Synthesis of functionalized gold nanoparticles capped with 3-mercapto-1-propansulfonate and 1-thioglucose mixed thiols and "in vitro" bioresponse.

The synthesis, characterization and assessment of biological behavior of innovative negatively charged functionalized gold nanoparticles is herein reported, for potential applications in the field of radiotherapy and drug delivery. Gold nanoparticles (AuNPs) functionalized with two capping agents, i.e., the 3-mercapto-1-propansulfonate (3-MPS) and 1-ß-thio-D-glucose (TG), have been on purpose synthesized and fully characterized. Advanced characterization techniques including X-Ray Photoelectron Spectroscopy (XPS) were applied to probe the chemical structure of the synthesized nanomaterials. Z-potential and Dynamic Light Scattering measurements allowed assessing the nanodimension, dispersity, surface charge and stability of AuNPs. Transmission Electron Microscopy (TEM) and Flame Atomic Absorption Spectroscopy (FAAS) were applied to the "in vitro" HSG cell model, to investigate the nanoparticles-cells interaction and to evaluate the internalization efficiency, whereas short term cytotoxicity and long term cell killing were evaluated by means of MTT and SRB assays, respectively. In conclusion, in order to increase the amount of gold atoms inside the cell we have optimized the synthesis for a new kind of biocompatible and very stable negatively charged TG-functionalized nanoparticles, with diameters in a range that maximize the uptake in cells (i.e., ∼15nm). Such particles are very promising for radiotherapy and drug delivery application.

Bioconjugation of gold-polymer core-shell nanoparticles with bovine serum amine oxidase for biomedical applications.

Core-shell gold nanoparticles [AuNPs], stabilized with a hydrophilic polymer, poly(3-dimethylammonium-1-propyne hydrochloride) [PDMPAHCl], have been used for the immobilization of bovine serum amine oxidase [BSAO]. The functionalized surface of the hybrid nanoparticles is pH responsive, due to the presence of aminic groups that carry out a double role: on one hand they act as ligands for the gold nanoparticle surface, allowing the colloidal stabilization and, on the other hand, they give a hydrophilic characteristic to the whole colloidal suspension. The core-shell nanoparticles [Au@PDMPAHCl] have been characterized by using UV-vis and X-ray photoelectron spectroscopy, DLS, ζ-potential measurements and by FE-TEM microscopy. BSAO enzyme can be loaded by non-covalent immobilization onto Au@PDMPAHCl nanoparticles up to 70% in weight, depending on the pH values of the environmental medium. Activity tests on Au@PDMPAHCl-BSAO bioconjugates confirm an enzymatic activity up to 40%, with respect to the free enzyme activity. Moreover, our results show that loading and enzymatic activity are rather interrelated characteristics and that, under appropriate polymer concentration and pH conditions, a satisfactory compromise can be reached. These results, as a whole, indicate that Au@PDMPAHCl-BSAO bioconjugate systems are promising for future biomedical applications.

Silver nanoparticles linked by a Pt-containing organometallic dithiol bridge: study of local structure and interface by XAFS and SR-XPS.

Silver nanoparticles (AgNPs) functionalized with an organometallic bifunctional thiol containing Pt(ii) centers, generated in situ from trans-trans-[thioacetyl-bistributylphosphine-diethynylbiphenyl-diplatinum(ii)], were synthesized with different sulphur/metal molar ratios (i.e. AgNPs-1 and AgNPs-2) with the aim to obtain nanosystems of different mean size and self-organization behaviour. AgNPs spontaneously self-assemble, giving rise to 2D networks, as previously assessed. In this work a deeper insight into the chemico-physical properties of these AgNPs is proposed by means of synchrotron radiation induced X-ray photoelectron spectroscopy (SR-XPS) and X-ray absorption fine structure spectroscopy (XAFS) techniques. The results are discussed in order to probe the interaction at the interface between a noble metal and a thiol ligand at the atomic level and the aim of this study is to shed light on the chemical structure and self-organization details of nanosystems. The nature of the chemical interaction between the dithiol ligand and the Ag atoms on the nanoparticle surface was investigated by combining SR-XPS (S2p, Ag3d core levels) and XAS (S and Ag K-edges) analysis. UV-visible absorption and emission measurements were also carried out on all samples and compared with TD-DFT calculations so as to get a better understanding of their optical behavior and establish the nature of the excitation and emission processes.

