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Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Ecology, Ecologie, Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Formations superficielles, Surficial geology, Sols, Soils, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie animale et végétale, Animal and plant ecology, Synécologie, Synecology, Ecosystèmes terrestres, Terrestrial ecosystems, Carbone, carbon, Carbono, Cinétique, kinetics, Cinética, Cycle carbone, carbon cycle, Ecosystème, ecosystems, Ecosistema, Elément nutritif, nutrients, Nutriente, Enzyme, enzymes, Enzima, Humidité sol, soil moisture, Humedad suelo, Microorganisme, microorganisms, Microorganismo, Milieu aquatique, aquatic environment, Milieu continental, terrestrial environment, Medio continental, Milieu eau douce, fresh-water environment, Medio agua dulce, Milieu marin, marine environment, Medio marino, PH, pH, Sol, soils, Suelo, Température, temperature, Temperatura, Aquatic, Extracellular enzymes, Marine, Microbial communities, Soil, and Terrestrial

Extracellular enzymes produced by heterotrophic microbial communities are major drivers of carbon and nutrient cycling in terrestrial, freshwater, and marine environments. Although carbon and nutrient cycles are coupled on global scales, studies of extracellular enzymes associated with terrestrial, freshwater, and marine microbial communities are not often compared across ecosystems. In part, this disconnect arises because the environmental parameters that control enzyme activities in terrestrial and freshwater systems, such as temperature, pH, and moisture content, have little explanatory power for patterns of enzyme activities in marine systems. Instead, factors such as the functional diversity of microbial communities may explain varying patterns of enzyme activities observed in the ocean to date. In any case, many studies across systems focus on similar issues that highlight the commonalities of microbial community organization. Examples include the effective lifetime of enzymes released into the environment; the extent to which microbial communities coordinate enzyme expression to decompose complex organic substrates; and the influence of microbial community composition on enzyme activities and kinetics. Here we review the often-disparate research foci in terrestrial, freshwater, and marine environments. We consider the extent to which environmental factors may regulate extracellular enzyme activities within each ecosystem, and highlight commonalities and current methodological challenges to identify research questions that may aid in integrating cross-system perspectives in the future.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Agent surface, Surfactant, Agente superficie, Angle contact, Contact angle, Angulo contacto, Article synthèse, Review, Artículo síntesis, Cinétique, Kinetics, Cinética, Effet Marangoni, Marangoni effect, Efecto Marangoni, Evaporation, Evaporación, Gouttelette, Droplet, Gotita, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Mouillage, Wetting, Remojo, Sessile, Sesil, Nanosuspension, Kinetics of evaporation, and Surfactant solution

Recent developments in the studies of evaporation of liquid droplets placed on a solid substrate are reviewed for the droplet size typically larger than 1 μm, so that kinetics effects of evaporation are neglected. The attention is paid to the limits of applicability of classical diffusion model of evaporation, effect of substrate, evaporation of complex fluids and applicability for its description of the theory developed for pure liquids, and hydrothermal waves accompanying evaporation.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biotechnologie, Biotechnology, Tobamovirus, Virus, Antibactérien, Antibacterial agent, Antibacteriano, Argent, Silver, Plata, Cinétique, Kinetics, Cinética, Croissance, Growth, Crecimiento, Nanoparticule, Nanoparticle, Nanopartícula, Polypeptide, Polipéptido, Virus mosaïque tabac, Tobacco mosaic virus, Biomimétique, Biomimetics, Growth kinetics, Heterogeneous reaction, Polypeptides, and Silver nanoparticles

We report simple, facile and size-controllable synthesis of uniform Ag nanoparticles with tobacco mosaic virus (TMV) as a biomediator in the absence of external reducing agents. UV-vis and TEM analysis show that Ag nanoparticles with average diameter of 2, 4 and 9 nm were obtained by simply tuning the ratio of TMV/Ag(NH3)2+. The Ag formation in the presence of TMV showed autocatalytic growth followed by coalescence. The as-prepared TMV-mediated Ag nanoparticles show substantially higher catalytic and antibacterial activities than previous results. For the 4-nitrophenol hydrogenation reaction, the rate constants per surface area for 2 and 9 nm Ag nanoparticles were determined to be 0.64 and 1.2 Lm-2 s-1 respectively. Both Kirby-Bauer disk diffusion test and tube culture results demonstrate high antibacterial activity of TMV-mediated Ag particles against Escherichia coli, with minimal inhibition concentration (MIC) of 2.3 and 2.5 ppm for 2 and 9 nm Ag nanoparticles respectively. We expect that our biomediated Ag synthesis approach can be readily extended to other biomaterials and metal nanoparticle systems.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Préparation, cinétique, thermodynamique, mécanisme et catalyseurs, Preparation, kinetics, thermodynamics, mechanism and catalysts, Polymères à propriétés spéciales, Polymers with particular properties, Cinétique, Kinetics, Cinética, Copolymère biséquencé, Diblock copolymer, Copolímero bisecuencia, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Micellisation, Micellization, Micelización, Méthacrylate de sodium copolymère, Sodium methacrylate copolymer, Metacrilato de sodio copolímero, Méthacrylique acide copolymère, Methacrylic acid copolymer, Metacrílico ácido copolímero, Polymère amphiphile, Amphiphilic polymer, Polímero amfifilo, Polymérisation transfert atome, Atom transfer polymerization, Polimerización transferencia atomo, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Propriété rhéologique, Rheological properties, Propiedad reológica, Préparation, Preparation, Preparación, Relation structure propriété, Property structure relationship, Relación estructura propiedad, Solution aqueuse, Aqueous solution, Solución acuosa, Styrène copolymère, Styrene copolymer, Estireno copolímero, Viscosité cisaillement, Shear viscosity, Viscosidad cizalla, ATRP, Amphiphilic block copolymers, Gel rheology, and Percolation

