On the use of 2,1,3-benzothiadiazole derivatives as selective live cell fluorescence imaging probes

Newly designed 2,1,3-benzothiadiazole-containing fluorescent probes with four excited state intramolecular proton transfer (ESIPT) sites were successfully tested in live cell-imaging assays using a confluent monolayer of human stem-cells (tissue). All tested dyes were compared with the commercially available DAPI and gave far better results. (c) 2010 Elsevier Ltd. All rights reserved.

Iron oxyhydroxide nanostructured in montmorillonite clays: Preparation and characterization

Akaganeite is a very rare iron oxyhydroxide in nature. It can be obtained by many synthetic routes, but thermohydrolysis is the most common method reported in the literature. In this work, akaganeite-like materials were prepared through the thermohydrolysis of FeCl(3)center dot 6H(2)O in water and suspensions containing clay minerals. X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) data show that the clays determine the crystal phase and size of the iron oxyhydroxide crystals. According to XRD and FTIR data, beta-FeO(OH) (akaganeite) is the main metal oxyhydroxide phase. Considering the small basal spacing (d(0 0 1)) displacement observed when comparing the XRD patterns of pristine clays with the composites containing beta-FeO(OH), the iron oxyhydroxide should be mostly located on the basal and edge surfaces of the clay minerals. UV-Vis electronic absorption spectra indicate that the preferred phase of the iron oxyhydroxide is determined by the nature of the clay minerals. (C) 2010 Elsevier Inc. All rights reserved.

Raman spectra of a pseudo-oxocarbon anion in ionic liquids

Raman and electronic spectra of the [3,5-bis(dicyanomethylene)cyclopentane-1,2,4-trionate] dianion, the croconate violet (CV), are reported in solutions of ionic liquids based on imidazolium cations. Different normal modes of the CV anion, nu (C=O), nu (CO) + nu (CC) + nu (CCN), and nu(C N), were used as probes of solvation characteristics of ionic liquids, and were compared with spectra of CV in common solvents. The spectra of CV in ionic liquids are similar to those in dichloromethane solution, but distinct from those in protic solvents such as ethanol or water. The UV-vis spectra of CV in ionic liquids strongly suggest pi-pi interactions between the CV anion and the imidazolium cation. Copyright (C) 2009 John Wiley & Sons, Ltd.

Amperometric detection of benzoyl peroxide in pharmaceutical preparations using carbon paste electrodes with peroxidases naturally immobilized on coconut fibers

This paper describes the applications of anew carbon paste electrode containing fibers of coconut (Cocus nucifera L) fruit, which are very rich in peroxidase enzymes naturally immobilized on its structure. The new sensor was applied for the amperometric quantification of benzoyl peroxide in facial creams and dermatological shampoos. The amperometric measurements were performed in 0.1 mol L(-1) phosphate buffer (pH 5.2), at 0.0 V (versus Ag/AgCl). On these conditions, benzoyl peroxide was rapidly determined in the 5.0-55 mu mol L(-1), with a detection limit of 2.5 mu mol L(-1) (s/n = 3), response time of 4.1 s (90% of the steady state) and sensitivity limit of 0.33 A mol L(-1) cm(-2). The amperometric results are in good agreement with those obtained by spectrophotometric technique, used as a standard method. (C) 2009 Elsevier B.V. All rights reserved.

