Internal Nanostructures Research Articles

Transition Metal Ion-Mediated Tyrosine-Based Short-Peptide Amphiphile Nanostructures Inhibit Bacterial Growth.

We report the design and synthesis of a biocompatible small-peptide-based compound for the controlled and targeted delivery of encapsulated bioactive metal ions through transformation of the internal nanostructures of its complexes. A tyrosine-based short-peptide amphiphile (sPA) was synthesized and observed to self-assemble into β-sheet-like secondary structures. The self-assembly of the designed sPA was modulated by application of different bioactive transition-metal ions, as was confirmed by spectroscopic and microscopic techniques. These bioactive metal-ion-conjugated sPA hybrid structures were further used to develop antibacterial materials. As a result of the excellent antibacterial activity of zinc ions the growth of clinically relevant bacteria such as Escherichia coli was inhibited in the presence of zinc⋅sPA conjugate. Bacterial testing demonstrated that, due to high biocompatibility with bacterial cells, the designed sPA acted as a metal ion delivery agent and might therefore show great potential in locally addressing bacterial infections.

Cisplatin Encapsulation Generates Morphologically Different Multicompartments in the Internal Nanostructures of Nonlamellar Liquid-Crystalline Self-Assemblies.

Cisplatin ( cis-diamminedichloroplatinum(II)) is among the most potent cytotoxic agents used in cancer chemotherapy. The encapsulation of cisplatin in lipid-based drug carriers has been challenging owing to its low solubility in both aqueous and lipid phases. Here, we investigated cisplatin encapsulation in nonlamellar liquid-crystalline (LC) nanodispersions formed from a ternary mixture of phytantriol (PHYT), vitamin E (Vit E), and an anionic phospholipid [either phosphatidylglycerol (DSPG) or phosphatidylserine (DPPS)]. We show an increase in cisplatin encapsulation efficiency (EE) in nanodispersions containing 1.5-4 wt % phospholipid. The EE was highest in DPPS-containing nanodispersions (53-98%) compared to DSPG-containing counterparts (25-40%) under similar experimental conditions. Through structural and morphological characterizations involving synchrotron small-angle X-ray scattering and cryogenic transmission electron microscopy, we further show that varying the phospholipid content of cisplatin-free nanodispersions triggers an internal phase transition from a neat hexagonal (H2) phase to a biphasic phase (internal H2 phase coexisting with the lamellar (Lα) phase). However, cisplatin encapsulation in both DPPS- and DSPG-containing nanodispersions generates the coexistence of morphologically different multicompartments in the internal nanostructures comprising vesicles as a core, enveloped by an inverted-type surface bicontinuous cubic Im3 m (primitive, QIIP) phase or H2 phase. We discuss the biophysical basis of these drug-induced morphological alterations and provide insights into the potential development of inverted-type LC nanodispersions for cisplatin delivery.

Controlling the nanostructure of epoxy resins: Reaction selectivity and stoichiometry

The internal topology of epoxy resins is, for the first time, shown not to be the determining factor for small molecule transport. Whilst epoxy resins comprise the matrix component of many high performance composites, coatings and adhesives, the nanostructure and transport properties of these materials are not well understood. Here, peakforce AFM imaging, in-situ FTIR cure analysis and nanochemical AFM-IR imaging are used to establish the effects of reaction selectivity and stoichiometry on the nanostructure of epoxy-phenolic resins based on bisphenol-A and diglycidyl ether of bisphenol-A. In the presence of excess epoxy, resins transition from exhibiting homogeneous internal nanostructures to the familiar nodular morphology characteristic of epoxies. This occurs as a result of lower reaction selectivity in the presence of increasing catalyst concentrations. Surprisingly however, chemically similar stoichiometric resins with a heterogeneous nanostructure display improved resistance to corrosion breakdown (ion transport) and lower water uptake than the homogeneous resins.

