Antibody-functionalized polymer-coated gold nanoparticles targeting cancer cells: an in vitro and in vivo study

Gold nanoparticles ( 3c5 nm) coated with plasma-polymerized allylamine were produced through plasma vapor deposition and bioconjugated with a monoclonal antibody targeting the epidermal growth factor receptor. The resulting nanoconjugates displayed an antibody loading of about 1.7 nmol mg -1 and efficiently target epidermal growth factor receptor overexpressing cell lines, as ascertained by ELISA and Western blot assays. The in vitro targeting properties were also confirmed in vivo, where a similar biodistribution profile of what was experienced for the unconjugated antibody was observed. Thanks to the possibility of doping the gold nanoparticles with radionuclides during plasma vapor deposition, the proposed functionalization strategy represents a very suitable platform for the in vivo cancer targeting with nanosized multifunctional particles. This journal is \ua9 2012 The Royal Society of Chemistry

The association of N-palmitoylethanolamine with the FAAH inhibitor URB597 impairs melanoma growth through a supra-additive action

<p>Abstract</p> <p>Background</p> <p>The incidence of melanoma is considerably increasing worldwide. Frequent failing of classical treatments led to development of novel therapeutic strategies aiming at managing advanced forms of this skin cancer. Additionally, the implication of the endocannabinoid system in malignancy is actively investigated.</p> <p>Methods</p> <p>We investigated the cytotoxicity of endocannabinoids and their hydrolysis inhibitors on the murine B16 melanoma cell line using a MTT test. Enzyme and receptor expression was measured by RT-PCR and enzymatic degradation of endocannabinoids using radiolabeled substrates. Cell death was assessed by Annexin-V/Propidium iodine staining. Tumors were induced in C57BL/6 mice by s.c. flank injection of B16 melanoma cells. Mice were injected i.p. for six days with vehicle or treatment, and tumor size was measured each day and weighted at the end of the treatment. Haematoxylin-Eosin staining and TUNEL assay were performed to quantify necrosis and apoptosis in the tumor and endocannabinoid levels were quantified by HPLC-MS. Tube formation assay and CD31 immunostaining were used to evaluate the antiangiogenic effects of the treatments.</p> <p>Results</p> <p>The <it>N</it>-arachidonoylethanolamine (anandamide, AEA), 2-arachidonoylglycerol and <it>N</it>- palmitoylethanolamine (PEA) reduced viability of B16 cells. The association of PEA with the fatty acid amide hydrolase (FAAH) inhibitor URB597 considerably reduced cell viability consequently to an inhibition of PEA hydrolysis and an increase of PEA levels. The increase of cell death observed with this combination of molecules was confirmed in vivo where only co-treatment with both PEA and URB597 led to decreased melanoma progression. The antiproliferative action of the treatment was associated with an elevation of PEA levels and larger necrotic regions in the tumor.</p> <p>Conclusions</p> <p>This study suggests the interest of targeting the endocannabinoid system in the management of skin cancer and underlines the advantage of associating endocannabinoids with enzymatic hydrolysis inhibitors. This may contribute to the improvement of long-term palliation or cure of melanoma.</p

Modeling Brain Resonance Phenomena Using a Neural Mass Model

Stimulation with rhythmic light flicker (photic driving) plays an important role in the diagnosis of schizophrenia, mood disorder, migraine, and epilepsy. In particular, the adjustment of spontaneous brain rhythms to the stimulus frequency (entrainment) is used to assess the functional flexibility of the brain. We aim to gain deeper understanding of the mechanisms underlying this technique and to predict the effects of stimulus frequency and intensity. For this purpose, a modified Jansen and Rit neural mass model (NMM) of a cortical circuit is used. This mean field model has been designed to strike a balance between mathematical simplicity and biological plausibility. We reproduced the entrainment phenomenon observed in EEG during a photic driving experiment. More generally, we demonstrate that such a single area model can already yield very complex dynamics, including chaos, for biologically plausible parameter ranges. We chart the entire parameter space by means of characteristic Lyapunov spectra and Kaplan-Yorke dimension as well as time series and power spectra. Rhythmic and chaotic brain states were found virtually next to each other, such that small parameter changes can give rise to switching from one to another. Strikingly, this characteristic pattern of unpredictability generated by the model was matched to the experimental data with reasonable accuracy. These findings confirm that the NMM is a useful model of brain dynamics during photic driving. In this context, it can be used to study the mechanisms of, for example, perception and epileptic seizure generation. In particular, it enabled us to make predictions regarding the stimulus amplitude in further experiments for improving the entrainment effect

