Electronic design of electrode communication control for multiple electrodes in electrochemotherapy and corresponding electric field distribution

Electroporation is a phenomenon that occurs in cell membranes as cells are exposed to sufficiently high electric field. Large molecules, such as some chemotherapeutic drugs or DNA, which otherwise are unable to cross cell membranes may then enter cells. This phenomenon is used in combination with some chemotherapeutic drugs for tumour treatment. Electric field in the tissue is established by voltage application to the electrodes. Usually the voltage applied is in the range of 1000 V for 0.1 to 1 ms. Multiple needle electrodes were already proposed for electrochemotherapy in order to effectively treat larger tumours or to perform the treatment with lower pulse voltages. We developed and tested electrode communication circuit, which controls up to 19 electrodes independently. Each electrode can be in one of three different states: positive, negative or high impedance. In addition, we proposed and tested a pulse sequence using seven electrodes for which we also calculated electric field distribution in tumour tissue by means of finite elements method in 3D model. The electrochemotherapy, which was performed on subcutaneous murine tumour model was demonstrated to be effective (60% complete responses). We also demonstrated that the proposed electrode communication sequence is functional and safe.