Following our previous investigation on the effect of molecular architecture on the rheology of Polystyrene-b-Poly(sodium methacrylate) copolymers (PS-b-PMAA), we consider here diblock PS-b-PMAA copolymers characterized by a different length of either the hydrophilic or the hydrophobic block. Various copolymers characterized by different PS or PMAA block length have been prepared by ATRP (kinetics is also discussed) and studied from the point of view of their rheological behaviour in water. To the best of our knowledge, this is the first systematic investigation concerning the effect of block length on the rheology of diblock polyelectrolytes. We found that the hydrophobic block length has small influence on the rheology. Surprisingly, the polymers with shortest PMAA blocks yield the strongest gels at high concentration. A simple model based on the classical theories of self-assembly and percolation of amphiphilic polymers has been here developed in order to explain the observed data.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Atomic molecular physics, Physique atomique et moléculaire, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Alcanol, Alkanol, Alcool, Alcohol, Aliment, Food, Alimento, Catalyseur, Catalyst, Catalizador, Cinétique, Kinetics, Cinética, Corrélation, Correlation, Correlación, Effet solvant, Solvent effect, Efecto solvente, Epoxydation, Epoxidation, Epoxidación, Etat transition, Transition state, Estado transitorio, Ethanol, Etanol, Isomère, Isomer, Isómero, Liaison hydrogène, Hydrogen bond, Enlace hidrógeno, Mécanisme, Mechanism, Mecanismo, Méthode fonctionnelle densité, Density functional method, Oxyde, Oxides, Óxido, Peroxyde d'hydrogène, Hydrogen peroxide, Peróxido de hydrogeno, Réactivité chimique, Chemical reactivity, Reactividad química, Solvant organique, Organic solvent, Solvente orgánico, Stabilisation, Stabilization, Estabilización, density functional calculations, epoxidation, hydrogen bonds, kinetics, and solvent effects

In our attempt to synthesize β-caryophyllene oxide in food-compatible conditions, we observed the uncatalyzed and highly selective epoxidation of β-caryophyllene, a strained bicyclic sesquiterpene, in ethanol with aqueous H2O2 under radical-suppressing conditions without the addition of a catalyst. The unusual reactivity of β-caryophyllene allowed us to use it as a probe for the mechanism of the solvent-assisted epoxidation in a wide range of organic solvents. A kinetic study was performed to investigate the epoxidation mechanism; an excellent correlation was found between the observed epoxidation rates in different solvents and the Abraham's hydrogen bond formation parameters of these solvents. By means of computational analysis, it was found that the main role of the solvent consists of the stabilization of the elongated O―O bond of H2O2 in the transition state through hydrogen-bond donation to the leaving OH moiety of H2O2. α-Humulene was found to possess similar reactivity as β-caryophyllene whereas isocaryophyllene—the unstrained isomer of β-caryophyllene—was unreactive.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Chirurgie (generalites). Transplantations, greffes d'organes et de tissus. Pathologie des greffons, Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases, Technologie. Biomatériaux. Equipements, Technology. Biomaterials. Equipments, Propriété biologique, Biological properties, Propiedad biológica, Propriété mécanique, Mechanical properties, Propiedad mecánica, Acrylamide dérivé copolymère, Acrylamide derivative copolymer, Acrilamida derivado copolímero, Acrylate copolymère, Acrylate copolymer, Acrilato copolímero, Acrylique acide copolymère, Acrylic acid copolymer, Acrílico ácido copolímero, Amidoamine copolymère, Amidoamine copolymer, Amidoamina copolímero, Amidoamine polymère, Amidoamine polymer, Amidoamina polímero, Biocompatibilité, Biocompatibility, Biocompatibilidad, Biodégradabilité, Biodegradability, Biodegradabilidad, Biomatériau, Biomaterial, Cellule mésenchymateuse, Mesenchymal cell, Célula mesenquimatosa, Cellule souche, Stem cell, Célula primitiva, Charpente, Framework, Armadura, Cinétique, Kinetics, Cinética, Copolymérisation radicalaire, Radical copolymerization, Copolimerización radical, Encapsulation, Encapsulación, Etude expérimentale, Experimental study, Estudio experimental, Forme injectable, Injectable form, Forma inyectable, Gonflement, Swelling, Inflamiento, Gélification, Gelation, Gelificación, Génie tissulaire, Tissue engineering, Ingeniería de tejidos, Hydrogel, Hidrogel, Hydrolyse, Hydrolysis, Hidrólisis, In vitro, Module compression, Bulk modulus, Módulo volumétrico, Méthacrylate de glycidyle copolymère, Glycidyl methacrylate copolymer, Metacrilato de glicidilo copolímero, Préparation, Preparation, Preparación, Réticulation, Crosslinking, Reticulación, Solution aqueuse, Aqueous solution, Solución acuosa, Tissu osseux, Osseous tissue, Tejido óseo, Acrylamide(N-isopropyl) copolymère, Copolymère sensible stimuli, Gel hybride, and Quaterpolymère

