Neutrons and model membranes: Moving towards complexity

Fragneto, Giovanna; Delhom, Robin; Joly, Loic; Scoppola, Ernesto

doi:10.1016/j.cocis.2018.10.003

Cited by 33 publications

(17 citation statements)

References 53 publications

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“…The technique allows the collection of structural information about the different layers of the membrane [54,55,56,57]. In particular, if the silicon support and the bulk water have been seen as bulk infinite layers, the silicon oxide layer, the water layer between the silicon oxide, and the membrane and the different hydrophilic and hydrophobic layers of the lipid membranes have been modelled as defined layers with a proper thickness, compactness, and mean composition (and therefore contrast).…”

Section: Methodsmentioning

confidence: 99%

Mucin Thin Layers: A Model for Mucus-Covered Tissues

Rondelli

Cola

Koutsioubas

et al. 2019

IJMS

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The fate of macromolecules of biological or pharmacological interest that enter the mucus barrier is a current field of investigation. Studies of the interaction between the main constituent of mucus, mucins, and molecules involved in topical transmucoidal drug or gene delivery is a prerequisite for nanomedicine design. We studied the interaction of mucin with the bio-inspired arginine-derived amphoteric polymer d,l-ARGO7 by applying complementary techniques. Small angle X-ray scattering in bulk unveiled the formation of hundreds of nanometer-sized clusters, phase separated from the mucin mesh. Quartz microbalance with dissipation and neutron reflectometry measurements on thin mucin layers deposited on silica supports highlighted the occurrence of polymer interaction with mucin on the molecular scale. Rinsing procedures on both experimental set ups showed that interaction induces alteration of the deposited hydrogel. We succeeded in building up a new significant model for epithelial tissues covered by mucus, obtaining the deposition of a mucin layer 20 Å thick on the top of a glycolipid enriched phospholipid single membrane, suitable to be investigated by neutron reflectometry. The model is applicable to unveil the cross structural details of mucus-covered epithelia in interaction with macromolecules within the Å discreteness.

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Section: Methodsmentioning

confidence: 99%

Mucin Thin Layers: A Model for Mucus-Covered Tissues

Rondelli

Cola

Koutsioubas

et al. 2019

IJMS

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“…However, these simple systems remain of interest for the investigation of collective fundamental physical properties as fluctuations [54,55], phase transitions [24,44] or structural dynamics [17,56]. In the last ten years, greater interest has been growing towards the investigation of more complex membranes composed by several constituents [57,58] or obtained from natural systems [59]. Of particular interest is the case of reconstituted Gram-negative bacterial membranes.…”

Section: Biological Membranesmentioning

confidence: 99%

Applications of neutron reflectometry in biology

Gerelli

2020

EPJ Web Conf.

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Over the last 10 years, neutron reflectometry (NR) has emerged as a powerful technique for the investigation of biologically relevant thin films. The great advantage of NR with respect to many other surface-sensitive techniques is its sub-nanometer resolution that enables structural characterizations at the molecular level. In the case of bio-relevant samples, NR is non-destructive and can be used to probe thin films at buried interfaces or enclosed in bulky sample environment equipment. Moreover, recent advances in biomolecular deutera-tion enabled new labeling strategies to highlight certain structural features and to resolve with better accuracy the location of chemically similar molecules within a thin film. In this chapter I will describe some applications of NR to bio-relevant samples and discuss some of the data analysis approaches available for biological thin films. In particular, examples on the structural characterization of biomembranes, protein films and protein-lipid interactions will be described.

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“…38 There are three different neutron scattering techniques commonly applied for different membrane models: (a) neutron diffraction for stacked bilayers (b) small angle neutron scattering for vesicles and bicelles, and (c) NR for single bilayers such as the POPC used in this work. 38,39 NR is a exible tool in structural biology due to its ability to discern the biomolecular architectures of lipid membranes and membrane-associated proteins without destroying the sample. It allows to mimic biological processes and to measure their structural responses.…”

Section: Neutron Reflectometrymentioning

confidence: 99%