National Institute of Industrial Technology

Buenos Aires, Argentina

National Institute of Industrial Technology

Buenos Aires, Argentina
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Herrera L.C.,National Institute of Industrial Technology | Tesoriero M.V.D.,National Institute of Industrial Technology | Hermida L.G.,National Institute of Industrial Technology
Dissolution Technologies | Year: 2012

In the present study, two methods were used to evaluate the in vitro release of leuprolide acetate (LA) from poly(lactide-co-glycolide) (PLGA) microspheres: Franz diffusion cells, typically referred to as "vertical diffusion cells" (VDC), and rotating bottle apparatus (RBA), both modified with a dialysis membrane. This hydrosoluble peptide was chosen as a model drug to study different possibilities of in vitro testing and analyze the variables that affect drug release, respecting sink and physiological conditions. Microspheres were prepared with a conventional double emulsion-solvent evaporation method using PLGA (50:50) with a relatively low molecular weight. Comprehensive stability tests for LA were performed in the conditions used for in vitro release assays. In phosphate-buffered saline (PBS), LA showed no significant degradation, but in an acidic medium, it degraded dramatically. The release profile of the delivery system was governed mainly by diffusion as explained by the low molecular weight of the polymer and the high water solubility of the peptide. The in vitro release profiles were triphasic in vertical diffusion cells and biphasic in the rotating bottle apparatus. The release kinetics was enhanced in RBA with respect to VDC, probably because the constant movement of a suspension of loose microspheres in a large volume and the large membrane area facilitated drug migration. The smoother, triphasic profiles obtained with VDC can be explained by the partial confinement of microspheres, which is similar to the described in vivo behavior of an injectable delivery system.


Monnier S.L.D.,National Institute of Industrial Technology | Mendez A.M.,National Institute of Industrial Technology | Gomez L.G.,National Institute of Industrial Technology | Lago L.D.,National Institute of Industrial Technology
ISPCE 2017 - 2017 IEEE Symposium on Product Compliance Engineering, Proceedings | Year: 2017

This paper will address the general basis for the calculation of uncertainties in the practice for testing electrical and electronic equipments using safety standards, including some calculations for typical tests. © 2017 IEEE.


Pecorelli M.,National Institute of Industrial Technology
18th IMEKO TC4 Symposium on Measurement of Electrical Quantities 2011, Part of Metrologia 2011 | Year: 2011

A new PD (partial discharge) measuring system calibrator is described. The device, battery operated, may be used either grounded or in a floating position, and generates securely mains-synchronized impulses by capacitive coupling. It allows the determination of the scale factor k and resolution time Tr in PD measuring systems, and it fulfils the requirements of International Standard IEC 60270. PD measuring instruments have mains-synchronized sweeps. Hence, in order to have stationary calibration impulses in the PD measuring instrument, the calibrator must generate mains-synchronized impulses. Usually, PD calibrators synchronize to mains frequency by a photodiode. In case of insufficient pick-up of power frequency light, these calibrators automatically select an internal quartz oscillator. When the internal oscillator is on, there is usually a slight difference between the oscillator frequency (fixed) and the mains frequency (variable), and consequently the impulses generated by the internal oscillator are not stationary in the PD measuring instrument (detector screen). This new calibrator avoids that problem because it generates securely mains-synchronized impulses by capacitive coupling, making unnecessary an internal quartz oscillator. Copyright © 2011 by the International Measurement Confederation (IMEKO) All rights reserved.


Gomez G.,National Institute of Industrial Technology
MeMeA 2013 - IEEE International Symposium on Medical Measurements and Applications, Proceedings | Year: 2013

The present paper describe a proposal scheme of calibration of electrosurgery equipment. This work also discuss the operation of electrosurgical equipment, analyzers of electrosurgical equipment and equipment and methods necesary to make the calibrations. © 2013 IEEE.


Monnier S.L.D.,National Institute of Industrial Technology | Mendez A.M.,National Institute of Industrial Technology
Proceedings - 10th Annual IEEE Symposium on Product Compliance Engineering, ISPCE 2013 | Year: 2013

This paper describes the different stages that were necessary in testing microwave ovens for product comparison on the safety laboratory of National Institute of Industrial Technology. Although several departments of the Institute were involved in the comparison, this work will focus only on the work of one of those departments, the safety laboratory. The necessary stages were technical organization, realization and obtained results. The technical organization included the definition of the type of microwave oven used in comparison, selection of microwave power range, capacity and functionality. After that, a selection of test included in comparison was made, taking into account the critical points, the potential interests of users and the capacity of the laboratory. Then the work will explain the criteria used during the realization of tests and the challenges that laboratory should face. Finally, the obtained results were published in a final report and in a brochure friendly to consumers. © 2013 IEEE.


Gallardo G.,National Institute of Industrial Technology | Guida L.,National Institute of Industrial Technology | Martinez V.,National Institute of Industrial Technology | Lopez M.C.,National Institute of Industrial Technology | And 4 more authors.
Food Research International | Year: 2013

Health benefits associated to ω-3 fatty acids consumption together with the high susceptibility to oxidation of ω-3 containing oils have led to the development of microencapsulated oils for nutraceutical and food enrichment applications. The aim of this work is to obtain different formulations for linseed oil microencapsulation by spray-drying with high encapsulation efficiency and evaluate their resistance to oxidation through the accelerated Rancimat test. Four formulations were tested; using different combinations of gum arabic (GA), maltodextrin (MD), methyl cellulose (MC) and whey protein isolate (WPI). Microcapsules made of 100% GA and ternary mixtures of GA, MD and WPI presented the highest protection from oxidation and microencapsulation efficiencies higher than 90%. They also presented spherical structures with smooth surfaces which kept unaltered after 10-month storage. GA containing formulation was included in bread manufacturing. Fortified bread resulted similar in appearance to control bread without microcapsules, but α-linolenic acid content was reduced significantly after preparation. © 2013 Elsevier Ltd.


