Cito y Genotoxicidad de partículas SiO2@ZrO2 en células de osteosarcoma humano

El óxido de circonio (ZrO2) es un material con importantes aplicaciones biomédicas. La formación de partículas núcleo@cáscara (núcleo de un material y cáscara de otro) y su uso en sistemas de liberación controlada de drogas están en el foco del interés científico actual. Sin embargo, poco se sabe sobre su toxicidad. Aquí investigamos la cito y genotoxicidad de esferas SiO2@ZrO2 con cáscara cristalina (SiO2@ZrO2c) y con cáscara amorfa (SiO2@ZrO2a) en células de osteosarcoma humano en cultivo (MG-63) expuestas a un rango de 5-100 µg/ml por 24 h. Según microscopía electrónica de transmisión, ambos tipos de partículas cruzan la membrana celular y se alojan en vesículas en el citoplasma. La viabilidad celular (ensayo MTT) disminuyó sólo en células expuestas a 100 µg/ml de SiO2@ZrO2c (p<0,001). Asimismo, los primeros efectos genotóxicos se observaron a 5 µg/ml de SiO2@ZrO2c y 10 µg/ml de SiO2@ZrO2a con el daño sobre el ADN celular (ensayo Cometa). Al incrementar la concentración de SiO2@ZrO2c a 25 µg/ml y de SiO2@ZrO2a a 50 µg/ml se produjo un aumento de la frecuencia de micronúcleos (p<0,05). Por otro lado, ambos tipos de partículas provocaron a partir de 50 µg/ml una disminución de la relación GSH/GSSG (p<0,001), pero sólo SiO2@ZrO2c a 100 µg/ml produjo un aumento significativo de las especies reactivas de oxígeno (p<0,01). Pudo concluirse que solo SiO2@ZrO2c reduce la viabilidad celular asociada a un aumento en estrés oxidativo, sin embargo ambos materiales causan daño en el ADN indicando una cito y genotoxicidad dependiente del ordenamiento atómico en la cáscara.Fil: Di Virgilio, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Maisuls, Iván. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Tecnología de Recursos Minerales y Ceramica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Tecnología de Recursos Minerales y Ceramica; Argentina. Universidad Nacional de la Plata. Facultad de Cs.exactas. Departamento de Cs.biológicas. Cátedra Bioquímica Patologica; ArgentinaFil: Arnal, Pablo Maximiliano. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Tecnología de Recursos Minerales y Ceramica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Tecnología de Recursos Minerales y Ceramica; Argentin

Real time system applied to the somatosensorial quantitative thermotest

This work is a real time application for a painless and bloodless analysis of the peripheral nervous system in patients with sensorial disorders due to affections in their thin myelinized fibers and their amyelinic fibers. The Somatosensorial Quantitative Thermotest is an ideal method for this evaluation, since it allows not only to quantify sensorial deficit, but also to value positive sensorial phenomena. The system integrates hardware and software and works based on a battery of tests which, by means of controlled stimuli measure the patient's answer to heat and cold. It should be noticed that these stimuli can be adapted in order to carry out a more accurate diagnosis. Both hardware and software have been specially designed for this application. This permits to control stimuli generation in real time, which reduces sensorial thresholds appreciation errors.Sistemas Distribuidos - Redes Concurrencia - Sesión de póstersRed de Universidades con Carreras en Informática (RedUNCI

Diffusion aluminide coatings for hot corrosion and oxidation protection of nickel-based superalloys. Effect of fluoride-based activator salts

