Buenos Aires, Argentina
Buenos Aires, Argentina

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Olaiz N.,Laboratorio Of Sistemas Complejos | Maglietti F.,Laboratorio Of Sistemas Complejos | Suarez C.,Laboratorio Of Sistemas Complejos | Molina F.V.,University of Buenos Aires | And 3 more authors.
Electrochimica Acta | Year: 2010

We have recently shown that in the classical electrochemical treatment (EChT) of tumors, i.e., the passage of a direct electric current through two electrodes inserted locally in the tumor tissue, from an initial uniform condition two pH fronts evolve, expanding towards each other, inducing extreme pH changes and tumor destruction, mainly by necrosis. Here we extend these results introducing a oneprobe two-electrode device (OPTED) containing the cathode and the anode very close to each other (1 mm). Experiments show that upon application of the OPTED-EChT, two half-spherical pH fronts, one basic and the other acid (from cathode and anode, respectively), expand towards the periphery configuring a distorted full sphere. Tracking of the pH front advance reveals a time scaling close to t1/2, signature of a diffusion-controlled process. An analytic model presented allows the estimation of the time needed for total tumor destruction with a minimum compromise of healthy tissue. Main advantages of the OPTED are the insertion of one applicator rather than two or more (thus minimizing tissue intrusion, for instance, in the nervous system), the ability to reach tumors beyond capabilities of conventional surgery and the minimization of electric current circulation through the treated organ. We propose here this new design which could have significant implications in EChT optimal operative conditions, in particular, in the way in which the evolving pH spherical fronts can cover and destroy a cancer cell spherical casket. © 2010 Elsevier Ltd. All rights reserved.

Olaiz N.,Laboratorio Of Sistemas Complejos | Suarez C.,Laboratorio Of Sistemas Complejos | Risk M.,Laboratorio Of Sistemas Complejos | Molina F.,University of Buenos Aires | Marshall G.,University of Manchester
Electrochemistry Communications | Year: 2010

Electrochemical reactions in the electrochemical treatment of tumors (EChT) induce extreme pH changes and, consequently, protein electrodenaturation fronts intimately related to tumor destruction. Here we introduce a new in vitro EChT collagen-macronutrient gel (CMG) model to study protein electrodenaturation fronts as a mean of assessing EChT effectiveness. Our CMG model shows that from an initial uniform condition two electrodenaturation fronts evolve expanding towards each other until collision. Moreover, electrodenaturation front tracking reveals that the front grows under a diffusion-controlled regime. Based on this evidence it is possible, in principle, to predict the time needed for tumor destruction without compromising healthy tissue. These results are consistent with those previously obtained with in vivo and in vitro EChT modeling. In contrast to previous simpler in vitro models, our CMG model represents a better structural and chemical approximation to a real tissue thus providing a better tool for validation of new in silico EChT models aimed at a more accurate prediction of tissue destruction level. © 2009 Elsevier B.V. All rights reserved.

Olivares F.,National University of La Plata | Plastino A.,National University of La Plata | Plastino A.,CONICET | Rosso O.A.,Federal University of Alagoas | And 2 more authors.
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2012

At issue here is the distinction between noise and chaos. They are different phenomena but sometimes produce results that resemble each other. From a numerical viewpoint, in particular, subtle differences that exist between them are often difficult to discern. We present here a conceptual scheme, based on Information Theory, that successfully distinguishes between these two regimes. The idea is to look for the location of the pertinent signal on a special plane, called the information-one, whose axes are entropic-like measures. Using these quantifiers (one local, the other global), the contrast between the two dynamical regimes becomes apparent. © 2012 Elsevier B.V.

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