Injectable, dual-gelling hydrogels were successfully developed through the combination of physical thermogellation at 37 °C and favorable amine:epoxy chemical cross-linking. Poly(N-isopropylacrylamide)-based thermogelling macromers with a hydrolyzable lactone ring and epoxy pendant groups and a biodegradable diamine-functionalized polyamidoamine cross-linker were synthesized, characterized, and combined to produce nonsyneresing and bioresorbable hydrogels. Differential scanning calorimetry and oscillatory rheometry demonstrated the rapid and dual-gelling nature of the hydrogel formation. The postgelation dimensional stability, swelling, and mechanical behavior of the hydrogel system were shown to be easily tuned in the synthesis and formulation stages. The leachable products were found to be cytocompatible under all conditions, while the degradation products demonstrated a dose- and time-dependent response due to solution osmolality. Preliminary encapsulation studies showed mesenchymal stem cell viability could be maintained for 7 days. The results suggest that injectable and thermally and chemically cross-linkable hydrogels are promising alternatives to prefabricated biomaterials for tissue engineering applications, particularly for cell delivery.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Analytical chemistry, Chimie analytique, Pharmacology drugs, Pharmacologie, galénique, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Chimie analytique, Analytical chemistry, Méthodes chromatographiques et méthodes physiques associées à la chromatographie, Chromatographic methods and physical methods associated with chromatography, Méthodes chromatographiques en phase gazeuse, Gas chromatographic methods, Métal transition Complexe, Transition metal Complexes, Metal transición Complejo, Adsorbant, Adsorbent, Adsorbente, Adsorption, Adsorción, Aldéhyde, Aldehyde, Aldehído, Analyse chimique, Chemical analysis, Análisis químico, Analyse quantitative, Quantitative analysis, Análisis cuantitativo, Caractérisation, Characterization, Caracterización, Charpente organométallique, Metal organic framework, Armazòn organometálico, Chromatographie phase gazeuse, Gas chromatography, Cromatografía fase gaseosa, Chrome Complexe, Chromium Complexes, Cromo Complejo, Cinétique, Kinetics, Cinética, Complexe aqua, Aqua complex, Complejo aqua, Complexe oxo, Oxo complex, Complejo oxo, Composé organique volatil, Volatile organic compound, Compuesto orgánico volátil, Coordinat organique, Organic ligand, Ligando orgánico, Diffraction RX, X ray diffraction, Difracción RX, Dégradation photochimique, Photochemical degradation, Degradación fotoquímica, Formaldéhyde, Formaldehyde, Formaldehído, Hydrocarbure, Hydrocarbon, Hidrocarburo, Matériau composite, Composite material, Material compuesto, Matériau poreux, Porous material, Material poroso, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Morphologie, Morphology, Morfología, Méthode couplée, Coupled method, Método acoplado, Nanocomposite, Nanocompuesto, Nanomatériau, Nanostructured materials, Photocatalyse, Photocatalysis, Fotocatálisis, Polluant, Pollutant, Contaminante, Préparation, Preparation, Preparación, Rayonnement UV, Ultraviolet radiation, Radiación ultravioleta, Spectrométrie masse, Mass spectrometry, Espectrometría masa, Structure surface, Surface structure, Estructura superficie, Thermodésorption, Thermodesorption, Desabsorción térmica, Titane IV Oxyde, Titanium IV Oxides, Titanio IV Óxido, Téréphtalate, Terephthalates, o-Xylène, o-Xylene, o-Xileno, GC MS, MIL 101, Metal-organic framework, Thermal desorption, TiO2/MIL-101 nanocomposite, and Volatile pollutants

Nanoscale anatase titania was embedded within the porous chromium terephthalate MIL-101 under low-temperature hydrothermal treatment. The metal-organic framework shell acting as host matrix can effectively prevent the titania nanoparticles from aggregating and enable a good dispersion of these nanoparticles. The X-ray diffraction spectra, transmission electron micrography and X-ray photoelectron spectra clearly showed successful impregnation of the nano-sized anatase titania within the body of MIL-101. The resulting TiO2/MIL-101 nanocomposite was considered as bifunctional material with abundant adsorptive domains and catalytic domains, and was packed in a quartz tube as a convenient trapping and photocatalytic reactor for hazardous volatile pollutants. The composite showed great potential for adsorptive and photocatalytic degradation of these volatile pollutants, such as formaldehyde and o-xylene, which were online monitored by thermal desorption gas chromatography with mass spectrometric detection.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Analytical chemistry, Chimie analytique, Pharmacology drugs, Pharmacologie, galénique, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biochimie analytique, structurale et metabolique, Analytical, structural and metabolic biochemistry, Protéines, Proteins, Généralités, méthodes d'étude, General aspects, investigation methods, Enzyme, Enzima, Glycosidases, Glycosylases, Hydrolases, Adsorbant, Adsorbent, Adsorbente, Adsorption, Adsorción, Capacité adsorption, Adsorption capacity, Capacidad adsorción, Cinétique, Kinetics, Cinética, Composé biochimique, Biochemical compound, Compuesto bioquímico, Lysozyme, Matériau poreux, Porous material, Material poroso, Morphologie, Morphology, Morfología, Mésoporosité, Mesoporosity, Mesoporosidad, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Protéine basique, Basic protein, Proteína básica, Protéine sérique, Serum protein, Proteína sérica, Préparation, Preparation, Preparación, Silice, Silica, Sílice, Sérumalbumine, Serum albumin, Seroalbúmina, Foams, Mesostructured silica, Protein adsorption, and Window size