The influence of two different fluoride-based activator salts (NH4F and AlF3) was studied for diffusion aluminide coatings obtained via pack cementation on a Ni-based superalloy (René 108DS). The resistance to oxidation and hot corrosion was assessed as a function of the concentration of activator salts used during the synthesis process by means of pack cementation. Two different concentrations were selected for activator salts (respecting the equimolarity of fluoride in the synthesis) and the obtained diffusion coatings were compared in terms of morphology, thickness and composition, as well as in terms of microstructural evolution after high temperature exposure. Isothermal oxidation tests were conducted at 1050 C in air for 100 h in a tubular furnace. The oxidation kinetics were evaluated by measuring the weight variation with exposure time. The microstructural evolution induced by the high temperature exposure was investigated by SEM microscopy, EDS analysis and X-ray diffraction. Results showed that the coatings obtained with AlF3 activator salt are thicker than those obtained using NH4F as a consequence of different growth mechanism during pack-cementation. Despite this evidence, it was found that the NH4F coatings show a better oxidation resistance, both in terms of total mass gain and of quality of the microstructure of the thermally grown oxide. On the other hand, coatings produced with high concentration of AlF3 exhibited a better resistance in hot corrosion conditions, showing negligible mass variations after 200 h of high temperature exposure to aggressive NaCl and Na2SO4 salts

Vanadium, Ruthenium and Copper Compounds : A New Class of Nonplatinum Metallodrugs with Anticancer Activity

Cancer is a group of diseases involving abnormal cell growth. The cells grow uncontrollably with the potential to invade and spread to other parts of the body. This disease is one of the principal death causes in the world, thus becoming a significant topic of scientific research. On the other hand, transition metals play a fundamental role in different living systems. In particular, Metallodrugs represent new and powerful tools for diverse therapeutic applications. To date, various metallodrugs display interesting biological activities for chemotherapy. In this field, cisplatin was the first inorganic compound with high relevance in cancer treatment. This compound was a leader agent in clinical use. Toxicity and resistance problems trigger the development of other platinum drugs with better clinical perspective and also raise the scientific interest for the putative antitumor properties of V, Ru and Cu compounds. Several scientific articles show that complexes of these metals are the new metal-based drugs used in the treatment of several cancers, such us, lung, colon, breast, bladder, etc. In this review we recapitulate current information and new advances on antitumor in vitro effects of several organic and inorganic compounds derived from copper, ruthenium and vanadium. These metal derived compounds targeting DNA or cell proteins involved in cell signaling pathways related to cancer. The mechanisms of cell death of these metallodrugs have also been comprehensibly reviewed. The knowledge of these mechanisms of death and the relationship between chemical structure and biological activity may be useful for the design of new metal-based drugs with promising pharmacologic applications as anticancer agents.Centro de Química Inorgánic

Evaluation of antibacterial and cytotoxic effects of nano-sized bioactive glass/collagen composites releasing tetracycline hydrochloride

Aims: To evaluate the antibacterial efficacy of silicate bioactive glass nanoparticles/collagen composites functionalized with tetracycline hydrochloride (TCH). Methods and Results: Different concentrations of tetracycline hydrochloride (TCH) were incorporated on silicate bioactive glass nanoparticles/collagen composites by dipping these biomaterials for 48 h at 37°C in a solution of simulated body fluid (SBF) plus 0 05, 0 20 or 0 35 mg ml1 of the antibiotic. TCH release was assessed in double-distilled water at 37°C up to 72 h. The antibacterial activity of the samples has been evaluated in two ways: inhibition zone test and plate count method. The experiments were performed in vitro up to 48 h on four staphylococci strains (Staphylococcus aureus ATCC29213, ATCC25923, ATCC6538P and Staphylococcus epidermidis ATCC12228). The new composites were also tested for cytotoxicity on MG-63 human osteosarcoma cells. The results showed that the incorporation and release of TCH was dependent on the initial concentration of TCH in SBF. The biomaterials also inhibited the Staph. aureus cell growth even though the efficacy was similar for all concentration. On the other hand, no cytotoxic effects were found on osteoblast-like cells, even at the highest concentration. Conclusions: Considering all results, it can be concluded that the new composite acts as a suitable bioactive carrier of TCH and could have potential in the prevention of biomaterial related infections. Significance and Impact of the Study: The results suggest a potential application as wound dressing.Fil: Rivadeneira, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad Nacional de Salta; ArgentinaFil: Di Virgilio, Ana Laura. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Audisio, Marcela Carina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Boccaccini, A. R.. University of Erlangen-Nuremberg; AlemaniaFil: Gorustovich Alonso, Alejandro Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad Nacional de Salta; Argentin

