy and IR-Vis-UV spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Lamellar L_α Mesophases Doped with Inorganic Nanoparticles

Constantin¹

2014

ChemPhysChem

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A flourishing research activity, bringing together chemistry, physics and materials science, aims to develop nanostructured hybrid systems composed of nanoparticles with interesting properties (optical, magnetic, catalytic, etc.) IntroductionElaborating and investigating hybrid materials by inserting inorganic (metallic or mineral) nanoparticles into liquid crystal phases has recently become the focus of intense worldwide research, motivated by the perspective of industrial applications as diverse as display technology, drug delivery, or information storage. Indeed, such hybrid materials may combine the typical electronic properties of inorganic materials (magnetism, lightabsorption, electrical conductivity) with the characteristic properties of liquid-crystals (fluidity, anisotropy, processability, spatial confinement). From a more fundamental point of view, these hybrid materials can also help addressing new issues about novel mesophases and about how the lamellar mesophase is affected by the nanometric inclusions and how the latter experience new membrane-mediated interactions. Moreover, such organic-inorganic lamellar phases provide good model systems to mimic peptidic inclusions in biological membranes. Both these applied and fundamental considerations drive the fast expansion of this field, making this Minireview timely. The scope of this Minireview, however, has been restricted in order to keep it to a reasonable size. For example, we will not address here the cases of either large particles (with all dimensions larger than about 100 nm) or thermotropic liquid crystals. The latter have been the subject of recent reviews. [1] Moreover, although hybrid materials obtained by inserting mineral or metallic nanoparticles into the lamellar phase of blockcopolymers have recently raised much attention, this large research field will not be covered as fairly recent reviews have been dedicated to this topic.[1e, 2] Also, we will not describe the insertion of polymer coils into lamellar phases. Moreover, we will not review here any work about the DNA-surfactant complexes that have raised much interest for applications in transfection since the mid-1990s. [3] We only consider bulk materials and thus we omit thin films, Langmuir monolayers and layer-by-layer assemblies. We also do not consider here the hybrid lamellar phases of organometallic lyotropic and thermotropic compounds that display homogeneous inorganic sublayers rather than individual nanoparticles. [4] In spite of the recent reports of liquidcrystalline properties of graphene and graphene oxide suspensions [5] and of the insertion of graphene in thermotropic liquid crystals, [6] we are not yet aware of any work describing lyotropic lamellar phases doped with such carbon-based nanosheets. Most importantly, we do not review here the fastexpanding field of the synthesis of nanoparticles within liquidcrystalline templates. [7] In recent years, the study of nanoparticles inserted within lyotropic mesophases has made remarkable progress. This development was ...

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“…Therefore, studies of lipid self‐organization and factors influencing this process generate ongoing interest. Among these factors are the presence of charged proteins or polymers . Small polyanions have some advantage in this respect, because of their simple structure; furthermore, lipid‐polyanion systems have potential as vesicles for drug delivery .…”

Section: Introductionmentioning

confidence: 99%

Interaction of polyacrylic acid with lipid bilayers: effect of polymer mass

Munavirov

Гнездилов

Rudakova

et al. 2013

Magnetic Reson in Chemistry

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Polyanion-coated lipid vesicles are proposed to have an appreciable potential for drug delivery because of their ability to control the permeability of lipid bilayers by environmental parameters such as pH and temperature. However, details of the interaction of this class of polymers with lipids and their mechanisms of induced permeability are still being debated. In this work, we applied (1)H NOESY to study details of the interaction of polyacrylic acid (PAA) fractions of molecular weights 5 and 240 kDa with dimyristoylphosphatidylcholine vesicles. We showed that PAA of two different molecular masses modifies lipid bilayers increasing disorder and probability of close contact between polar and hydrophobic groups. PAA molecules adsorb near the interface of lipid bilayers but do not penetrate into the hydrophobic core of the bilayer and, thus, cannot participate in formation of transbilayer channels, proposed in earlier works. Increasing the molecular mass of PAA from 5 kDa to 240 kDa does not change the effect of PAA on the bilayer, although PAA240 forms a more compact structure (either intra-molecular or inter-molecular) and interacts more strongly with interface lipid protons.

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Untitled

Cited by 18 publications

References 7 publications

Observation of a Rectangular Columnar Phase in a DNA−Calcium−Zwitterionic Lipid Complex

Observation of a Rectangular Columnar Phase in a DNA−Calcium−Zwitterionic Lipid Complex

Lamellar L_α Mesophases Doped with Inorganic Nanoparticles

Interaction of polyacrylic acid with lipid bilayers: effect of polymer mass

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Untitled

Cited by 18 publications

References 7 publications

Observation of a Rectangular Columnar Phase in a DNA−Calcium−Zwitterionic Lipid Complex

Observation of a Rectangular Columnar Phase in a DNA−Calcium−Zwitterionic Lipid Complex

Lamellar Lα Mesophases Doped with Inorganic Nanoparticles

Interaction of polyacrylic acid with lipid bilayers: effect of polymer mass

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Lamellar L_α Mesophases Doped with Inorganic Nanoparticles