Mesostructured cellular foam (MCF) silica spheres with different textual parameters were synthesized using a triblock copolymer as a template. The effects of acid concentration and aging time on the window size and morphology were discussed. Besides, the adsorption performances of lysozyme and bovine serum albumin on the blank MCF with different window size and aminopropyl-modified MCFs were studied. The adsorption capacity and rates were shown to be dependent on the window size and surface chemical properties of the adsorbents. In particular, the MCF with window size of 15.2 nm showed fast adsorption for lysozyme with an adsorption capacity of 500 mg/g in 10 min. Furthermore, it has been shown that MCF spheres are potential materials in the separation of biomolecules because of their chemical tunable surface and molecular sieve properties.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Analytical chemistry, Chimie analytique, Pharmacology drugs, Pharmacologie, galénique, Pollution, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie analytique, Analytical chemistry, Méthodes chromatographiques et méthodes physiques associées à la chromatographie, Chromatographic methods and physical methods associated with chromatography, Autres méthodes chromatographiques, Other chromatographic methods, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Méthodes de contrôle, Analysis, Inhibiteur recapture, Reuptake inhibitor, Inhibidor recaptura, Sérotonine, Serotonin, Serotonina, Acrylamide dérivé polymère, Acrylamide derivative polymer, Acrilamida derivado polímero, Adsorbant, Adsorbent, Adsorbente, Allylique dérivé copolymère, Allylic derivative copolymer, Alílico derivado copolímero, Analyse chimique, Chemical analysis, Análisis químico, Analyse quantitative, Quantitative analysis, Análisis cuantitativo, Analyse trace, Trace analysis, Análisis huella, Antidépresseur, Antidepressant agent, Antidepresor, Caractérisation, Characterization, Caracterización, Chromatographie HPLC, HPLC chromatography, Cromatografía HPLC, Cinétique, Kinetics, Cinética, Comprimé enrobé, Coated tablet, Tableta cubierta, Condition opératoire, Operating conditions, Condición operatoria, Copolymère greffé, Graft copolymer, Copolímero injertado, Copolymérisation radicalaire, Radical copolymerization, Copolimerización radical, Détecteur UV, Ultraviolet detector, Detector UV, Effet température, Temperature effect, Efecto temperatura, Enrichissement chimique, Chemical enrichment, Enriquecimiento químico, Enrobage entérique, Enteric coating, Cubierta entérica, Extraction SPE, Solid phase extraction, Extracción SPE, Fluvoxamine, Fluvoxamina, Forme libération contrôlée, Controlled release form, Forma liberación controlada, Forme orale, Oral form, Forma oral, Forme pharmaceutique, Dosage form, Forma farmacéutica, Homme, Human, Hombre, Isotherme Freundlich, Freundlich isotherm, Isoterma Freundlich, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Libération, Release, Liberación, Liquide biologique, Biological fluid, Líquido biológico, Liquide gastrique, Gastric juice, Jugo gástrico, Liquide intestinal, Intestinal juice, Líquido intestinal, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Morphologie, Morphology, Morfología, Nanoparticule, Nanoparticle, Nanopartícula, Neurotransmetteur, Neurotransmitter, Neurotransmisor, Particule magnétique, Magnetic particles, Plasma sanguin, Blood plasma, Plasma sanguíneo, Principe actif, Active ingredient, Principio activo, Préparation échantillon, Sample preparation, Preparación muestreo, Préparation, Preparation, Preparación, Psychotrope, Psychotropic, Psicotropo, Sang, Blood, Sangre, Structure surface, Surface structure, Estructura superficie, Séparation magnétique, Magnetic separation, Separación magnética, Enteric drug delivery, Human biological fluids, Magnetic nano-particles, and Pharmaceutical samples

In this research, a novel method is reported for the surface grafting of N-isopropylacrylamide as a thermosensitive agent and 1-(N,N-bis-carboxymethyl)amino-3-allylglycerol with an affinity toward fluvoxamine onto magnetic nano-particles modified by 3-mercaptopropyltrimethoxysilane. The grafted nano-particles were characterized by Fourier transform infrared spectroscopy, elemental analysis, and thermogravimetric analysis. The surface morphology was studied with scanning electron microscopy and transmission electron microscopy. The resulting grafted nano-particles were used in solid phase extraction and determining of trace fluvoxamine in biological human fluids and pharmaceutical samples. The profile of the fluvoxamine uptake by the modified magnetic nano-particles indicated good accessibility of the active sites in the grafted copolymer. It was found that the adsorption behavior could be fitted by the Freundlich adsorption isotherm model. It was observed that a maximum amount of fluvoxamine was released at a temperature above the lower critical solution temperature of the polymer.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biotechnologie, Biotechnology, Chimie, Chemistry, Química, Chlorure de sodium, Sodium chloride, Sodio cloruro, Cinétique, Kinetics, Cinética, Dénaturation, Denaturation, Desnaturalización, Inhibition, Inhibición, Paramètre cinétique, Kinetic parameter, Parámetro cinético, Protéine, Protein, Proteína, Synergie, Synergism, Sinergia, Thermodynamique, Thermodynamics, Termodinámica, Tréhalose, Trehalose, Trehalosa, Biophysical chemistry, Ferricytochrome c, Kinetic parameters, and Protein denaturation

