The effect of high frequency electric pulses on muscle contractions and antitumor efficiency in vivo for a potential use in clinical electrochemotherapy

Advances in Therapeutic Electroporation to Mitigate Muscle Contractions

“…While applying bursts of microsecond-long unipolar pulses can reduce the total number of muscle contractions per treatment, the force of contraction is similar to that generated during an individual unipolar pulse [26]. However, as alluded to by Daskalov et al [21], altering pulse polarity can be employed to reduce the intensity of muscle contractions.…”

“…Additionally, for the application of eight pulses as a single burst, the patients experienced only a single electrical sensation, as opposed to series of eight [21]. The technique of raising the pulse repetition rate above the frequency of tetanic contraction was later confirmed to be an effective option for unipolar pulsing as well [18,26], assuming optimal drug dosing [27].…”

Evaluation of the Electroporation Efficiency of a Grid Electrode for Electrochemotherapy

“…Specifically, among the electroporated cells (which appeared red with fluorescence microscopy, because it is positive to PI), it has been possible to discriminate between viable cells (ie, exposed to reversible electroporation, which appeared blue because it is positive to CB) from those dead (ie, exposed to irreversible electroporation, which do not appear blue colored because it is negative to CB). 21,25 Voltage pulses (10 rectangular pulses with an amplitude of 2000 V, a pulse period of 10 ms, a pulse length of 100 ms, and a repetition frequency of 100 Hz 20,43,44 ) were delivered to the cells by means of the model B of grid electrode ( Figure 2B) which was connected to the pulse generator. After pulse delivery, the cells were maintained in the same position for 2 minutes at room temperature to avoid any mechanical stress for the cells.…”

Antivascular effects of electrochemotherapy: implications in treatment of bleeding metastases

“…Plate electrodes are used for the treatment of small and superficial metastases, whereas needle electrodes are used predominantly for deeper-seated nodules or exophytic nodules [23,25,45]. The duration of individual pulses is usually 100 µs and the repetition frequency is set to 1 Hz, although high-frequency (kHz range) frequencies can also be used [5,23,46,47]. When choosing the appropriate amplitude of pulses, both the geometrical distance between the electrodes and the configuration of the electrodes must be considered.…”