Therefore, the two components of SPEF allow combined killing effects on cell membrane and on the subcelluar organelles simultaneously. We had confirmed

that SPEF with different parameters could exert different biophysical effects [8–13] and destroy target area in an intensity-dependent manner [14]. Patients learn more received electrochemotherapy often associated with unpleasant sensations, mainly result from low-frequency (1 Hz) electric pulse induced muscle contractions [25]. Zupanic et al., demonstrated that pulse repetition frequency had a close relation to muscle contraction, increasing the pulse repetition frequencies which higher than tetanic could reduce unpleasant sensations that occur in electrochemotherapy [15]. With respect to electroporation efficiency, Pucihar et al., discovered the absence of a direct influence of high

frequency microsecond electric pulse on the uptake into electropermeabilized KU57788 cells in vitro [16]. Furthermore, similar results by Miklavcic et al., also described that high frequency microsecond electric pulse actually didn’t decreased its antitumor efficiency in electrochemotherapy [17]. On the other hand, pain sensation during electrochemotherapy also involves pulse parameters such as pulse amplitude, number, duration, and shape of the pulses [18]. Generally, for efficient electrochemotherapy, electric pulses of appropriate parameter Selleck C59 must be delivered to the target tissues. However, due to the specificity of SPEF, little data were known regarding the effect of different pulse frequencies on in vitro and in vivo antitumor efficiency by the dual component type of pulse in SPEF. In Vitro and In Vivo Antitumor Efficiency of SPEF In this paper, we studied in vitro and in vivo antitumor efficiency by SPEF with different frequencies and electric field intensity. In vitro test showed that

cytotoxicity of SPEF increased in parallel with electric field intensity. SPEF with a given frequency and electric field intensity could achieve similar cytotoxicity until reached a plateau of maximum cytotoxicity (~100%). Increased pulse repetition frequencies didn’t significantly reduce the maximum value of the cytotoxicity even at the highest frequency (5 kHz). However, higher electric field intensity seemed to be required to obtain the maximum cytotoxicity with the increased repetition frequency of electric pulses. SPEF with 1 Hz or 5 kHz could achieve similar cytotoxicity when accompanied by appropriate electric intensity. Previous research performed by Pucihar et al., also revealed similar result, DC3F cell suspension was exposure to microsecond duration electric pulse, they proved that even if the frequencies reached to 8.3 kHz, electroporation efficiency and the uptake into in vitro electropermeabilized DC3F cells remained unchanged [17].