It is known that trehalose and sodium chloride (NaCl) can both effectively inhibit acid-induced protein denaturation, but the thermodynamic and kinetic behaviors of acid-induced protein unfolding synergistically inhibited by trehalose and NaCl are unclear. In this study, the synergistic inhibition effects of trehalose and NaCl on the acid-induced unfolding of ferricytochrome c were studied at pH 2.0. Thermodynamic parameters were firstly derived based on fluorescence spectroscopic data. Then, kinetic behaviors were studied using stopped-flow fluorescence spectroscopy. It was found that the kinetics of the acid-induced protein unfolding transformed from a triphasic process (i.e., fast, intermediate and slow phases) into a biphasic one (i.e., intermediate and slow phases) and then a single slow phase process with increasing either trehalose or NaCl concentration in the mixture. The rate constants for all the unfolding phases change slightly, while the amplitudes for the fast and intermediate phases diminish greatly with increasing the concentration of trehalose or NaCl. This clearly indicates that the mixture of trehalose and NaCl could synergistically inhibit acid-induced protein unfolding by reducing the extent of protein conformational changes, thus inducing a stable molten-globule state at higher concentrations of the agents.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Protéines, Proteins, Propriété mécanique, Mechanical properties, Propiedad mecánica, Cinétique, Kinetics, Cinética, Contrainte cisaillement, Shear stress, Tensión cizallamiento, Effet composition, Composition effect, Efecto composición, Etude expérimentale, Experimental study, Estudio experimental, Gel physique, Physical gel, Gel físico, Gélification, Gelation, Gelificación, Hydrogel, Hidrogel, Morphologie, Morphology, Morfología, Mécanisme, Mechanism, Mecanismo, Protéine, Protein, Proteína, Relation contrainte déformation, Stress strain relation, Relación tensión deformación, Renforcement mécanique, Strengthening, Refuerzo mecánico, Solution aqueuse, Aqueous solution, Solución acuosa, Structure fibrillaire, Fibrillar structure, Estructura fibrilar, Synergie, Synergism, Sinergia, Viscoélasticité, Viscoelasticity, Viscoelasticidad, Gel mixte, and Rhéocinétique

Many biological materials are composite structures, interpenetrating networks of different types of fibers. The composite nature of such networks leads to superior mechanical properties, but the origin of this mechanical synergism is still poorly understood. Here we study soft composite networks, made by mixing two self-assembling fiber-forming components. We find that the elastic moduli of the composite networks significantly exceed the sum of the moduli of the two individual networks. This mechanical enhancement is in agreement with recent simulations, where it was attributed to a suppression of non-affine deformation modes in the most rigid fiber network due to the reaction forces in the softer network. The increase in affinity also causes a loss of strain hardening and an increase in the critical stress and stain at which the network fails.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Atomic molecular physics, Physique atomique et moléculaire, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Gel colloïdal, Colloidal gel, Gel coloidal, Acrylamide dérivé copolymère, Acrylamide derivative copolymer, Acrilamida derivado copolímero, Acrylamide polymère, Acrylamide polymer, Acrilamida polímero, Acrylique acide copolymère, Acrylic acid copolymer, Acrílico ácido copolímero, Cinétique, Kinetics, Cinética, Gonflement, Swelling, Inflamiento, Hydrogel, Hidrogel, hydrogel, kinetics, microgel, stimuli-responsive gels, and swelling

Composite hydrogels—macroscopic hydrogels with embedded microgel particles—are expected to respond to external stimuli quickly because microgels swell much faster than bulky gels. In this work, the kinetics of the pH-induced swelling of a composite hydrogel are studied using turbidity measurements. The embedded microgel is a pH- and thermosensitive poly(N-isopropylacrylamide-co-acrylic acid) microgel and the hydrogel matrix is polyacrylamide. A rapid pH-induced swelling of the embedded microgel particles is observed, confirming that composite hydrogels respond faster than ordinary hydrogels. However, compared with the free microgels, the swelling of the embedded microgel is much slower. Diffusion of OH- into the composite hydrogel film is identified as the main reason for the slow swelling of the embedded microgel particles, as the time of the pH-induced swelling of this film is comparable to that of OH- diffusion into the film. The composition of the hydrogel matrix does not significantly change the characteristic swelling time of the composite hydrogel film. However, the swelling pattern of the film changes with composition of the hydrogel matrix.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Propriété biologique, Biological properties, Propiedad biológica, Amidation, Amidación, Antigène, Antigen, Antígeno, Cinétique, Kinetics, Cinética, Copolymère greffé, Graft copolymer, Copolímero injertado, Cytotoxicité, Cytotoxicity, Citotoxicidad, Etude expérimentale, Experimental study, Estudio experimental, Expression génique, Gene expression, Expresión genética, In vitro, Internalisation, Internalization, Internalización, Libération, Release, Liberación, Macrophage, Macrófago, Mannane, Mannan, Mannano, Modification chimique, Chemical modification, Modificación química, Méthacrylamide copolymère, Methacrylamide copolymer, Metacrilamida copolímero, Méthacrylate d'hydroxyéthyle copolymère, Hydroxyethyl methacrylate copolymer, Metacrilato de hidroxietilo copolímero, Méthacrylique acide copolymère, Methacrylic acid copolymer, Metacrílico ácido copolímero, Nanogel, Ovalbumine, Ovalbumin, Ovalbúmina, Polymère vecteur, Control release polymer, Polímero vector, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Préparation, Preparation, Preparación, Réaction surface, Surface reaction, Reacción superficie, Réponse immune, Immune response, Respuesta inmune, Terpolymère, Terpolymer, Terpolímero, Vaccin, Vaccine, Vacuna, Voie orale, Oral administration, Vía oral, pH, and Mannane(carboxyméthyl)