Structural absorption by barbule microstructures of super black bird of paradise feathers

Many studies have shown how pigments and internal nanostructures generate color in nature. External surface structures can also influence appearance, such as by causing multiple scattering of light (structural absorption) to produce a velvety, super black appearance. Here we show that feathers from five species of birds of paradise (Aves: Paradisaeidae) structurally absorb incident light to produce extremely low-reflectance, super black plumages. Directional reflectance of these feathers (0.05–0.31%) approaches that of man-made ultra-absorbent materials. SEM, nano-CT, and ray-tracing simulations show that super black feathers have titled arrays of highly modified barbules, which cause more multiple scattering, resulting in more structural absorption, than normal black feathers. Super black feathers have an extreme directional reflectance bias and appear darkest when viewed from the distal direction. We hypothesize that structurally absorbing, super black plumage evolved through sensory bias to enhance the perceived brilliance of adjacent color patches during courtship display.

Aripiprazole-loaded in Soft Lipidic Non-Lamellar Liquid Crystalline Nanostructures

Event Abstract Back to Event Aripiprazole-loaded in Soft Lipidic Non-Lamellar Liquid Crystalline Nanostructures Intan Diana Mat Azmi1* and Lai Y. Khen1 1 Putra Malaysia University, Malaysia Background Non-lamellar liquid crystalline (LC) nanostructures have recently received attention in application in drug delivery systems, due to their unique well-defined and tunable internal nanostructures. The rich polymorphism of LC nanostructures are considered as a key factor in improving loading efficiency of different types of poorly soluble therapeutic agents. This project is focused on developing Aripiprazole-loaded non-lamellar LC nanostructures, consisted of a binary mixture of soy phosphatidylcholine (SPC) and citric acid ester of monoglyceride (citrem). Aripiprazole is a psychotropic drug that used to treat schizophrenia and bipolar disorder, which showed poor aqueous solubility of less than 0.3 μg/ ml. It is utmost interest to see the potential of non-lamellar LC nanoparticles in improving the loading efficiency of Aripiprazole by entrapping the drugs into their well-order internal nanostructures. Methods The investigated drug-free and drug-loaded nanodispersions were prepared based on a lipid ratio of SPC:Citrem (1:1 wt/wt) at 5 wt% lipid concentration via high energy ultrasonication. The characterizations were done to determine the particle size, stability, morphology, encapsulation efficiency and the interaction between the drugs and the nanodispersions. Results The results show that Aripiprazole, at three different concentrations (0.1, 0.2, and 0.25 wt%), were successfully loaded into LC nanoparticles where the encapsulation efficiency was all above 92%. The particle size of LC nanoparticles produced was in the range of 154.1-183.4nm, with polydispersity index, PDI 0.103-0.172, and zeta potential of -26.0mV to -29.1mV. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) showed that there was a chemical interaction between Aripiprazole and LC nanoparticles, while Transmission Electron Microscopy (TEM) was used to see the morphology and overall size distribution of drug-free and drug-loaded nanodispersions. Conclusion This study suggests the potential use of non-lamellar LC nanodispersions as a promising nanocarrier for Aripiprazole delivery, which is expected to improve the pharmacokinetics and stability of this drug. Acknowledgements Authors would like to thank Universiti Putra Malaysia for the IPM grant. Keywords: Liquid crystalline nanostructures, aripiprazole, Drug delivery, Schizophrenia, Nanoparticle (NP) Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Poster Presentation Topic: Mental health Citation: Mat Azmi I and Khen LY (2019). Aripiprazole-loaded in Soft Lipidic Non-Lamellar Liquid Crystalline Nanostructures. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2018.63.00050 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Oct 2018; Published Online: 17 Jan 2019. * Correspondence: Dr. Intan Diana Mat Azmi, Putra Malaysia University, Seri Kembangan, Malaysia, intandiana@upm.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Intan Diana Mat Azmi Lai Y Khen Google Intan Diana Mat Azmi Lai Y Khen Google Scholar Intan Diana Mat Azmi Lai Y Khen PubMed Intan Diana Mat Azmi Lai Y Khen Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Injectable in situ forming gel based on lyotropic liquid crystal for persistent postoperative analgesia.

