Nanotecnología: ¿Revolución científico-tecnológica de pequeños riesgos?

La nanotecnología es un campo de las ciencias aplicadas dedicado al control y manipulación de la materia a nivel de átomos y moléculas, en un rango comprendido entre uno y cien nanómetros. Permite la creación de materiales, dispositivos y sistemas mediante el control de la materia a esa escala. En el campo de la Odontología se han desarrollado bio-sensores altamente especializados, que permitirían la identificación de enfermedades en la saliva. En un futuro cercano será clave su uso en el diagnóstico de enfermedades de alto impacto como el cáncer de mama, ovario y páncreas, enfermedad de Alzheimer, SIDA, diabetes y osteoporosis.Fil: Olmedo, Daniel Gustavo. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patologica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tasat, Deborah R.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Cabrini, Rómulo L.. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patologica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Audebert, Fernando Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica; ArgentinaFil: Guglielmotti, Maria Beatriz. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patologica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

In vitro age dependent response of macrophages to micro and nano titanium dioxide particles

As a result of corrosion, microparticles (MP) and/or nanoparticles (NP) can be released from the metallic implants surface into the bioenvironment. The biological response to these particles depends not only on the physico-chemical properties of the particles but also on host factors, such as age. Macrophages have attracted wide concern in biomedicine. The aim of this investigation was to study the age related biological response of macrophages to TiO2-MP and NP in vitro. Alveolar macrophages (AM) obtained from young and senescent rats were cultured and exposed to TiO2-MP and NP. Cell metabolism, superoxide anion (O2−) and nitric oxide (NO) generation, and cytokine release (IL-6, TNFα, IL-10) were measured. Cell metabolism was not affected by particle exposure. O2− and NO generation increased in a dose dependent manner. A marked increase on IL-6 release was found in the young-AM subpopulation exposed to TiO2-MP. Conversely, both particle sizes induced a dose dependent release of TNFα in senescent-AM. Only the highest concentration of TiO2-particles caused a significant increase in IL-10 release in AM-cultures. These observations lend strong support to the suggestion that cellular response of macrophages to TiO2-particles is age dependent. The biological effect of the particles would seem to be more deleterious in the senescent age-group.Fil: Bruno, Marcos E.. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Sittner, Maximiliano. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Cabrini, Romulo L.. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Academia Nacional de Medicina de Buenos Aires; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; ArgentinaFil: Guglielmotti, Maria Beatriz. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Olmedo, Daniel Gustavo. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tasat, Deborah R.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Histología y Embriología; Argentin

In vivo comparative biokinetics and biocompatibility of titanium and zirconium microparticles.

Titanium and zirconium are biomaterials that present a layer of titanium dioxide (TiO(2)) or zirconium dioxide (ZrO(2)). As a result of corrosion, microparticles can be released into the bioenvironment, and their effect on tissues is seemingly associated with differences in the physicochemical properties of these metals. The aim of this study was to perform a long-term evaluation of the distribution, destination, and potential risk of TiO(2) and ZrO(2) microparticles that might result from the corrosion process. Wistar rats were i.p. injected with an equal dose of either TiO(2) or ZrO(2) suspension. The following end-points were evaluated at 3, 6, and 18 months: (a) the presence of particles in blood cells and liver and lung tissue, (b) Ti and Zr deposit quantitation, (c) oxidant-antioxidant balance in tissues, and (d) O(2)(-) generation in alveolar macrophages. Ti and Zr particles were detected in blood mononuclear cells and in organ parenchyma. At equal doses and times postadministration, Ti content in organs was consistently higher than Zr content. Ti elicited a significant increase in O(2)(-) generation in the lung compared to Zr. The consumption of antioxidant enzymes was greater in the Ti than in the Zr group. The present study shows that the biokinetics of TiO(2) and ZrO(2) depends on particle size, shape, and/or crystal structure.Fil: Olmedo, Daniel Gustavo. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Tasat, Deborah R.. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Evelson, Pablo Andres. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Rebagliatti, Raúl. Comision Nacional de Energia Atomica; ArgentinaFil: Guglielmotti, Maria Beatriz. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Cabrini, Rómulo L.. Comision Nacional de Energia Atomica; Argentina. Universidad de Buenos Aires. Facultad de Odontología; Argentin

Active caspase-3 expression levels as bioindicator of individual radiosensitivity

ABSTRACT Several molecules and events involved in cell response to radiation-induced damage have been investigated towards a personalized radiotherapy. Considering the importance of active caspase-3 in the proteolytic cascade that ensures radiation-induced apoptosis execution, this research was designed to evaluate the expression levels of this protein as a bioindicator of individual radiosensitivity. Peripheral blood samples of 10 healthy individuals were gamma-irradiated (cobalt-60 source) with 1, 2 and 4 Gy (control: non-irradiated samples), and active caspase-3 expression levels were measured in lymphocytes, by flow cytometry, ex vivo and after different times of in vitro incubation (24, 48 and 72 hours). Short-term incubation of 24 h was the most adequate condition to evidence correlations between dose radiation and active caspase-3 expression. For each radiation dose, it was observed a significant inter-individual variation in active caspase-3 expression intensity, suggesting that this parameter may be suitable for evidence individual radiosensitivity. The methodology presented and discussed in this work may help to predict healthy tissues response to radiation exposure toward the better patient outcome