Electrochemical treatment of tumors: tracking study of electrodenaturation fronts propagating from a one-probe two-electrode device (OPTED)

NAHUEL OLAIZ; FELIPE MAGLIETTI; CECILIA SUÁREZ; FERNANDO MOLINA; GUILLERMO MARSHALL

Niza, Francia

Congreso; 61st Annual Meeting of the International Society of Electrochemistry; 2010

We have recently shown, using a collagen macronutrient gel (CMG) model, that in theclassical electrochemical treatment (EChT) of tumors (the passage of a directelectric current through two electrodes inserted locally in the tumor tissue), from aninitial uniform condition two electrodenaturation fronts evolve, expanding towardseach other, inducing tumor destruction. Here we present results using a CMG modelsystem in conjunction with one-probe two-electrode device (OPTED) containingthe cathode and the anode very close to each other (1 mm). Experiments show thatupon application of a potential difference to the CMG-OPTED, two half sphericalelectrodenaturation fronts (one acid and the other alkaline) expand towards theperiphery configuring a distorted full sphere. Tracking of the electrodenaturationfront 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 totaltumor destruction with a minimum compromise of healthy tissue.The sphere maximum diameter is a function of the dose (charge) applied, as well as theavailability of water, which can be exhausted thus stopping the production of H+and OH-. However, comparing with the separated-electrodes approach currentlyemployed, using the OPTED a gain of about 25% is obtained due to waterrecombination. Besides, water can be injected to improve conditions as it has beenreported.Main advantages of the OPTED-EChT are the insertion of one applicator rather thantwo or more (thus minimizing tissue intrusion, for instance, in the nervous system)and the minimization of electric current circulation through the treated organ.Moreover, in contrast to previous simpler in vitro models, the use of the CMGmodel represents a better structural and chemical approximation to a real tissue thusproviding a better tool for validation of new in silico EChT models aimed at a moreaccurate prediction of tissue destruction level.