To address the issue of insufficient postoperative analgesia associated with short half-lives of local anesthetics after single injection, an in situ forming gel (ISFG) based on lyotropic liquid crystal was developed to deliver bupivacaine hydrochloride (BUP) for postoperative analgesia over three days. The results demonstrated that persistent analgesia effect in vivo was achieved with single injection of BUP-ISFG, and the plasma BUP concentration was found to be steadier compared to commercially available BUP injection. The BUP-ISFG possessed a lamellar-hexagonal-cubic phase transition with corresponding crystal change in 3D nanostructure during the in situ gelation. The relationship between crystal nanostructure and carrier function, might provide some insights to the design and clinical applications of the drug delivery systems based on lyotropic liquid crystal.

Nanostructured monolinolein miniemulsions as delivery systems: Role of the internal mesophase on cytotoxicity and cell internalization

Recent advances in nanoparticle systems for improved drug delivery display a great potential for the administration of active molecules. Here, lipid miniemulsions with various internal nanostructures were loaded with the chemotherapeutic agent Paclitaxel. The goal is to assess the impact of internal structures on their efficiency. Previously the structure, the stability and the physico-chemical properties of those carriers were characterized. Modalities of action were addressed by the evaluation of their effects on the tumor cells viability, their cellular uptake by flow cytometry and confocal microscopy detection of fluorescently labeled nanostructured miniemulsions. Nanostructured miniemulsions showed variations in the cell internalization process likely due to differences in the internal structure. All paclitaxel-loaded emulsions were active reservoirs from which Paclitaxel could be released, however bicontinuous cubosomes showed the best efficiency. Considering the fact that these delivery systems can offer a new life to bioactive compounds previously abandoned due to a low aqueous solubility, these data may represent an important step towards the development of new clinical therapeutic strategies against cancers.

Reactive Ni/Al Nanocomposites: Structural Characteristics and Activation Energy.

Stochastically structured Ni/Al reactive nanocomposites (RNCs) were prepared using short-term high-energy ball milling. Several milling times were utilized to prepare RNCs with differing internal nanostructures. These internal structures were quantitatively and statistically analyzed by use of serial focused ion beam sectioning coupled with 3D reconstruction techniques. The reaction kinetics were analyzed using the electrothermal explosion technique for each milling condition. It is shown that the effective activation energy (Eef) ranges from 79 to 137 kJ/mol and is directly related to the surface area contact between the reactants. Essentially, the reaction kinetics can be accurately controlled through mechanical processing techniques. Finally, the nature of the reaction is considered; the mechanistic effect of the reactive and three diffusive activation energies on the effective activation energy is examined.

Interface tuning and stabilization of monoglyceride mesophase dispersions: Food emulsifiers and mixtures efficiency

Several food surfactants were examined as possible efficient emulsifiers for liquid crystalline monolinolein-based particles and as alternative choices to the non-food-grade emulsifier conventionally used Pluronic® F127. We described a food emulsifiers’ toolbox, investigating their ability to emulsify mesophases (stabilization capacity, particle size, zeta potential) and their impact on internal nanostructures (from swelling to drastic modifications). Among the selected surfactants, sucrose stearate (S1670) was found to be the best candidate for replacing in a long term F127 as an efficient stabilizer of lipid particles. The emulsification performed by mixing F127 with S1670 or sodium caseinate (NaCas), and S1670/NaCas helped to discriminate their respective role in the particles and so their efficiency for the stabilization. In case of S1670 as co-emulsifier no strong structural modification was observed, while using F127 (25wt% NaCas) an unexpected hexagonal mesophase was highlighted in self-assemblies. The evolution of zeta potentials by varying the mesophase and the emulsifier also informed about the distribution of co-surfactants in the particles. We thus reported submicronic nanostructured systems (from 100 to 350nm) that were fully food-grade and possibly contained limonene, with a surface charge from −70 to −5mV.

