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

Subcellular redistribution of NHERF1 in response to dehydroepiandrosterone (DHEA) administration in endometrial glands of Wistar rats

To understand the regulation of Na(+)/H(+) exchanger regulatory factor (NHERF1) in polycystic ovarian syndrome, we studied the expression of NHERF1 in uterus of Wistar rats injected with (6 mg/kg) of dehydroepiandrosterone (DHEA) for 7 and 20 days. Immunohistochemistry analysis of NHERF1 showed a substantial shift in the intracellular localization of NHERF1 in endometrial glands and areas of luminal epithelium as early as 7 days of DHEA administration. The NHERF1 accumulated in the "Golgi apparatus area" virtually in all the glands in the 7-day protocol, and in the majority of the glands of 20-day protocol. In contrast, NHERF1 is expressed in the apical membrane and slightly in the cytoplasm of the control epithelium. The subcellular redistribution of NHERF1 could affect the sorting of proteins to the apical membrane and the organization of the apical compartment. © 2013 The Author(s).Fil: Kreimann, Erica Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad Presidencia; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); ArgentinaFil: Cabrini, Rómulo L.. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); Argentin

Exfoliative cytology and titanium dental implants: A pilot study

Background: Oral exfoliative cytology is a diagnostic method that involves the study of cells exfoliated from the oral mucosa. Ions/particles released from metallic implants can remain in the peri-implant milieu. The aim of the present study is to assess the presence of metal particles in cells exfoliated from peri-implant oral mucosa around titanium dental implants. Methods: The study comprised 30 patients carrying titanium dental implants, who had neither a metallic prosthesis nor metal restorations in neighboring teeth. Individuals undergoing orthodontic therapy and those who had oral piercing were also excluded from the study. The study sample included patients with and without peri-implantitis. Cytologic samples of the peri-implant area were collected. Samples of the marginal gingiva on the contralateral side of the implant were taken from the same individuals to serve as control. Cytologic analysis was performed using light microscopy. Titanium concentration was determined using inductively coupled plasma-mass spectrophotometry. Results: Metal-like particles were observed inside and outside epithelial cells and macrophages in cytologic smears of peri-implant mucosa of both patients with and without peri-implantitis. No particles were found in the control cytologic samples. The concentration of titanium was higher in the peri-implantitis group compared with the group without peri-implantitis; no traces of titanium were observed in controls. Conclusions: Regardless of an inflammatory response, ions/particles are released from the surface of the implant into the biologic milieu. Exfoliative cytology is a simple technique that may be used to detect metal particles in cells exfoliated from the peri-implant mucosa.Fil: Olmedo, Daniel Gustavo. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nalli, Gabriela. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Verdú, Sergio. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Paparella, María Luisa. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Cabrini, Rómulo L.. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentin

Osteoconductivity of strontium-doped bioactive glass particles: A histomorphometric study in rats

There is accumulating evidence that strontium (Sr)-containing bioceramics have positive effects on bone tissue repair. The aims of the present study were to evaluate the osteoconductivity of Sr-doped bioactive glass (BG) particles implanted in rat tibia bone marrow, and characterize the neoformed bone tissue by SEM-energy-dispersive X-ray microanalysis. Melt-derived BGs were prepared from a base 45S5 BG. Sr-doped glass (45S5.6Sr) was prepared using 6 wt % SrO as a substitute for the CaO. Histological analysis using undecalcified sections showed that new lamellar bone had formed along the surface of both 45S5 and 45S5.6Sr BG particles within 4 weeks. To evaluate osteoconductivity, affinity indices were calculated. At 30 days after implantation, 45S5 and 45S5.6Sr BGs had almost identical affinity indices (88% ± 7% and 87% ± 9%; p > 0.05). Strontium was not detected in the neoformed bone tissue surrounding 45S5.6Sr BG particles. These results indicate that 45S5.6Sr BG particles are osteoconductive when implanted inside the intramedullary canal of rat tibiae, and no alterations in bone mineralization, in terms of Ca/P ratio, were observed in the neoformed bone tissue around 45S5.6Sr BG particles.Fil: Gorustovich Alonso, Alejandro Adrian. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Steimetz, Tammy. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabrini, Rómulo L.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Porto Lopez, Jose Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Qualitative autoradiography with polycarbonate foils enables histological and track analyses on the same section

Neutron autoradiography is an imaging methodology that enables analysis of the spatial distribution of heavy ion emitters in a given material. In particular, it allows localization of 10 B in a tissue section put in contact with a nuclear track detector. Boron imaging is essential when considering boron neutron capture therapy as an option for treating cancerous tumors. A description of the autoradiography method is presented together with specific characteristics and technical details developed in our laboratory. We propose a new mounting technique to compare autoradiography images with the same section that gave rise to the latent tracks. The solid state nuclear track detector is polycarbonate, because it can be processed rapidly to obtain the autoradiographic results. It is a transparent material, which allows visualization of the sections mounted on it. Tissue can be removed easily and background is minimal.Fil: Portu, Agustina Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Carpano, Marina. Comisión Nacional de Energía Atómica; ArgentinaFil: Dagrosa, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Cabrini, Rómulo L.. Comisión Nacional de Energía Atómica; Argentina. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Saint Martin, María Laura Gisela. Comisión Nacional de Energía Atómica; 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