Gold nanoparticles and gold nanoparticle-conjugates for delivery of therapeutic molecules. Progress and challenges.

This article reviews the most recent literature data on the applications of gold nanoparticles and their various conjugates which make them suitable structures towards biomedical and clinical purposes, with an emphasis on their use as drug delivery vehicles for selective targeting of cancer cells. With the rapid surge in the development of nanomaterials, new methodologies and treatment strategies have been explored and these topics should be taken into consideration when a current scenario is required in the design of new experimental approaches or in a comprehensive data interpretation. We present here a summary of the main properties of gold nanoparticles and their conjugates and the state-of-the-art of non-conventional treatment in targeted drug delivery based on gold nanoparticles as carriers, with the aim to give the reader an overview of the most significant advances in this field.

Dielectric relaxations of ionic thiol-coated noble metal nanoparticles in aqueous solutions: electrical characterization of the interface.

The radiowave dielectric properties of organothiol monolayer-protected Au and Ag metallic nanoparticles have been investigated in the frequency range of 10 kHz to 2 GHz, where a dielectric relaxation, due to the polarization of the ionic atmosphere at the aqueous interface, occurs. The simultaneous measurement of the particle size, by means of dynamic light scattering technique, and of the particle electrical charge, by means of laser microelectrophoresis technique, allow us to describe the whole dielectric behavior at the light of the standard electrokinetic model for charged colloidal particles. Au and Ag metallic nanoparticles experience a large charge renormalization, in agreement with the counterion condensation effect for charged spherical colloidal particles. The value of the effective valence Z(eff) of each nanoparticle investigated has been evaluated thanks to the dielectric parameters of the observed relaxation process and further confirmed by direct current electrical conductivity measurements. All in all, these results provide support for the characterization of the electrical interfacial properties of metallic nanoparticles by means of dielectric relaxation measurements.

Tetracycline residues in royal jelly and honey by liquid chromatography tandem mass spectrometry: validation study according to Commission Decision 2002/657/EC.

A specific, sensitive and robust liquid chromatography tandem mass spectrometry method for determining oxytetracycline, tetracycline, chlortetracycline and doxycycline in royal jelly and honey samples is presented. Extraction of drug residues was performed by ammonium acetate buffer as extractant followed by a clean-up with metal chelate affinity chromatography and solid-phase extraction. Tetracycline analysis was performed using liquid chromatography-electrospray ionisation-tandem mass spectrometry. The presented method is the first validated for royal jelly and in accordance with the requirements set by Commission Decision 2002/657/EC. Recoveries of the methods, calculated spiking the samples at 5.0, 10.0, 20.0 and 30.0 µg kg(-1), were 79% to 90% for honey and 77% to 90% for royal jelly. The intra-day precision (RSD) ranged between 8.1% and 15.0% for honey and from 9.1% to 16.3% for royal jelly, while inter-day precision values were from 10.2% to 17.6% and from 10.6% to 18.4% respectively for honey and royal jelly. Linearity for the four analytes was calculated from 5.0 to 50.0 µg kg(-1). The decision limits (CCα) ranged from 6.2 to 6.4 µg kg(-1) and from 6.1 to 6.5 µg kg(-1) for honey and royal jelly, respectively. Detection capabilities values (CCß) ranged between 7.2 and 7.7 µg kg(-1) and from 7.3 to 7.9 µg kg(-1) respectively for honey and royal jelly. The developed method is currently in use for confirmation of the official control analysis of honey and royal jelly samples.

High-energy angle resolved reflection spectroscopy on three-dimensional photonic crystals of self-organized polymeric nanospheres.

We report on the optical characterization of three-dimensional opal-like photonic crystals made by self-organized nanospheres of poly[styrene-(co-2-hydroxyethyl methacrylate)] having a face centred cubic (fcc) structure oriented along the [111] direction. A detailed optical characterization of the samples is presented using angle resolved reflection spectroscopy in specular geometry. The investigated energies are between a/lambda=0.5 and a/lambda=1.5 (where a is the lattice parameter and lambda is the light wavelength), a region in which both first and second-order Bragg diffraction are expected. Some interesting features as branching of the Bragg peak dispersion and high energy reflection peaks are revealed. We compare the experimental data with theoretical calculations using both Bragg diffraction and band structure approach. A comparison with recent results reported in the literature is also presented.

[Air quality and human health: PM10 and respiratory diseases]. / Qualità dell'aria e salute: particolato atmosferico PM10 e malattie respiratorie.