Rational Design of Morphological Characteristics to Determine the Optimal Hierarchical Nanostructures in Heterogeneous Catalysis

AbstractThis work draws attention to the optimal hierarchical nanostructure morphology and the morphological characteristics that lead to a rational design of heterogeneous nanocatalysts, especially for reactions that exhibit sluggish kinetics. A simplified methanol oxidation on two types of hierarchical nanostructures, external and internal, is reported. A complex system of asymmetric geometries was simplified by mapping 3 D geometries into 2 D models by using a mass transport approach. The macropore size was the most comprehensive characteristic to evaluate the specific activity and current density of hierarchical nanostructures. The optimal current densities for both types of nanostructures were achieved in macropore size ranges of 3.2–4.5 and 1.9–3.2 μm, respectively. The optimal mass activity of the internal nanostructures was achieved in the porosity range of 40–50 %, whereas that of the external hierarchical nanostructures was achieved at high porosity values. In comparison to internal hierarchical nanostructures, external hierarchical nanostructures tend to be cost‐effective catalysts that have a high catalytic activity.

A structurally diverse library of safe-by-design citrem-phospholipid lamellar and non-lamellar liquid crystalline nano-assemblies

Non-lamellar liquid crystalline aqueous nanodispersions, known also as ISAsomes (internally self-assembled ‘somes’ or nanoparticles), are gaining increasing interest in drug solubilisation and bio-imaging, but they often exhibit poor hemocompatibility and induce cytotoxicity. This limits their applications in intravenous drug delivery and targeting. Using a binary mixture of citrem and soy phosphatidylcholine (SPC) at different weight ratios, we describe a library of colloidally stable aqueous and hemocompatible nanodispersions of diverse nanoarchitectures (internal self-assembled nanostructures). This engineered library is structurally stable in human plasma as well as being hemocompatible (non-hemolytic, and poor activator of the complement system). By varying citrem to lipid weight ratio, the nanodispersion susceptibility to macrophage uptake could also be modulated. Finally, the formation of nanodispersions comprising internally V2 (inverse bicontinuous cubic) and H2 (inverse hexagonal) nanoarchitectures was achieved without the use of an organic solvent, a secondary emulsifier, or high-energy input. The tunable binary citrem/SPC nanoplatform holds promise for future development of hemocompatible and immune-safe nanopharmaceuticals.

Mass transport and catalytic activity in hierarchical/non-hierarchical and internal/external nanostructures: A novel comparison using 3D simulation

The distinct organization of nanostructured materials influences several catalytic characteristics, like selectivity, sensitivity or catalytic efficiency. This paper studies the effect of geometrical configuration of nanostructured catalyst on mass transport and catalytic activity based on 3D simulations of hierarchical external, hierarchical internal, non-hierarchical external and non-hierarchical internal nanostructures. Generally, external nanostructures revealed higher utilization of catalytic surface than the internal nanostructures. Among the four investigated nanostructures, the mass transport in hierarchical external nanostructures was found to be the best; they even showed kinetic controlled regime for the species with low diffusion coefficient. In contrast, hierarchical internal nanostructures showed slightly less specific activity than non-hierarchical internal nanostructures because of higher total diffusional resistance and longer diffusional path. As a result, although hierarchical nanostructures possess large surface area, only the hierarchical external nanostructures provided an outstanding accessibility of active sites. The obtained results provide the tool for understanding the catalytic efficiency in complex nanostructure and phenomena that are technically difficult to measure.

Citrem modulates internal nanostructure of glyceryl monooleate dispersions and bypasses complement activation: Towards development of safe tunable intravenous lipid nanocarriers

Lyotropic non-lamellar liquid crystalline (LLC) aqueous nanodispersions hold a great promise in drug solubilization and delivery, but these nanosystems often induce severe hemolysis and complement activation, which limit their applications for safe intravenous administration. Here, we engineer and characterize LLC aqueous nanodispersions from a binary lipid mixture consisting of 2,3-dihydroxypropyl oleate (glyceryl monooleate) and medium-chain triglycerides with tunable internal nanostructures and improved hemocompatibility controlled by citrem as stabilizer. Citrem, in a concentration-dependent manner, modulates the internal nanostructure of LLC dispersions from a biphasic H2/L2 feature to a neat L2 phase, where the latter resembles “thread-like” swollen micelles. Citrem stabilization totally overcomes hemolysis and complement activation, thus realizing the potential of the engineered LLC aqueous nanodispersions for exploitation in intravenous delivery of drugs and contrast agents. From the Clinical EditorThe complement system often gets activated after intravenous injection of nano drug-carriers. This may result in detrimental systemic effects. The authors described in this article the use of citrem as a stabilizing agent and showed the ability of this agent to abolish complement activation. Hence, citrem may prove to be an important component of tunable LLC nanocarriers that may be useful in future clinical setting.