Oral drug delivery is a route of choice for vaccine administration because of its noninvasive nature and thus efforts have focused on efficient delivery of vaccine antigens to mucosal sites. An effective oral vaccine delivery system must protect the antigen from degradation upon mucosal delivery, penetrate mucosal barriers, and control the release of the antigen and costimulatory and immunomodulatory agents to specific immune cells (i.e., APCs). In this paper, mannan-modified pH-responsive P(HEMA-co-MAA) nanogels were synthesized and assessed as carriers for oral vaccination. The nanogels showed pH-sensitive properties, entrapping and protecting the loaded cargo at low pH values, and triggered protein release after switching to intestinal pH values. Surface decoration with mannan as carbohydrate moieties resulted in enhanced internalization by macrophages as well as increasing the expression of relevant costimulatory molecules. These findings indicate that mannan-modified P(HEMA-co-MAA) nanogels are a promising approach to a more efficacious oral vaccination regimen.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Chemical engineering, Génie chimique, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Etat colloïdal et états dispersés, Colloidal state and disperse state, Matériaux poreux, Porous materials, Membranes, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Résines échangeuses et membranes, Exchange resins and membranes, Mammalia, Rodentia, Vertebrata, Ammoniac, Ammonia, Amoníaco, Bioréacteur, Bioreactor, Biorreactor, Cellule, Cell, Célula, Cinétique, Kinetics, Cinética, Foie, Liver, Hígado, Membrane polymère, Polymeric membrane, Membrana polímero, Membrane poreuse, Porous membrane, Membrana porosa, Microporosité, Microporosity, Microporosidad, Modèle, Models, Modelo, Mouillabilité, Wettability, Remojabilidad, Oxygène, Oxygen, Oxígeno, Propène polymère, Propylene polymer, Propeno polímero, Rat, Rata, Consumption kinetics, Liver cells, and Membrane wettability

Polymeric membranes used in bioreactors for bioartificial livers are generally chosen for their transport and separation properties to provide liver cells with adequate nutrients supply and avoid rejection. Possible effects of membrane surface properties on cell metabolism are generally given little consideration. The reported effects of membrane surface wettability on adherent liver cells are qualitative and inconsistent, possibly due to the variation of other surface properties and the culture in Petri dishes, often at confluence, under uncontrolled time- and space-varying metabolite concentrations. In this investigation, rat liver cells were cultured in sub-confluent adhesion on model membranes hydrophilized by physical treatment featuring varying surface wettability in a continuous-flow recycle bioreactor. Bioreactor optimization permitted to culture cells at uniform and measurable pericellular concentrations of metabolic substrates, and to challenge them with controlled increasing ammonia concentrations. Membrane surface wettability was characterized in terms of water sorption, dynamic contact angle, and oxygen content by XPS. The kinetics of oxygen consumption, ammonia elimination and urea synthesis of cells adherent on membranes with increasing wettability was characterized at increasing ammonia concentrations. Cells exhibited increasingly better metabolic functions on membranes with increasing surface wettability. Metabolic reaction rate differences were increasingly more evident at increasing ammonia concentrations. Membrane surface wettability appeared to mainly affect cell capacity to respond to the ammonia challenge.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Composé binaire, Binary compound, Compuesto binario, Adsorption, Adsorción, Cinétique, Kinetics, Cinética, Matériau composite, Composite material, Material compuesto, Mouillage, Wetting, Remojo, Mécanisme, Mechanism, Mecanismo, Nanotube carbone, Carbon nanotubes, Propriété surface, Surface properties, Propiedad superficie, Silice, Silica, Sílice, SiO2, Adsorption mechanism, Cement-based composites, Electro-kinetic potential, Silica adsorption, and Wetting behaviour