In this paper a comparison between the air quality data collected in urban and rural areas is performed taking in account the PM10 levels allowed in the European Union and in the world and is related to the increase of respiratory diseases. The parameters considered are essentially due to the anthropogenic primary pollution: particulate matter PM10, benzene and toluene, CO and Polycyclic Aromatic Hydrocarbons.

[The historical-scientific foundations of thalassotherapy: state of the art]. / Le basi storico-scientifiche della talassoterapia: stato dell'arte.

Throughout the ages the interest in the use of sea water in medicine has fluctuated from century to century and from nation to nation. In this paper, the historical development of sea medicine from the ancient Egyptians until the 20th century is given. The medical world has viewed it with different opinions, from very enthusiastic to extremely critical, and from beneficial to harmful. In the last decades, thalassotherapy is receiving renewed attention from many medical specialties and health tourists. The aim of this review is that of offer an update on the real therapeutic possibility of the thalassotherapy. However, the exact therapeutic potential of thalassotherapy still remains largely unknown. Better and more profound scientific evidence for its efficacy is therefore warranted, in particular for its effects on the musculoskeletal system and skin. The main researches belong to the activity of thalassotherapy and the clinic outcomes, namely in osteoarthritis patients, were referred.

Chiral separation of methoxamine and lobeline in capillary zone electrophoresis using ethylbenzene-deactivated fused-silica capillary columns and cyclodextrins as buffer additives.

The complete chiral separation of methoxamine and lobeline was achieved by capillary zone electrophoresis on an ethylbenzene-deactivated fused-silica capillary column and with cyclodextrins (CDs) as buffer additives. Among the CDs investigated in this study, i.e. alpha-CD, beta-CD, dimethyl-beta-CD, hydroxypropyl-beta-CD and gamma-CD, all the three beta-type CDs showed chiral recognition on the two drugs investigated. Under the investigated conditions, the baseline chiral separation of methoxamine can be achieved with 90 mM Tris-H3PO4 (pH 2.5) containing 11.5 mM of the three beta-type CDs, with dimethyl-beta-CD giving the best resolution, whereas the baseline chiral separation of lobeline can be realized by using 90 mM Tris-H3PO4 buffer (pH 2.5) containing 5.8 mM dimethyl-beta-CD or 29.5 mM hydroxypropyl-beta-CD.

Characterisation of fatty acids in drying oils used in paintings on canvas by GC and GC-MS analysis.

Of the various binding media used in paintings, this work examines drying oils. During the initial phase of polymerisation and the progressive ageing process, the fraction of unsaturated and polyunsaturated fatty acids undergoes various changes (reticulation, oxidation, etc.), that give rise to characteristic compounds. Within a broader research project, aimed at the characterisation of binding media, a preliminary study was made of the ageing process of linseed oil. In this regard, linseed oil was spread on a glass or canvas support and then dried in the open air. The ageing of the spread linseed oil was monitored by taking samples of the material at regular intervals. After the fatty acids had changed into methylesters, the samples were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results obtained have been reported as a ratio between the areas of the chromatographic peaks of the different fatty acids found.

Hydrophobic-phase-modified fused-silica columns for capillary electrophoresis.

Coated capillaries modified with a hydrophobic layer were developed. Linear hydrocarbons and ethylbenzene modified surfaces greatly improved the electrophoretic performance of the capillaries. The column efficiency for organic compounds reached as high as 327 000 theoretical plate numbers per meter on a 50 microm I.D. linear hydrocarbon (C6) surface treated fused-silica capillary column. This value did not change during 50 repeated analyses and the columns showed strong stability against 0.1 M NaOH and 0.1 M HCl. The relative standard deviation of the run-to-run, day-to-day, and capillary-to-capillary coating with hydrophobic layer showed values of < or =2.5%, and good reproducibility. The separations of four aromatic amines and six pharmacological amines at pH 2.5 is reported.

Some applications of ligand-exchange--I. Recovery of phenolic compounds from water.

The properties of a chelating ion-exchanger in the iron(III) form in contact with an aqueous solution containing phenolic compounds have been studied. The phenols retained are completely displaced by elution with an ethanolic sodium hydroxide solution.

Determination of organophosphorus pesticides by thin-layer chromatography.

Analysis for 13 common organophosphorus pesticides by thin-layer chromatography is described; 17 solvent systems were examined. With channel thin-layer chromatography, linear calibration graphs were obtained for the range 1-10 mug.