Intercrystal self-assembly for the design of high-quality nickel molybdate nanocrystals.

Nanowire of nickel molybdate hydrate, being recognized as an emerging supercapacitor material, was synthesized from the intercrystal self-assembly process (commonly referred to as oriented aggregation or attachment). The detailed lattice image of a NiMoO4·0.75H2O nanowire and the intermediate nanostructure before reaching the interplanar binding were successfully captured by means of high-resolution transmission and scanning electron microscopies. NiMoO4·0.75H2O possessed highly crystalline surface and internal nanostructures.

Monodipserse Nanostructured Spheres of Block Copolymers and Nanoparticles via Cross-Flow Membrane Emulsification

Monodisperse colloidal particles of polystyrene-b-polybutadiene (PS-b-PB) block copolymers (BCPs) were successfully prepared, in which uniform emulsions containing BCPs were first generated by cross-flow membrane emulsification using tubular Shirasu porous glass (SPG) membrane, and then unique internal nanostructures were developed by controlled evaporation of solvent inside emulsion. The diameter of those BCP particles could be controlled from 200 nm to 5 μm by tuning the pore diameter of the membrane. With symmetric BCPs, onion-like nanostructures inside particles were formed. Coiled cylinders in the BCP particles were also developed by adding homopolymers, in which the assembled BCP structure is strongly dependent on the particle size, demonstrating the importance of our membrane method in generating monodisperse BCP particles. Further investigation of process parameters showed that for a given pore diameter, the operation pressure (P) and surfactant concentration were critical parameters for narrow si...

Templated self-assembly of block copolymers and morphology transformation driven by the Rayleigh instability.

In the current study, we investigate the self-assembly of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) confined in the nanopores of the anodic aluminum oxide (AAO) template and the subsequent morphology transformation induced by the Rayleigh instability. PS-b-P4VP nanotubes and nanorods with various internal nanostructures are fabricated by wetting the AAO template with PS-b-P4VP/chloroform solution, and then followed by solvent evaporation. After the removal of AAO template by potassium hydroxide solution, several different solvents (chloroform, toluene, and N,N-dimethylformamide) with different qualities are used to swell and anneal those nanotubes and nanorods suspended in aqueous media. Morphology transformation from nanostructured PS-b-P4VP nanotubes or nanorods to ordered nanospheres is observed by annealing upon chloroform and toluene while the morphology remains unchanged upon N,N-dimethylformamide annealing, indicating that solvent quality is a key factor in tuning the morphology and internal structures. Kinetics study and theoretical analysis for the morphology transition from two-dimensional (2D) block copolymer (BCP) nanotubes and nanorods to three-dimensional (3D) BCP nanospheres are further performed. From the morphological evolution and the quantitative calculation, it is confirmed that this transition is induced by the Rayleigh instability. This study provides a simple but promising method, that is, solvent annealing method, for the fabrication of BCP nanospheres with ordered internal nanostructures, which may have great application in drug delivery and other nanotechnology.