Real time system applied to the somatosensorial quantitative thermotest

This work is a real time application for a painless and bloodless analysis of the peripheral nervous system in patients with sensorial disorders due to affections in their thin myelinized fibers and their amyelinic fibers. The Somatosensorial Quantitative Thermotest is an ideal method for this evaluation, since it allows not only to quantify sensorial deficit, but also to value positive sensorial phenomena. The system integrates hardware and software and works based on a battery of tests which, by means of controlled stimuli measure the patient's answer to heat and cold. It should be noticed that these stimuli can be adapted in order to carry out a more accurate diagnosis. Both hardware and software have been specially designed for this application. This permits to control stimuli generation in real time, which reduces sensorial thresholds appreciation errors.Sistemas Distribuidos - Redes Concurrencia - Sesión de póstersRed de Universidades con Carreras en Informática (RedUNCI

Copper complex with sulfamethazine and 2,2′-bipyridine supported on mesoporous silica microspheres improves its antitumor action toward human osteosarcoma cells: cyto- and genotoxic effects

Ideal drugs to cure cancer leave normal cells unharmed while selectively turning tumor cells unviable. Several copper complexes have been able to selectively slow down tumor proliferation. We hypothesized that Cu(smz)2(bipy)·H2O (1)—a copper-complex that has two ligands capable of interacting with DNA—would outperform Cu(smz)2(OH2)·2H2O (2), and also that supporting 1 on mesoporous silica spheres would decrease even further tumor cell viability in vitro. After exposing osteosarcoma cells (MG-63) and normal phenotype cells of bone origin (MC3T3-E1) to either complex, we studied their toxic effect and mechanisms of action. We determined cell viability (MTT assay) and quantified formation of reactive oxygen species (oxidation of DHR-123 to rhodamine). Moreover, we assessed genotoxicity from (i) formation of micronucleus (MN assay) and (ii) damage of DNA (Comet assay). After the exposure of 1 supported on silica spheres, we tested cell viability. Our results confirm our hypotheses: inhibition of tumor cells follows: supported 1 > dissolved 1 > 2. Future work that enhances the load of the complex exclusively in mesopores may improve the ability of 1 to further inhibit tumor cell viability.Fil: Cadavid Vargas, Juan Fernando. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Arnal, Pablo Maximiliano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Mojica Sepulveda, Ruth Dary. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Rizzo, Andrea. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Soria, Delia Beatriz. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Di Virgilio, Ana Laura. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

Crystal structure, Hirshfeld surface analysis, spectroscopic and biological studies on sulfamethazine and sulfaquinoxaline ternary complexes with 2,2′-biquinoline

Three ternary complexes of sulfaquinoxaline (SQO-4-amino-N-2-quinoxalinylbenzenesulfonamide) or sulfamethazine (SMT-4-amino-N-(4,6-dimethylpyrimidin-2-yl)-benzenesulfonamide) with Cu(ii) or Ni(ii) and 2,2′-biquinoline (BQ) as an auxiliary ligand have been studied. Their structures have been determined by single-crystal X-ray crystallography as Ni(SQO)2(BQ)·2H2O (I), Cu(SQO)(BQ)Cl·CH3OH (II) and Cu(SMT)(BQ)Cl (III). Compounds I and II crystallize in the triclinic space group P1 while complex III crystallizes in the monoclinic P21/c space group. The crystal lattice of all complexes is stabilized by the presence of diverse intermolecular interactions as verified by Hirshfeld surface analysis. Besides, electronic spectroscopies have also been used to characterize the compounds. The thermal behavior of the complexes was investigated by thermogravimetric and differential thermal analyses. Furthermore, the cytotoxic effect of the compounds has been tested against A549 (lung cancer) and MG-63 (human osteosarcoma) cell lines using the MTT methodology.Fil: Villa Perez, Cristian. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Cadavid Vargas, Juan Fernando. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Di Virgilio, Ana Laura. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Echeverría, Gustavo Alberto. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Camí, Gerardo Enrique. Universidad Nacional de Rosario; ArgentinaFil: Soria, Delia Beatriz. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentin

Crystal structure, Hirshfeld surface analysis, spectroscopic and biological studies on sulfamethazine and sulfaquinoxaline ternary complexes with 2,2′-biquinoline

Three ternary complexes of sulfaquinoxaline (SQO-4-amino-N-2-quinoxalinylbenzenesulfonamide) or sulfamethazine (SMT-4-amino-N-(4,6-dimethylpyrimidin-2-yl)-benzenesulfonamide) with Cu(ii) or Ni(ii) and 2,2′-biquinoline (BQ) as an auxiliary ligand have been studied. Their structures have been determined by single-crystal X-ray crystallography as Ni(SQO)2(BQ)·2H2O (I), Cu(SQO)(BQ)Cl·CH3OH (II) and Cu(SMT)(BQ)Cl (III). Compounds I and II crystallize in the triclinic space group P1 while complex III crystallizes in the monoclinic P21/c space group. The crystal lattice of all complexes is stabilized by the presence of diverse intermolecular interactions as verified by Hirshfeld surface analysis. Besides, electronic spectroscopies have also been used to characterize the compounds. The thermal behavior of the complexes was investigated by thermogravimetric and differential thermal analyses. Furthermore, the cytotoxic effect of the compounds has been tested against A549 (lung cancer) and MG-63 (human osteosarcoma) cell lines using the MTT methodology.Centro de Química InorgánicaInstituto de Física La Plat

Housing strategies of popular and middle class families residing in the Buenos Aires Metropolitan Area (Argentina)

El presente artículo analiza las diversas formas en las que las familias hacen frente a las difíciles condiciones de acceso al hábitat en la ciudad posfordista. Para ello, exploramos comparativamente las estrategias habitacionales implementadas por familias de sectores populares y medios residentes en el área metropolitana de Buenos Aires (Argentina). La selección de familias de sectores populares y medios responde al interés por analizar los efectos que tiene la posición en la estructura de clases en las acciones desarrolladas por las familias para su reproducción. Desde esta perspectiva, la lógica, las decisiones y los objetivos que guían el acceso al hábitat y los recursos que se movilizan varían según la posición que ocupan las familias en la estructura de clases. En este trabajo se avanza en el análisis de las estrategias habitacionales, haciendo hincapié en las diferencias y las similitudes que se observan entre grupos sociales que ocupan posiciones diferenciales en dicha estructura pero habitan en localizaciones próximas en la ciudad, y entre grupos sociales que ocupan posiciones similares en la producción y en el consumo, pero que residen en distintas áreas y/o localizaciones en el espacio urbano.This article analyzes the various ways in which families face difficult habitat access conditions in the post-Fordist city. In order to do this, we have comparatively explored the housing strategies implemented by popular and middle class families residing in the Buenos Aires metropolitan area (Argentina). We have chosen popular and middle class families as a response to our interest in analyzing the effects that position in the class structure has on the actions carried out by families for their reproduction. From this point of view, the logic, the decisions, and the goals that lead to access to habitat and to the resources that are mobilized, vary according to the position that families occupy in the class structure. In this article, we advance in the analysis of housing strategies, emphasizing the differences and similarities that are observed among social groups that occupy differential positions in this structure but live in nearby locations in the city, and among social groups occupying similar positions in production and consumption but who reside in different areas and/or locations of the urban space.Fil: Di Virgilio, Maria Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Gil y de Anso, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentin