Lipid bilayer assembly at a gold nanocavity array

Jose, Bincy; Mallon, Colm T.; Forster, Robert J.; Blackledge, Chuck; Keyes, Tia E.

doi:10.1039/c1cc15709d

Cited by 17 publications

(25 citation statements)

References 29 publications

(31 reference statements)

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“…Because this process, also cell adhesion to a matrix as well as initiation of signaling all depend on cell surface binding, tailoring a substratum (mono- or bilayers) or liposomes, also termed nanoparticles, accordingly affords access to respective platforms for the next steps of testing, that is to build models for levels 5 and 6 of affinity regulation. Natural or synthetic glycolipids, together with cholesterol and glycerophosphatides, can be chosen to mimic membrane properties, even at array format [ 137 ], and this increasingly so in an iterative series. Self-assembling amphiphilic Janus dendrimers are another starting set for programmable vesicles of a size of choice [ 138 , 139 ].…”

Section: From Glycoclusters To Artificial Cell Surfacesmentioning

confidence: 99%

Lectins: Getting Familiar with Translators of the Sugar Code

et al. 2015

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The view on the significance of the presence of glycans in glycoconjugates is undergoing a paradigmatic change. Initially mostly considered to be rather inert and passive, the concept of the sugar code identifies glycans as highly versatile platform to store information. Their chemical properties endow carbohydrates to form oligomers with unsurpassed structural variability. Owing to their capacity to engage in hydrogen (and coordination) bonding and C-H/π-interactions these “code words” can be “read” (in Latin, legere) by specific receptors. A distinct class of carbohydrate-binding proteins are the lectins. More than a dozen protein folds have developed carbohydrate-binding capacity in vertebrates. Taking galectins as an example, distinct expression patterns are traced. The availability of labeled endogenous lectins facilitates monitoring of tissue reactivity, extending the scope of lectin histochemistry beyond that which traditionally involved plant lectins. Presentation of glycan and its cognate lectin can be orchestrated, making a glycan-based effector pathway in growth control of tumor and activated T cells possible. In order to unravel the structural basis of lectin specificity for particular glycoconjugates mimetics of branched glycans and programmable models of cell surfaces are being developed by strategic combination of lectin research with synthetic and supramolecular chemistry.

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Section: From Glycoclusters To Artificial Cell Surfacesmentioning

confidence: 99%

Lectins: Getting Familiar with Translators of the Sugar Code

et al. 2015

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“…Of note, galectins are present as a net work in vivo, with the possibility for functional competi tion [7,70]. Moving on to a model bilayer [71] and adding cholesterol will help increase the level of biorelevance. However, the steroid had been reported to reduce glycan accessibility by tilting the sugar chain of glycosphin golipids toward the membrane phase and to form a com positional asymmetry with GM1 [ 72 74].…”

Section: Discussionmentioning

confidence: 99%

X-ray reflectivity and grazing incidence diffraction studies of interaction between human adhesion/growth-regulatory galectin-1 and DPPE—GM1 lipid monolayer at an air/water interface

Majewski

André

Jones

et al. 2015

Biochemistry Moscow

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The specific interaction of ganglioside GM1 with the homodimeric (prototype) endogenous lectin galectin-1 triggers growth regulation in tumor and activated effector T cells. This proven biorelevance directed interest to studying association of the lectin to a model surface, i.e. a 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine/ganglioside GM1 (80 : 20 mol%) monolayer, at a bioeffective concentration. Surface expansion by the lectin insertion was detected at a surface pressure of 20 mN/m. On combining the methods of grazing incidence X-ray diffraction and X-ray reflectivity, a transient decrease in lipid-ordered phase of the monolayer was observed. The measured electron density distribution indicated that galectin-1 is oriented with its long axis in the surface plane, ideal for cis-crosslinking. The data reveal a conspicuous difference to the way the pentameric lectin part of the cholera toxin, another GM1-specific lectin, is bound to the monolayer. They also encourage further efforts to monitor effects of structurally different members of the galectin family such as the functionally antagonistic chimera-type galectin-3.

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“…The quality and uniformity of the microcavity array was confirmed by scanning electron microscopy as reported previously. 26,36 The microcavity array was sonicated for 15 minutes with the PBS buffer before the DOPC bilayer by lipid bilayer/vesicle fusion deposition as described above. The suspension and homogeneity of the bilayer film across the array was confirmed by confocal microscopy.…”

Section: Microcavity Arrays Supported Lipid Bilayersmentioning

confidence: 99%

“…The suspension and homogeneity of the bilayer film across the array was confirmed by confocal microscopy. 26,36 The aqueous filled lipid bilayer coated gold cavity array was placed inside glass cell containing PBS buffer along with the reference and auxiliary electrodes and electrochemical impedance spectroscopy was measured as described below.…”

Section: Microcavity Arrays Supported Lipid Bilayersmentioning

confidence: 99%

“…22,30,35 The lipid diffusivity studies are supported by electrochemical impedance measurements to investigate changes to the permeability of the membrane. 26,36 Electrochemical impedance spectroscopy (EIS) is used to measure the complex impedance properties of a material and has been widely used to study interfacial interactions, such as antigen-antibody interaction, and cancer cell capture as well as for evaluation of biomembranes. 27,[37][38][39] EIS was implemented here at gold microcavity array substrates analogous in structure to the optically transparent PDMS arrays used for FCS.…”

Section: Introductionmentioning

confidence: 99%

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Dynamic studies of the interaction of a pH responsive, amphiphilic polymer with a DOPC lipid membrane

et al. 2017

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Deeper understanding of the molecular interactions between polymeric materials and the lipid membrane is important across a range of applications from permeation for drug delivery to encapsulation for immuno-evasion. Using highly fluidic microcavity supported lipid bilayers, we studied the interactions between amphiphilic polymer PP50 and a DOPC lipid bilayer. As the PP50 polymer is pH responsive the studies were carried out at pH 6.5, 7.05 and 7.5, corresponding to fully, partly protonated (pH = pK = 7.05) and fully ionized states of the polymer, respectively. Fluorescence correlation spectroscopy (FCS) using both labelled lipid and polymer revealed the PP50 associates with the bilayer interface across all pHs where its diffusion along the interface is impeded. Both FCS and electrochemical impedance spectroscopy (EIS) data indicate that the PP50 does not penetrate fully into the bilayer core but rather forms a layer at the bilayer aqueous interface reflected in increased resistance and decreased capacitance of the bilayer on PP50 binding. The extent of these effects and the dynamics of binding are influenced by pH, increasing with decreasing pH. These experimental trends concurred with coarse grained Monte Carlo simulations of polymer-bilayer interactions wherein a model hydrophilic polymer backbone grafted with side chains of varying hydrophobicity, to mimic the effect of varying pH, was simulated based on the bond fluctuation model with explicit solvent. Simulation results showed that with increasing hydrophobicity, the polymer penetrated deeper into the contacting bilayer leaflet of the membrane suppressing, consistent with EIS data, solvent permeation and that a full insertion of the polymer into the bilayer core is not necessary for suppression of permeability.

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Lipid bilayer assembly at a gold nanocavity array

Abstract: The assembly of lipid bilayer membranes, using ultrasonic disruption of liposomes of L-α-Dimyristoyl phosphatidylcholine, across 820 nm diameter spherical cap gold cavity arrays is demonstrated.

Cited by 17 publications

References 29 publications

Lectins: Getting Familiar with Translators of the Sugar Code

Lectins: Getting Familiar with Translators of the Sugar Code

X-ray reflectivity and grazing incidence diffraction studies of interaction between human adhesion/growth-regulatory galectin-1 and DPPE—GM1 lipid monolayer at an air/water interface

Dynamic studies of the interaction of a pH responsive, amphiphilic polymer with a DOPC lipid membrane

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