フォノン輸送の視点からのナノ焼結体の熱伝導解析

ABSTRACTOver the last decade, there has been a great enhancement in efficiency of bulk thermoelectric materials by reducing lattice thermal conductivity with internal nanostructures. This includes sintered nanostructures, which has merit in applicability and scalability. While the material development so far has been rather empirical, for further improvement of the bulk nanostructured materials, the need for material design based on prediction of lattice thermal conductivity is growing. This paper reviews recently developed multiscale method to calculate lattice thermal conductivity of bulk crystalline nanostructures. The method seamlessly combines first-principles calculations of interatomic force constants, lattice dynamics calculations of intrinsic phonon transport properties, and Monte Carlo simulation of phonon Boltzmann transport through nanostructures. The method can handle phonon transport through a large system with randomly placed and shaped nanostructures, and thus it is sufficient to quantify how reduction of thermal conductivity of polycrystalline nanostructures depends on mean size and distribution of nano-grains. The results for sintered polycrystalline silicon nanostructure are presented.

Nanostructure and cytotoxicity of self-assembled monoolein–capric acid lyotropic liquid crystalline nanoparticles

Monoolein–capric acid combinations form into particles with internal nanostructures, including inverse hexagonal and bicontinuous cubic mesophases, with differing cytotoxicity.

PEGylation of phytantriol-based lyotropic liquid crystalline particles--the effect of lipid composition, PEG chain length, and temperature on the internal nanostructure.

Poly(ethylene glycol)-grafted 1,2-distearoyl-sn-glycero-3-phosphoethanolamines (DSPE-mPEGs) are a family of amphiphilic lipopolymers attractive in formulating injectable long-circulating nanoparticulate drug formulations. In addition to long circulating liposomes, there is an interest in developing injectable long-circulating drug nanocarriers based on cubosomes and hexosomes by shielding and coating the dispersed particles enveloping well-defined internal nonlamellar liquid crystalline nanostructures with hydrophilic PEG segments. The present study attempts to shed light on the possible PEGylation of these lipidic nonlamellar liquid crystalline particles by using DSPE-mPEGs with three different block lengths of the hydrophilic PEG segment. The effects of lipid composition, PEG chain length, and temperature on the morphology and internal nanostructure of these self-assembled lipidic aqueous dispersions based on phytantriol (PHYT) were investigated by means of synchrotron small-angle X-ray scattering and Transmission Electron Cryo-Microscopy. The results suggest that the used lipopolymers are incorporated into the water-PHYT interfacial area and induce a significant effect on the internal nanostructures of the dispersed submicrometer-sized particles. The hydrophilic domains of the internal liquid crystalline nanostructures of these aqueous dispersions are functionalized, i.e., the hydrophilic nanochannels of the internal cubic Pn3m and Im3m phases are significantly enlarged in the presence of relatively small amounts of the used DSPE-mPEGs. It is evident that the partial replacement of PHYT by these PEGylated lipids could be an attractive approach for the surface modification of cubosomal and hexosomal particles. These PEGylated nanocarriers are particularly attractive in designing injectable cubosomal and hexosomal nanocarriers for loading drugs and/or imaging probes.

Salts drive controllable multilayered upright assembly of amyloid-like peptides at mica/water interface

Surface-assisted self-assembly of amyloid-like peptides has received considerable interest in both amyloidosis research and nanotechnology in recent years. Despite extensive studies, some controlling factors, such as salts, are still not well understood, even though it is known that some salts can promote peptide self-assemblies through the so-called "salting-out" effect. However, they are usually noncontrollable, disordered, amorphous aggregates. Here, we show via a combined experimental and theoretical approach that a conserved consensus peptide NH2-VGGAVVAGV-CONH2 (GAV-9) (from representative amyloidogenic proteins) can self-assemble into highly ordered, multilayered nanofilaments, with surprising all-upright conformations, under high-salt concentrations. Our atomic force microscopy images also demonstrate that the vertical stacking of multiple layers is highly controllable by tuning the ionic strength, such as from 0 mM (monolayer) to 100 mM (mainly double layer), and to 250 mM MgCl2 (double, triple, quadruple, and quintuple layers). Our atomistic molecular dynamics simulations then reveal that these individual layers have very different internal nanostructures, with parallel β-sheets in the first monolayer but antiparallel β-sheets in the subsequent upper layers due to their different microenvironment. Further studies show that the growth of multilayered, all-upright nanostructures is a common phenomenon for GAV-9 at the mica/water interface, under a variety of salt types and a wide range of salt concentrations.