A liver-targeting Cu(i) chelator relocates Cu in hepatocytes and promotes Cu excretion in a murine model of Wilson's disease.

Copper chelation is the most commonly used therapeutic strategy nowadays to treat Wilson's disease, a genetic disorder primarily inducing a pathological accumulation of Cu in the liver. The mechanism of action of Chel2, a liver-targeting Cu(i) chelator known to promote intracellular Cu chelation, was studied in hepatic cells that reconstitute polarized epithelia with functional bile canaliculi, reminiscent of the excretion pathway in the liver. The interplay between Chel2 and Cu localization in these cells was demonstrated through confocal microscopy using a fluorescent derivative and nano X-ray fluorescence.

Automated Buildup of Biomimetic Films in Cell Culture Microplates for High-Throughput Screening of Cellular Behaviors.

An automatic method is established for layer-by-layer (LbL) assembly of biomimetic coatings in cell culture microplates using a commercial liquid-handling robot. Highly homogeneous thin films are formed at the bottom of each microwell. The LbL film-coated microplates are compatible with common cellular assays, using microplate readers and automated microscopes.

In Vitro Dermal Safety Assessment of Silver Nanowires after Acute Exposure: Tissue vs. Cell Models.

Silver nanowires (AgNW) are attractive materials that are anticipated to be incorporated into numerous consumer products such as textiles, touchscreen display, and medical devices that could be in direct contact with skin. There are very few studies on the cellular toxicity of AgNW and no studies that have specifically evaluated the potential toxicity from dermal exposure. To address this question, we investigated the dermal toxicity after acute exposure of polymer-coated AgNW with two sizes using two models, human primary keratinocytes and human reconstructed epidermis.

Visible light-induced insulin aggregation on surfaces via photoexcitation of bound thioflavin T.

Insulin is known to form amyloid aggregates when agitated in a hydrophobic container. Amyloid aggregation is routinely measured by the fluorescence of the conformational dye thioflavin T, which, when incorporated into amyloid fibers, fluoresces at 480 nm. The kinetics of amyloid aggregation in general is characterized by an initial lag-phase, during which aggregative nuclei form on the hydrophobic surface.

Stiffness-dependent cellular internalization of matrix-bound BMP-2 and its relation to Smad and non-Smad signaling.

Unlabelled: Surface coatings delivering BMP are a promising approach to render biomaterials osteoinductive. In contrast to soluble BMPs which can interact with their receptors at the dorsal side of the cell, BMPs presented as an insoluble cue physically bound to a biomimetic matrix, called here matrix-bound (bBMP-2), are presented to cells by their ventral side. To date, BMP-2 internalization and signaling studies in cell biology have always been performed by adding soluble (sBMP-2) to cells adhered on cell culture plates or glass slides, which will be considered here as a "reference" condition.

Micropore-induced capillarity enhances bone distribution in vivo in biphasic calcium phosphate scaffolds.

Unlabelled: The increasing demand for bone repair solutions calls for the development of efficacious bone scaffolds. Biphasic calcium phosphate (BCP) scaffolds with both macropores and micropores (MP) have improved healing compared to those with macropores and no micropores (NMP), but the role of micropores is unclear. Here, we evaluate capillarity induced by micropores as a mechanism that can affect bone growth in vivo.

Control of the Proliferation/Differentiation Balance in Skeletal Myoblasts by Integrin and Syndecan Targeting Peptides.

Controlling the different steps of cell differentiation in vitro using bioactive surfaces may be useful in view of future cell therapies. Substrates presenting peptides, which are minimal fragments of extracellular matrix (ECM) proteins may be used for this purpose. In this work, we used polyelectrolyte multilayer films presenting two peptides derived from different muscle ECM proteins to target syndecan or/and integrin receptors.

Assessment of a polyelectrolyte multilayer film coating loaded with BMP-2 on titanium and PEEK implants in the rabbit femoral condyle.

Unlabelled: The aim of this study was to evaluate the osseointegration of titanium implants (Ti-6Al-4V, noted here TA6V) and poly(etheretherketone) PEEK implants induced by a BMP-2-delivering surface coating made of polyelectrolyte multilayer films. The in vitro bioactivity of the polyelectrolyte film-coated implants was assessed using the alkaline phosphatase assay. BMP-2-coated TA6V and PEEK implants with a total dose of 9.

Bio-functionalization of silicon carbide nanostructures for SiC nanowire-based sensors realization.