In order to improve the embedding of carbon nanotubes (CNTs) in cement-based matrices, silica was deposited on the sidewall of CNTs by a sol-gel method. Knowledge of the conditions of CNTs' surfaces is a key issue in understanding the corresponding interaction mechanisms. In this study various types of CNTs synthesized using acetonitrile, cyclohexane, and methane were investigated with regard to their physicochemical surface properties. Significant differences in surface polarity as well as in the wetting properties of the CNTs, depending on the precursors used, were revealed by combining electro-kinetic potential and contact angle measurements. The hydrophobicity of CNTs decreases by utilising the carbon sources in the following order: cyclohexane, methane, and finally acetonitrile. The XPS analysis, applied to estimate the chemical composition at the CNT surface, showed nitrogen atoms incorporated into the tube structure by using acetonitrile as a carbon source. It was found that the simultaneous presence of nitrogen- and/or oxygen-containing sites with different acid-base properties increased the surface polarity of the CNTs, imparting amphoteric characteristics to them and improving their wetting behaviour. Regarding the silica deposition, strong differences in adsorption capacity of the CNTs were observed. The mechanism of silica adsorption through interfacial bond formation was discussed.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Analytical chemistry, Chimie analytique, Pharmacology drugs, Pharmacologie, galénique, Pollution, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biochimie analytique, structurale et metabolique, Analytical, structural and metabolic biochemistry, Protéines, Proteins, Généralités, méthodes d'étude, General aspects, investigation methods, Adsorbant affinité, Affinity adsorbent, Adsorbente afinidad, Adsorption, Adsorción, Application industrielle, Industrial application, Aplicación industrial, Automatisation, Automation, Automatización, Chromatographie IMAC, Immobilized metal affinity chromatography, Cromatografía IMAC, Chromatographie affinité, Affinity chromatography, Cromatografía afinidad, Cinétique, Kinetics, Cinética, Complexe dinucléaire, Dinuclear complex, Complejo dinuclear, Complexe mu, Mu complex, Complejo mu, Coordinat tridenté, Tridentate ligand, Ligando tridentado, Cuivre Complexe, Copper Complexes, Cobre Complejo, Fixation biologique, Biological fixation, Fijación biológica, Isotherme Langmuir, Langmuir isotherm, Isoterma Langmuir, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Marquage affinité, Affinity labelling, Marcación afinidad, Méthode séparation, Separation method, Método separación, Nickel Complexe, Nickel Complexes, Niquel Complejo, Protéine recombinante, Recombinant protein, Proteína recombinante, Purification, Purificación, Zinc Complexe, Zinc Complexes, Zinc Complejo, 1,4,7-Triazacyclononane dérivé, Binding affinity, HTS, Industrial applications, Metal affinity tag, and Protein binding kinetics

This study describes the determination of the adsorption isotherms and binding kinetics of tagged recombinant proteins using a recently developed IMAC cassette system and employing automated robotic liquid handling procedures for IMAC resin screening. These results confirm that these new IMAC resins, generated from a variety of different metal-charged binuclear 1,4,7-triaza-cyclononane (tacn) ligands, interact with recombinant proteins containing a novel N-terminal metal binding tag, NT1A, with static binding capacities similar to those obtained with conventional hexa-His tagged proteins, but with significantly increased association constants. In addition, higher kinetic binding rates were observed with these new IMAC systems, an attribute that can be positively exploited to increase process productivity. The results from this investigation demonstrate that enhancements in binding capacities and affinities were achieved with these new IMAC resins and chosen NT1A tagged protein. Further, differences in the binding performances of the bis(tacn) xylenyl-bridged ligands were consistent with the distance between the metal binding centres of the two tacn moieties, the flexibility of the ligand and the potential contribution from the aromatic ring of the xylenyl group to undergo π/πt stacking interactions with the tagged proteins.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Ecology, Ecologie, Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Hydrologie. Hydrogéologie, Hydrology. Hydrogeology, Hydrologie, Hydrology, Hydrogéologie, Hydrogeology, Amérique du Nord, North America, America del norte, Aquifère, aquifers, Bassin versant, drainage basins, Cuenca, Carbone organique dissout, dissolved organic carbon, Carbone organique, organic carbon, Carbono orgánico, Cinétique, kinetics, Cinética, Concentration, concentration, Concentración, Cours eau, streams, Curso agua, Dilution, dilution, Dilución, Débit, discharge, Gasto, Eau souterraine, ground water, Agua subterránea, Ecoulement cours eau, streamflow, Forêt, forests, Bosque, Horizon sol, soil horizons, Lessivage, leaching, Lavado con lejía, Matière en suspension, suspended materials, Materia en suspensión, Mixage, mixing, Mezcla, Ouragan, hurricanes, Huracán, Ruissellement, runoff, Brillo, Saturation, saturation, Saturación, Tempête, storms, Tempestad, Transport, transport, Transporte, Climate change, Organic carbon, Runoff, Storm events, Water quality, and Watersheds

This study compared the storm event patterns, sources, and flow paths for particulate (POC) and dissolved organic carbon (DOC <0.45 (μm) with a special focus on responses during large storm events. The study was conducted in a 12 ha forested catchment in the mid-Atlantic, Piedmont region of USA. A total of 14 storm events were sampled over a 16-month period (September 2010 to December 2011) including large, intense storms (precipitation >150 mm) associated with two hurricanes—Nicole (2010) and Irene (2011). Storm-event concentrations for suspended sediment (SS), POC and DOC varied between 10-7589, 0.05-252, and 0.7-18.3 mg L-1, respectively. Within-event POC concentrations continued to increase for the large hurricane storms whereas DOC displayed a dilution at peak streamflow discharge. Flow-weighted mean POC concentrations decreased for closely spaced, successive storm events whereas no such decrease was observed for DOC. These results suggest that there are important differences in the supply and transport (leaching rates and kinetics) for POC and DOC which occur at different temporal scales. The % POC content of SS was highest for the summer events. Summer events also registered a sharper increase in DOC with stream discharge and then a decline for peak flow, suggesting critical seasonal controls on storm-event POC and DOC responses. End-member mixing analysis revealed POC is transported with surface runoff while DOC is transported by saturation overland flow and rising groundwater into the soil horizons. A mixing model for sediment sources failed to identify key end-members but event mixing patterns revealed near-stream sources for small events and more distal, upland sediment sources for large and intense storms. This study highlights the need to better understand POC and DOC responses in headwater catchments especially for the large, intense, storm events that are predicted to increase in intensity with climate change.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Protéines, Proteins, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Enzyme, Enzima, Hydrolases, Cinétique, Kinetics, Cinética, Composé biomimétique, Biomimetic compound, Compuesto biomimético, Dégradation enzymatique, Enzymatic digestion, Degradación enzimática, Elastine, Elastin, Elastina, Etude expérimentale, Experimental study, Estudio experimental, Libération, Release, Liberación, Peptidases, Polymère vecteur, Control release polymer, Polímero vector, Protéine fluorescente verte, Green fluorescent protein, Proteína fluorescente verde, Protéine recombinante, Recombinant protein, Proteína recombinante, Vecteur médicament, Drug carrier, and Vector medicamento