Cytotoxicity and antiangiogenic activity of grandisin

Objectives The antitumoural properties of grandisin, a tetrahydrofuran neolignan from Piper solmsianum, were investigated by in-vitro and in-vivo assays using the Ehrlich ascites tumoural (EAT) model. Methods Viability of the tumour cells was evaluated by Trypan blue exclusion and MTT methods, after incubation with grandisin (0.017-2.3 mu M). The effects of grandisin on the activity of caspase-3, -6, -8, and -9 were also investigated using colorimetric protease kits. In-vivo studies were performed in EAT-bearing mice treated intraperitoneally with 2.5, 5 or 10 mg/kg grandisin for 10 days. Key findings Grandisin inhibited the growth of EAT cells, by both methods, with IC50 values less than 0.25 mu M. The results showed that the activity of all the caspases studied increased in grandisin-treated cells, when compared with control, non-treated cells. Administering grandisin to EAT-bearing mice increased survival of the animals, in a dose-dependent manner. Simultaneously, we detected a 66.35% reduction of intraperitoneal tumour cell burden in the animals treated with 10 mg/kg grandisin. Additionally, in these animals, the marked increase of vascular endothelial growth factor (VEGF) levels, induced by EAT development, was decreased with treatment with grandisin, resulting in a reduction of 32.1% of VEGF levels in the peritoneal washing supernatant, when compared with the control. Conclusions The results demonstrated that grandisin induced in-vitro cytotoxicity and antiangiogenic effects in mice while it acted against tumour evolution, prolonging host survival.

On the energy transfer from a polymer host to the rhenium(I) complex in OLEDs

Photoluminescence and electroluminescence of PVK films doped with fac-[ClRe(CO)(3)(bpy)], bpy=2,2`-bipyridine, are investigated. Photoluminescence spectra of spin-coated PVK films (lambda(exc)=290 nm) exhibit a broad band centered at 405 nm. As the concentration of dopant increases, the polymer emission is quenched and a band at 555 nm appears (isosbestic point at 475 nm). In OLEDs with ITO/PEDOT:PSS/PVK/butylPBD/Al architecture doped with fac-[ClRe(CO)(3)(bpy)], the polymer host emission is completely quenched even at the lowest concentration of dopant. The electroluminescence spectra of the devices show that there is an efficient energy transfer from the host to the dopant, which exhibits a very intense emission at 580 nm. (C) 2009 Elsevier B.V. All rights reserved.

V(2)O(5) nanoparticles obtained from a synthetic bariandite-like vanadium oxide: Synthesis, characterization and electrochemical behavior in an ionic liquid

Highly stable and crystalline V(2)O(5) nanoparticles with an average diameter of 15 nm have been easily prepared by thermal treatment of a bariandite-like vanadium oxide, V(10)O(24)center dot 9H(2)O. Their characterization was carried out by powder X-ray diffractometry (XRD). Fourier transform infrared (FT-IR) and Raman spectroscopies, and transmission electron microscopy (TEM). The fibrous and nanostructured film obtained by electrophoretic deposition of the V(2)O(5) nanoparticles showed good electroactivity when submitted to cyclic voltammetry in an ionic liquid-based electrolyte. The use of this film for the preparation of a nanostructured electrode led to an improvement of about 50% in discharge capacity values when compared with similar electrodes obtained by casting of a V(2)O(5) xerogel. (C) 2009 Elsevier Inc. All rights reserved.

In vitro basal cytotoxicity assay applied to estimate acute oral systemic toxicity of grandisin and its major metabolite

Preclinical investigations can start with preliminary in vitro studies before using animal models. Following this approach, the number of animals used in preclinical acute toxicity testing can be reduced. In this study, we employed an in-house validated in vitro cytotoxicity test based on the Spielmann approach for toxicity evaluation of the lignan grandisin, a candidate anticancer agent, and its major metabolite. the 4-O-demethylgrandisin, by neutral red uptake (NRU) assay, on mouse fibroblasts Balb/c 3T3 cell line. Using different concentrations of grandisin and its major metabolite (2.31; 1.16; 0.58; 0.29; 0.14; 0.07; 0.04; 0.002 mu M) in Balb/c 3T3-A31 NRU cytotoxicity assay, after incubation for 48 h, we obtained IC(50) values for grandisin and its metabolite of 0.078 and 0.043 mu M, respectively. The computed LD(50) of grandisin and 4-O-demethylgrandisin were 617.72 and 429.95 mg/kg, respectively. Both were classified under the Globally Harmonized System as category 4. Since pharmacological and toxicological data are crucial in the developmental stages of drug discovery, using an in vitro assay we demonstrated that grandisin and its metabolite exhibit distinct toxicity profiles. Furthermore, results presented in this work can contribute to reduce the number of animals required in subsequent pharmacological/toxicological studies. (C) 2010 Elsevier GmbH. All rights reserved.