The bio-functionalization process consisting in grafting desoxyribo nucleic acid via aminopropyl-triethoxysilane is performed on several kinds of silicon carbide nanostructures. Prior, the organic layer is characterized on planar surface with fluorescence microscopy and X-ray photoelectron spectroscopy. Then, the functionalization is performed on two kinds of nanopillar arrays.

Thiol-ene clickable hyaluronans: from macro-to nanogels.

The fabrication of hyaluronic acid (HA) nanogels using a thiol-ene reaction has been demonstrated. HA was modified with pentenoate groups and then cross-linked with poly(ethylene glycol)-bis(thiol) by exposure to UV light. The cross-linking density and thereby the rigidity of the obtained gels were precisely controlled by the degree of substitution of pentenoate-modified HA.

Interference of CuO nanoparticles with metal homeostasis in hepatocytes under sub-toxic conditions.

Copper oxide nanoparticles (CuO-NP) were studied for their toxicity and mechanism of action on hepatocytes (HepG2), in relation to Cu homeostasis disruption. Indeed, hepatocytes, in the liver, are responsible for the whole body Cu balance and should be a major line of defence in the case of exposure to CuO-NP. We investigated the early responses to sub-toxic doses of CuO-NP and compared them to equivalent doses of Cu added as salt to see if there is a specific nano-effect related to Cu homeostasis in hepatocytes.

Photochemical crosslinking of hyaluronic acid confined in nanoemulsions: towards nanogels with a controlled structure.

We present the preparation of nanogels made of hyaluronic acid (HA) with a well-controlled structure. To this end, HA precursors with polymerizable methacrylate groups (HA-MA) were confined within water-in-oil nanoemulsion droplets as nanoreactors and further photopolymerized under UV. Particular attention was paid to the preparation of a stable nanoemulsion template with a homogeneous droplet size.

Poly(ethylene glycol) hydroxystearate-based nanosized emulsions: effect of surfactant concentration on their formation and ability to solubilize quercetin.

Quercetin is a natural compound that has shown several biological activities. However, it displays poor water solubility and, therefore, low bioavailability. In this study, oil-in-water nanosized emulsions were obtained by the hot solvent diffusion method, using castor oil as oily phase and poly(ethylene glycol) (660)-12-hydroxystearate (PEG 660-stearate) and lecithin as surfactants.

Thermoresponsive self-assemblies of cyclic and branched oligosaccharide-block-poly(N-isopropylacrylamide) diblock copolymers into nanoparticles.

This paper discusses the thermoresponsive nanoparticles obtained by self-assemblies of nonlinear oligosaccharide-based diblock copolymer systems. These diblock copolymers were synthesized by Cu(I)-catalyzed 1,3-dipolar azide/alkyne cycloaddition ("click" reaction) of propargyl-functionalized β-cyclodextrin (βCyD) and xyloglucooligosaccharide (XGO) with poly(N-isopropylacrylamide) (PNIPAM) having a terminal azido group prepared by atom transfer radical polymerization (ATRP). Elastic and quasi-elastic light scattering analysis of the dibock copolymers in H(2)O indicated that thermodynamic phase transitions of the PNIPAM blocks at their cloud points (T(cp)s ≈ 34 °C), around lower critical solution temperatures (LCSTs), triggered their self-assemblies into the nanoparticles.

Elaboration of chitosan-coated nanoparticles loaded with curcumin for mucoadhesive applications.

Polycaprolactone (PCL) nanoparticles decorated with a mucoadhesive polysaccharide chitosan (CS) containing curcumin were developed aiming the buccal delivery of this drug. These nanoparticles were prepared by the nanoprecipitation method using different molar masses and concentrations of chitosan and concentrations of triblock surfactant poloxamer (PEO-PPO-PEO), in order to optimize the preparation conditions. Chitosan-coated nanoparticles showed positive surface charge and a mean particle radius ranging between 114 and 125 nm, confirming the decoration of the nanoparticles with the mucoadhesive polymer, through hydrogen bonds between ether and amino groups from PEO and CS, respectively.

Self-assembly of amphiphilic glycoconjugates into lectin-adhesive nanoparticles.

This work describes the synthesis and self-assembly of carbohydrate-clicked rod-coil amphiphilic systems. Copper-catalyzed Huisgen cycloaddition was efficiently employed to functionalize the hydrophilic extremity of PEG-b-tetra(p-phenylene) conjugates by lactose and N-acetyl-glucosamine ligands. The resulting amphiphilic systems spontaneously self-assembled into nanoparticles when dissolved in aqueous media, as evidenced by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS).

