Artículos y presentaciones en Congresos



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  • Artículo
    Acceso Abierto
    Active and pH-Sensitive Nanopackaging Based on Polymeric Anthocyanin/Natural or Organo-Modified Montmorillonite Blends: Characterization and Assessment of Cytotoxicity
    (2022) Gutiérrez, Tomy J.; León, Ignacio E.; Ponce, Alejandra C.; Álvarez, Vera A.
    Polymeric anthocyanins are biologically active, pH-sensitive natural compounds and pigments with beneficial functional, pharmacological and therapeutic properties for consumer health. More recently, they have been used for the manufacture of active and pH-sensitive (“intelligent”) food nanopackaging, due to their bathochromic effect. Nevertheless, in order for polymeric anthocyanins to be included either as a functional food or as a pharmacological additive (medicinal food), they inevitably need to be stabilized, as they are highly susceptible to environmental conditions. In this regard, nanopackaging has become a tool to overcome the limitations of polymeric anthocyanins. The objective of this study was to evaluate their structural, thermal, morphological, physicochemical, antioxidant and antimicrobial properties, as well as their responses to pH changes, and the cytotoxicity of blends made from polymeric anthocyanins extracted from Jamaica flowers (Hibiscus sabdariffa) and natural or organo-modified montmorillonite (Mt), as active and pH-sensitive nanopackaging. This study allowed us to conclude that organo-modified Mts are efficient pH-sensitive and antioxidant nanopackaging systems that contain and stabilize polymeric anthocyanins compared to natural Mt nanopackaging and stabilizing polymeric anthocyanins. However, the use of these polymeric anthocyanin-stabilizing organo-modified Mt-based nanopackaging systems are limited for food applications by their toxicity.
  • Resumen
    Acceso Abierto
    Versatility in the biological behavior of two aminobenzoate oxidovanadium (V, IV) compounds. Inhibition or simulation of enzymes
    (2018) Parente, Juliana Elena; Naso, Luciana G.; Jori, Khalil; Arndt, Anderson; Franca, Carlos A.; Costa Ferreira, Ana M. da; Bortolin Uliana, Silvia R.; Pannia Espósito, Breno; Williams, Patricia Ana María; Ferrer, Evelina G.
    The pharmacological potential of vanadium compounds is of great interest to researchers in treatments of various diseases (diabetes, cancer, tropical endemic diseases, etc.). On the basis of the potential biological/pharmacological applications, in this work we have synthesized and physico-chemically characterized, two new complexes containing vanadium (IV) and (V) with 4-aminobenzoic acid as the ligand (L).
  • Artículo
    Acceso Abierto
    Uncertainty studies of topographical measurements on steel surface corrosion by 3D scanning electron microscopy
    (2012) Kang, Kyun Won; Pereda, María Dolores; Canafoglia, María Elena; Bilmes, Pablo David; Llorente, Carlos Luis; Bonetto, Rita
    Pitting corrosion is a damage mechanism quite serious and dangerous in both carbon steel boiler tubes for power plants which are vital to most industries and stainless steels for orthopedic human implants whose demand, due to the increase of life expectation and rate of traffic accidents, has sharply increased. Reliable methods to characterize this kind of damage are becoming increasingly necessary, when trying to evaluate the advance of damage and to establish the best procedures for component inspection in order to determine remaining lives and failure mitigation. A study about the uncertainties on the topographies of corrosion pits from 3D SEM images, obtained at low magnifications (where errors are greater) and different stage tilt angles was carried out by using an in-house software previously developed. Additionally, measurements of pit depths on biomaterial surfaces, subjected to two different surface treatments on stainless steels, were carried out. The different depth distributions observed were in agreement with electrochemical measurements.
  • Artículo
    Potential bio-protective effect of copper compounds: mimicking SOD and peroxidases enzymes and inhibiting acid phosphatase as a target for anti-osteoporotic chemotherapeutics
    (2018) Martini, Nancy; Parente, Juliana Elena; D'Alessandro, Franco; Rey, Marilin; Rizzi, Alberto; Williams, Patricia Ana María; Ferrer, Evelina G.
    Copper complexes with transformed methimazole ligand have been synthesized and characterized by elemental analysis, conductivity measurements, thermogravimetric analysis, EPR, FTIR and UV–Vis spectroscopies. Results support their stoichiometries and geometrical structures: [Cu(C4H5N2S)2Cl2]·2H2O(1), [Cu(C8H10N4S)SO4H2O](2) and [Cu(C8H10N4S)SO4](3). ((C4H5N2)2S: bis(l-methylimidazol-2-yl)sulfide; (C4H5N2S)2 = Bis[bis(l-methylimidazol-2-yl)disulfide]) Concurrently, the structurally distinct soluble species corresponding to complexes (1) and (2) were subsequently used in an in vitro investigation of their potential biological properties. In view of their possible pharmaceutical activity, the complexes were in vitro evaluated as phosphatase acid inhibitors. Their radical bio-protective effects were also studied measuring the effect against DPPH• and O2•− radicals. Additional catalytic properties as peroxidase mimics were evaluated using Michaelis–Menten kinetic model by means of phenol red and pyrogallol assays. The complexes exhibited catalytic bromination activity and the ability to oxidize pyrogallol substrate indicating that they can be considered as functional models. The relationships between the structures and the in vitro biological activities have also been considered. Serum protein albumin has attracted the greatest interest as drug carrier and the affinity of biological/pharmaceutical compound is relevant to the development of new medicine. In that sense, interaction studies by fluorescence and EPR spectroscopies were performed showing the binding capacity of the complexes.
  • Documento de conferencia
    Acceso Abierto
    Sistemas modelos biomiméticos de haloperoxidasas e inhibidores de fosfatasa ácida y alcalina
    (2017) Parente, Juliana Elena; Jori, Khalil; Naso, Luciana G.; Williams, Patricia Ana María; Ferrer, Evelina G.
    El objetivo de esta investigación se centra en el estudio de las potencialidades de los complejos de coordinación con vanadio como simuladores de la actividad desarrollada por las enzimas peroxidasas e inhibidores de la actividad de las fosfatasas.