Cardama G.A.,National University of Quilmes | Gonzalez N.,National University of Quilmes | Ciarlantini M.,National Institute of Industrial Technology | Donadio L.G.,National Institute of Industrial Technology | And 4 more authors.
OncoTargets and Therapy | Year: 2014

Malignant gliomas are characterized by an intrinsic ability to invade diffusely throughout the normal brain tissue. This feature contributes mainly to the failure of existing therapies. Deregulation of small GTPases signaling, in particular Rac1 activity, plays a key role in the invasive phenotype of gliomas. Here we report the effect of ZINC69391, a specific Rac1 inhibitor developed by our group, on human glioma cell lines LN229 and U-87 MG. ZINC69391 is able to interfere with the interaction of Rac1 with Dock180, a relevant Rac1 activator in glioma invasion, and to reduce Rac1-GTP levels. The kinase Pak1, a downstream effector of Dock180-Rac1 signaling, was also downregulated upon ZINC69391 treatment. ZINC69391 reduced cell proliferation, arrested cells in G1 phase, and triggered apoptosis in glioma cells. Importantly, ZINC69391 dramatically affected cell migration and invasion in vitro, interfering with actin cytoskeleton dynamics. We also evaluated the effect of analog 1A-116, a compound derived from ZINC69391 structure. 1A-116 showed an improved antiproliferative and antiinvasive activity on glioma cells. These findings encourage further preclinical testing in clinically relevant animal models. © 2014 Cardama et al.


Bianchetti A.,National Institute of Industrial Technology | Sanchez S.H.,University of Buenos Aires | Cabaleiro J.M.,University of Buenos Aires | Cabaleiro J.M.,University of Marina Mercante
Microfluidics and Nanofluidics | Year: 2016

The build-up of pressure-driven backflows is a known drawback to electroosmotic plug flow. We have studied the characteristic time constant of these pressure gradients build-up as a function of various geometrical variables of the problem through μPIV measurements. Previous models based on hydrostatic pressure difference (syphoning) cannot explain the dynamics of our experimental results. We have developed a model that relates these pressure-driven backflows to Laplace pressures, due to changes in the interface radii of curvature at the reservoirs. This model leads to an equation which was solved both numerically and, after linearisation, analytically. The characteristic time constants obtained show much better agreement with experimental data. Therefore, this model allows for predicting the time during which an acceptable electroosmotic flow profile will last for a given microchannel–reservoir design. © 2016, Springer-Verlag Berlin Heidelberg.


PubMed | National Institute of Industrial Technology and University of Buenos Aires
Type: Journal Article | Journal: PloS one | Year: 2015

Multicellular tumor spheroids represent a 3D in vitro model that mimics solid tumor essential properties including assembly and development of extracellular matrix and nutrient, oxygen and proliferation gradients. In the present study, we analyze the impact of 3D spatial organization of HER2-overexpressing breast cancer cells on the response to Trastuzumab. We cultured human mammary adenocarcinoma cell lines as spheroids with the hanging drop method and we observed a gradient of proliferating, quiescent, hypoxic, apoptotic and autophagic cells towards the inner core. This 3D organization decreased Trastuzumab sensitivity of HER2 over-expressing cells compared to monolayer cell cultures. We did not observe apoptosis induced by Trastuzumab but found cell arrest in G0/G1 phase. Moreover, the treatment downregulated the basal apoptosis only found in tumor spheroids, by eliciting protective autophagy. We were able to increase sensitivity to Trastuzumab by autophagy inhibition, thus exposing the interaction between apoptosis and autophagy. We confirmed this result by developing a resistant cell line that was more sensitive to autophagy inhibition than the parental BT474 cells. In summary, the development of Trastuzumab resistance relies on the balance between death and survival mechanisms, characteristic of 3D cell organization. We propose the use of spheroids to further improve the understanding of Trastuzumab antitumor activity and overcome resistance.


PubMed | National Institute of Industrial Technology and National University of Quilmes
Type: | Journal: OncoTargets and therapy | Year: 2014

Malignant gliomas are characterized by an intrinsic ability to invade diffusely throughout the normal brain tissue. This feature contributes mainly to the failure of existing therapies. Deregulation of small GTPases signaling, in particular Rac1 activity, plays a key role in the invasive phenotype of gliomas. Here we report the effect of ZINC69391, a specific Rac1 inhibitor developed by our group, on human glioma cell lines LN229 and U-87 MG. ZINC69391 is able to interfere with the interaction of Rac1 with Dock180, a relevant Rac1 activator in glioma invasion, and to reduce Rac1-GTP levels. The kinase Pak1, a downstream effector of Dock180-Rac1 signaling, was also downregulated upon ZINC69391 treatment. ZINC69391 reduced cell proliferation, arrested cells in G1 phase, and triggered apoptosis in glioma cells. Importantly, ZINC69391 dramatically affected cell migration and invasion in vitro, interfering with actin cytoskeleton dynamics. We also evaluated the effect of analog 1A-116, a compound derived from ZINC69391 structure. 1A-116 showed an improved antiproliferative and antiinvasive activity on glioma cells. These findings encourage further preclinical testing in clinically relevant animal models.

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