Thermoresponsive vesicular morphologies obtained by self-assemblies of hybrid oligosaccharide-block-poly(N-isopropylacrylamide) copolymer systems.

This work discusses the self-assembly properties of thermoresponsive hybrid oligosaccharide-block-poly(N-isopropylacrylamide) copolymer systems: maltoheptaose-block-poly(N-isopropylacrylamide) (Mal(7)-b-PNIPAM(n)) copolymers. Those systems at different molar masses and volume fractions were synthesized using Cu(I)-catalyzed 1,3-dipolar azide/alkyne cycloaddition, so-called "click" chemistry, between an alkynyl-functionalized maltoheptaose (1) and poly(N-isopropylacrylamide) having a terminal azido group (N(3)-PNIPAM(n)) prepared by atom transfer radical polymerization (ATRP). While the cloud point (T(cp)) of the N(3)-PNIPAM(n) ranged from 36.

Design and synthesis of novel hybrid metal complex-DNA conjugates: key building blocks for multimetallic linear DNA nanoarrays.

We describe here a short and efficient synthetic route for incorporating terpyridine based metal complexes at the 3'-extremity of both single and bis-oligonucleotide (bis-ODN) stretches to form novel metal complex-ODN conjugates. All single stranded mono and bis-ODN tethered metal complexes and the respective duplex ODNs were characterized by circular dichroism spectroscopy and UV-Vis melting experiments. Duplexes formed by these hybrid metal complex-DNA conjugates showed around 4-5 degrees C stabilization with respect to the unmodified duplexes.

Aging and yielding in a sheared AOT/iso-octane/water lyotropic lamellar phase.

We define a creep-flow-based measurement procedure to allow reliable and reproducible results on aging and yielding materials to be obtained. Investigation of the effects of different parameter such as the pre-shear time, the recovery time and the applied stress magnitude on the viscoelastic properties of a lyotropic liquid crystal phase is reported. Cryo-TEM observations indicate the formation of multiconnected bilayers at rest.

Development of a sialic acid-containing hydrogel of poly[N-(2-hydroxypropyl) methacrylamide]: characterization and implantation study.

This study describes the preparation and the characterization of poly[ N-(2-hydroxypropyl methacrylamide)] hydrogel with bulk-modified saccharidic portion of ganglioside GM 3 (Neu5Ac-alpha2,3-Gal-beta1,4-Glc). The 3'-sialyllactose is a bioactive epitope recognized by many cell surface receptors on viruses, bacteria, and human cells such as growth factor receptors. Acrylated 3'-sialyllactose was synthesized and incorporated into the macromolecular network of hydrogels by free radical cross-linking copolymerization.

Multilayer assembly of hyaluronic acid/poly(allylamine): control of the buildup for the production of hollow capsules.

The objective of this work was to investigate the formation of hollow microcapsules composed of hyaluronic acid (HA) and poly(allylamine) (PAH) by layer-by-layer adsorption on CaCO 3 microparticles and subsequent core removal by addition of chelating agents for calcium ions. We found that the molecular weight of HA as well as the HA solution concentration used during deposition are crucial parameters influencing the multilayer structure. Whereas the effect of molecular weight of HA was mainly attributed to the porous structure of the template which allows penetration of polyelectrolytes when their size is below the maximum pore size of the template ( approximately 60 nm), that of the concentration of the HA solution was related to the intrinsic properties of the polysaccharide.

Developmentally regulated association of plastid division protein FtsZ1 with thylakoid membranes in Arabidopsis thaliana.

FtsZ is a key protein involved in bacterial and organellar division. Bacteria have only one ftsZ gene, while chlorophytes (higher plants and green alga) have two distinct FtsZ gene families, named FtsZ1 and FtsZ2. This raises the question of why chloroplasts in these organisms need distinct FtsZ proteins to divide.

The plastid division proteins, FtsZ1 and FtsZ2, differ in their biochemical properties and sub-plastidial localization.

Plastid division in higher plants is morphologically similar to bacterial cell division, with a process termed binary fission involving constriction of the envelope membranes. FtsZ proteins involved in bacterial division are also present in higher plants, in which the ftsZ genes belong to two distinct families: ftsZ1 and ftsZ2. However, the roles of the corresponding proteins FtsZ1 and FtsZ2 in plastid division have not been determined.