Thionicotinamide SAM on Gold: Adsorption Studies and Electroactivity

STM and impedance results of the self-assembled monolayer (SAM) formed with thionicotinamide (TNA) on gold indicate the presence of defects that increase with the immersion time of the electrode in the TNA solution affecting the SAM electroactivity toward the electron transfer reaction of the cytochrome e metalloprotein and [Fe(CN)(6)](4-) and [Ru(NH(3))(6)](3+) complexes. It was observed that this electroactivity was also affected by the pH of the electrolyte solution. SERS and STM data indicate sulfur coordination to the surface with contribution of the NH(2) group. From the dependence of the TNA surface coverage on the temperature and concentration in solution, thermodynamic parameters of adsorption were determined.

Ruthenium nanoparticles prepared from ruthenium dioxide precursor: Highly active catalyst for hydrogenation of arenes under mild conditions

The hydrogenation of benzene and benzene derivatives was studied using Ru(0) nanoparticles prepared by a very simple method based on the in situ reduction of the commercially available precursor ruthenium dioxide under mild conditions (75 degrees C and hydrogen pressure 4atm) in imidazolium ionic liquids. Total turnovers (TTO) of 2700 mol/mol Ru were obtained for the conversion of benzene to cyclohexane under solventless conditions and TTO of 1200 mol/mol Ru were observed under ionic liquid biphasic conditions. When corrected for exposed ruthenium atoms, TTO values of 7940 (solventless) and 3530 (biphasic) were calculated for benzene hydrogenation. These reaction rates are higher than those observed for Ru nanoparticles prepared from decomposition of an organometallic precursor in similar conditions. The presence of the partially hydrogenated product cyclohexene was also detected at low conversion rates. (C) 2008 Elsevier B.V. All rights reserved.

Coating of Cotton Yarn with Poly(vinyl alcohol) and Poly(N-vinyl-2-pyrrolidone) Crosslinked via Ultraviolet Radiation

The coating of cotton fiber is used in the textile industry to increase the mechanical resistance of the yarn and their resistance to vibration, friction, impact, and elongation, which are some of the forces to which the yarn is subjected during the weaving process. The main objective of this study was to investigate the use of synthetic hydrophilic polymers, poly(vinyl alcohol) (PVA), and poly(N-vinyl-2-pyrrolidone) (PVP) to coat 100% cotton textile fiber, with the aim of giving the fiber temporary mechanical resistance. For the fixation of the polymer on the fiber, UV-C radiation was used as the crosslinking process. The influence of the crosslinking process was determined through tensile testing of the coated fibers. The results indicated that UV-C radiation increased the mechanical resistance of the yarn coated with PVP by up to 44% and the yarn coated with PVA by up to 67% compared with the pure cotton yarn, that is, without polymeric coating and crosslinking. This study is of great relevance, and it is important to consider that UV-C radiation dispenses with the use of chemical substances and prevents the generation of toxic waste at the end of the process. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2560-2567, 2011

Chemoprotective effect of the tetrahydrofuran lignan grandisin in the in-vivo rodent micronucleus assay

Objectives The chemoprotective effect of the tetrahydrofuran lignan grandisin against DNA damage induced by cyclophosphamide (200 mg/kg) has been evaluated using the in vitro rodent micronucleus assay. Methods The effects of a daily oral administration of grandisin (2, 4, or 8 mg/kg) for five days before exposure to cyclophosphamide on the frequency of micronucleus in the bone marrow of normal mice exposed and unexposed to cyclophosphamide were investigated (n = 5 per group). Electrochemical measurements were applied to investigate whether the antimutagenic effects of grandisin could be, at least in part, a consequence of its or its metabolite`s antioxidant properties. Key findings Grandisin did not show mutagenic effects on the bone marrow cells of exposed mice. On the other hand, the oral administration of grandisin (2, 4, or 8 mg/kg) per day reduced dose-dependently the frequency of micronucleus, induced by cyclophosphamide, in all groups studied. Cyclic voltammograms showed two peaks for a grandisin metabolite, which were absent for grandisin. Conclusions Under the conditions tested herein, this study has shown that mice treated with grandisin presented, in a dose-dependent manner, a protective effect against cyclophosphamide-induced mutagenicity. This effect could be, at least in part, associated to grandisin bioactivation. These data open new perspectives for further investigation into the toxicology and applied pharmacology of grandisin.

Crosslinking of Poly(N-vinyl-2-pyrrolidone) in the Coating of Cotton Yarn

Coating of cotton yarn is employed in the textile industry to increase the mechanical resistance of the yarns and resistance to vibration, friction, impact, and elongation, which are some of the forces to which the yarn is subjected during the weaving process. The main objective of this study is to investigate the usage of a synthetic hydrophilic polymer, poly(N-vinyl-2-pyrrolidone) (PVP), to coat 100% cotton textile yarn, aiming to give the yarn a temporary mechanical resistance. For the improvement of the mechanical resistance of the yarn, the following crosslinking processes of PVP were investigated: UV-C (ultraviolet) radiation, the Fenton and photo-Fenton reactions, and sensitized UV-C radiation. The influence of each crosslinking process was determined through tensile testing of the coated yarns. The results indicated that the best crosslinking process employed was UV-C radiation; increasing the mechanical resistance of the yarn up to 44% if compared with the pure cotton yarn, that is, without polymeric coating and crosslinking. POLYM. ENG. SCI., 51:445-453, 2011. (C) 2010 Society of Plastics Engineers

Raman spectra of acetonitrile in imidazolium ionic liquids

Raman spectra of dilute solutions of acetonitrile in ionic liquids reveal the characteristic features of ionic liquids` polarity. This is accomplished by investigating the Raman bandshape of the nu (CN) band, corresponding to the CN stretching mode of CH(3)CN, which is a very sensitive probe of the local environment. The amphiphilic nature of the CH(3)CN molecule allows us to observe the effect of electron pair acceptor and electron pair donor characteristics on ionic liquids. It has been found that the overall polarity of nine different ionic liquids based on 1-alkyl-3-methylimidazolium cations is more dependent on the anion than cation. The observed wavenumber shift of the nu (CN) band of CH(3)CN in ionic liquids containing alkylsulfate anions agrees with the significant different values previously measured for the dielectric constant of these ionic liquids. The conclusions obtained from the analysis of the nu (CN) band were corroborated by the analysis of the symmetric nu(1) (CD(3)) stretching mode of deuterated acetonitrile in different ionic liquids. Copyright (C) 2010 John Wiley & Sons, Ltd.

NUCEL (Cell and Molecular Therapy Center): A multidisciplinary center for translational research in Brazil

Social and economical development is closely associated with technological innovation and a well-developed biotechnological industry. In the last few years, Brazil`s scientific production has been steadily increasing; however, the number of patents is lagging behind, with technological and translational research requiring governmental incentive and reinforcement. The Cell and Molecular Therapy Center (NUCEL) was created to develop activities in the translational research field, addressing concrete problems found in biomedical and veterinary areas and actively searching for solutions by employing a genetic engineering approach to generate cell lines over-expressing recombinant proteins to be transferred to local biotech companies, aiming at furthering the development of a national competence for local production of biopharmaceuticals of widespread use and of life-saving importance. To this end, mammalian cell engineering technologies were used to generate cell lines over-expressing several different recombinant proteins of biomedical and biotechnological interest, namely, recombinant human Amylin/IAPP for diabetes treatment, human FVIII and FIX clotting factors for hemophilia, human and bovine FSH for fertility and reproduction, and human bone repair proteins (BMPs). Expression of some of these proteins is also being sought with the baculovirus/insect cell system (BEVS) which, in many cases, is able to deliver high-yield production of recombinant proteins with biological activity comparable to that of mammalian systems, but in a much more cost-effective manner. Transfer of some of these recombinant products to local Biotech companies has been pursued by taking advantage of the Sao Paulo State Foundation (FAPESP) and Federal Government (FINEP, CNPq) incentives for joint Research Development and Innovation partnership projects.