Mieles del sistema serrano de Ventania: evaluación de la calidad microbiológica dentro del circuito de la planta de extracción Honeys from Ventania system: microbiological quality evaluation at different points of honey-processing

La miel es un producto natural que presenta una carga microbiana muy baja. No obstante, durante el procesamiento empleado para transformarla en un producto comercial, que incluye una etapa de extracción, puede contaminarse. El objetivo de este trabajo fue evaluar la contaminación microbiológica en diferentes puntos del circuito dentro de las plantas de extracción de miel. En 50 muestras se cuantificó el número de hongos filamentosos y levaduras, así como el de coliformes totales, y se determinó la presencia de Salmonella spp. Todas las muestras provenientes de los panales y de los extractores centrífugos presentaron un recuento de hongos filamentosos y levaduras &#8804; 10 UFC/g de miel, y ausencia de coliformes. Sin embargo, se evidenciaron problemas de contaminación en la etapa de separación cera-miel de los opérculos, con indicios de que el sistema "en frío" implicaría mayores riesgos. De un total de 30 muestras procedentes de la bomba o de los tambores, 4 presentaron recuentos de hongos filamentosos y levaduras entre 10 y 50 UFC/g de miel. El presente trabajo muestra la importancia de prevenir contaminaciones provenientes de la separadora cera-miel y también la necesidad de realizar estudios microbiológicos en las plantas de extracción, ya que éstos podrían contribuir a determinar los puntos críticos en los sistemas de control de calidad.One stage of honey production is extraction. Honey is a product with minimal types and levels of microorganisms; however it could be contaminated during its manipulation. The aim of this work was to evaluate the microbiological contamination of honey at different processing points. Mould and yeast, total coliform number as well as the presence of Salmonella spp. were determined in 50 samples. All comb and centrifugal honey-extractor samples showed low levels of mould and yeast (&#8804;10 CFU/g of honey) and an absence of total coliforms. Contamination problems were observed at the uncapping stage of beeswax-capped honey separation, showing that the "unheated" honey process would imply more risks. Ten to fifty CFU/g of honey of mould and yeast were observed in four out of 30 samples from the honey pump and drums. The present work shows the importance of preventing contamination at the beeswax-honey separation stage, and also highlights the need to perform microbiological studies in the honeyhouse, which would contribute to determine critical points in control quality systems

Gas barrier and adhesion of interpenetrating polymer networks based on poly(diurethane bismethacrylate) and different epoxy–amine networks

International audienceno abstrac

Mieles de la región periserrana del Sistema de Ventania, Argentina

Las características de una miel están estrechamente relacionadas con su origen botánico y geográfico. Veintidós muestras de miel correspondientes a la cosecha 1996-97, provenientes de la región de llanura que cir-cunda al cordón de las sierras australes de la provincia de Buenos Aires, denominado Sistema de Ventania, fueron analizadas para estudiar sus características polínicas y fisico-químicas. Se identificaron 44 tipos morfológi-cos de polen que fueron determinados a nivel del taxón más próximo. Los resultados obtenidos indicaron que 15 muestras fueron monoflorales, siendo 12 de Eucalyptus sp. (E. camaldulensis, E. viminalis) y tres de Diplotaxis tenuifolia, en tanto que las siete muestras restantes fueron de origen floral mixto. Las familias más representadas fueron: Asteraceac, Brassicaceae, Chenopodiaceae-Amaranthaceae, Fabaceae, Myrtaceac y Poacea

The effects of pasteurisation on albumin: an EPR binding assay for polymeric albumin.

The ability of a nitroxyl fatty acid (NFA) to bind specifically to albumin is abolished when, in the absence of stabilizers, a 4% solution of this protein is heated above a critical temperature of 60 degrees C. This treatment leads to the formation of "albumin polymers" as classically evidenced by GPC. Since the bound fraction is evidenced in EPR spectroscopy by a large anisotropic component, the presence of this anisotropy can be used in the assessment of the quality of the pharmaceutical preparations of albumin, which are usually pasteurized in order to inactivate viruses. Moreover, in sharp contrast with the behavior of albumin dispersions, lyophilised albumin subjected to heat treatment at 70 degrees C for 24 h left the protein untouched regarding its NFA binding and GPC profile