Stimuli-responsive hydrogel matrices have attracted great attention in biomedical and biotechnological fields for controlled delivery of bioactive compounds, as well as a vehicle for therapeutic cell spreading. Elastin-derived biomimetic polypeptides are recombinant macromolecules suitable for the realization of smart biomaterials. In this study, we explored the potential of an elastin biomimetic matrix to realize proteolytic stimuli-responsive systems to control the release of substances. Our approach showed that this matrix was susceptible to elastolytic degradation, and it has been successfully employed to obtain an efficient delivery of a model protein. This setup will constitute a therapeutic agent delivery platform to realize devices capable of responding and interacting with biological systems at the molecular level.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Divers, Miscellaneous, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Oside polymère, Oside polymer, Osido polímero, Peptide polymère, Aminoacid polymer, Péptido polímero, Propriété biologique, Biological properties, Propiedad biológica, Protéine, Protein, Proteína, Antigène, Antigen, Antígeno, Arginine polymère, Arginine polymer, Arginina polímero, Cellule épithéliale, Epithelial cell, Célula epitelial, Cinétique, Kinetics, Cinética, Cytotoxicité, Cytotoxicity, Citotoxicidad, Distribution dimension particule, Particle size distribution, Distribución dimensión partícula, Dérivé du dextrane, Dextran derivatives, Dextrano derivado, Etude expérimentale, Experimental study, Estudio experimental, Expression génique, Gene expression, Expresión genética, Fabrication, Manufacturing, Fabricación, In vitro, Internalisation, Internalization, Internalización, Libération, Release, Liberación, Matériau nanoporeux, Nanoporous materials, Microencapsulation, Microencapsulación, Microparticule, Microparticle, Micropartícula, Morphologie, Morphology, Morfología, Ovalbumine, Ovalbumin, Ovalbúmina, Polymère vecteur, Control release polymer, Polímero vector, Séchage pulvérisation, Spray drying, Secado pulverización, Sérumalbumine, Serum albumin, Seroalbúmina, Vaccin, Vaccine, Vacuna, Voie orale, Oral administration, Vía oral, Dextrane sulfate, and Vaccin oral

During the past decade, extensive research has undeniably improved the formulation and delivery of oral vaccines. Nevertheless, several factors, such as the harsh gastrointestinal environment together with tolerance induction to exogenous antigens, have thus far impeded the optimal effectiveness and clinical application of oral delivery systems. The current study encompasses an initial evaluation of the stability, biocompatibility, and cellular uptake of two promising candidate systems for oral antigen delivery, that is, calcium carbonate- (CP) and mannitol-templated (MP) porous microspheres. Both spray-dried formulations were efficiently internalized by human intestinal epithelial cells (Caco-2 and HT-29) and degraded into phagolysosomal intracellular compartments. In addition, cellular particle uptake and processing significantly up-regulated the expression of (HLA) class-II and costimulatory molecules on intestinal epithelial cells. Even though the high surface-area-to-volume ratio of the microspheres was expected to favor protease access, antigen release was remarkably limited in simulated intestinal fluid and was even absent under gastric conditions. Finally, neither CP nor MP exerted cytotoxicity upon prolonged in vitro incubation with high antigen concentration. Altogether, these data support the potential of CP and MP for oral antigen delivery and motivate the further development of these promising carrier systems in in vivo studies.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Atomic molecular physics, Physique atomique et moléculaire, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Cinétique, Kinetics, Cinética, Formation motif, Patterning, Formacíon motivo, Lithographie, Lithography, Litografía, Nanostructure, Nanoestructura, Nanotechnologie, Nanotechnology, Nanotecnología, Procédé thermochimique, Thermochemical processes, Vitesse déplacement, Speed, Velocidad desplazamiento, kinetics, lithography, nanostructures, nanotechnology, and thermochemistry

Thermochemical nanolithography (TCNL) is a high-resolution lithographic technique and, owing to its fast speed, versatility, and unique ability to fabricate arbitrary, gray-scale nanopatterns, this scanning probe technique is relevant both for fundamental scientific research as well as for nanomanufacturing applications. In this work, we study the dependence of the TCNL driven chemical reactions on the translation speed of the thermal cantilever. The experimental data compares well with a model of the chemical kinetics for a first-order reaction. The impact of higher order reactions on the optimization of TCNL is addressed. The reported quantitative description of the speed dependence of TCNL is exploited and illustrated by fabricating controlled gradients of chemical concentration.