Mathematical Modelling and Numerical Simulation of the Processes in Noninvasive Potentiometric Method of Evaluating Antioxidant/Oxidant State of Skin

摘要

The article proposes theoretical and experimental justification for using potentiometry as a new noninvasive method of evaluating antioxidant/oxidant state (oxidative stress) of a skin. Since the inductor of oxidative stress is an overall deficit of electrons accessible to cells, electrochemical methods of evaluating this parameter are naturally considered as fully corresponding with the nature of the phenomenon. A mathematical model is proposed that describes the processes determining analytical signals in the ‘skin-gel-electrode’ system. The signal occurs as a result of interaction between antioxidants/oxidants diffusing from the epidermis of the skin into the gel and the mediator system oxidised or reduced component introduced into the gel. The information source with regard to AOA/OA (antioxidant/oxidant activity) is the electrode potential shift. It occurs when the gel comes into contact with the skin. The series of potential determining substance-time dependences was obtained as a result of numerical simulation and experiment. Typical relationships between different parameters (chemical reaction rate, gel layer thickness, time) and concentration equal to antioxidant or oxidant activity, (AOA or OA) were found. An agreement between the calculated and experimental data was obtained. Findings analysis enables to forecast features of the experimental relations and provided an opportunity to choose experimental conditions ensuring the most reliable results.