Study type: Therapeutical study (experimental study)

Effectiveness of tumor electrochemotherapy as a function of electric pulse strength and duration med. app.

By: Satkauskas S, Batiuskaite D, Salomskaite-Davalgiene S, Venslauskas MS
Published in: Bioelectrochemistry 2005; 65 (2): 105-111
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Aim of study (acc. to author)

To study the effectiveness of electrochemotherapy as a function of various combinations of pulse strength and duration.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1 Hz
Modulation type: pulsed
Exposure 2: 1 Hz
Exposure 3: 1 Hz
Exposure 4: 1 Hz

Exposure 1

Main characteristics
Frequency 1 Hz
Type
Waveform
Modulation
Modulation type pulsed
Additional info

Square-wave electric pulses were generated by an electroporator. The tumors were pulsed with eight-square wave electric pulses of variable strength and duration i.e. 0.1, 0.25, 0.5 and 1 ms.
Exposure setup
Exposure source
  • two flat stainless steel plate electrodes, 8 mm in width, 20 mm in length
Setup 0.2 ml of Bleomycin (BLM) was injected subcutaneously in the right hind limb of the experimental mice. The electrodes were placed at the opposite sides of the tumor and the distance of the plates was adjusted according the size of the tumor
Additional info Treated mice received 5 mg/kg of BLM
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 900 V/cm unspecified cf. remarks - at 0.1, 0.25, 0.5 and 1 ms pulse width

Exposure 2

Main characteristics
Frequency 1 Hz
Type
Waveform
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 110 kV/m unspecified cf. remarks - at 0.1, 0.25, 0.5 and 1 ms pulse width

Exposure 3

Main characteristics
Frequency 1 Hz
Type
Waveform
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 130 kV/m unspecified cf. remarks - at 0.1, 0.25, 0.5 and 1 ms pulse width

Exposure 4

Main characteristics
Frequency 1 Hz
Type
Waveform
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 150 kV/m unspecified cf. remarks - at 0.1, 0.25, 0.5 and 1 ms pulse width

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

At pulse strength of 900 V/cm and duration of 0.1 ms, electrochemotherapy was ineffective. Noticeable inhibition of tumor growth was found when pulse duration at this field strength was increased up to 0.25 ms. Further increase of pulse strength and/or duration resulted in progressive enhancement of antitumor effects.
Using tumor doubling time as a criteria, the authors showed that the same efficacy of electrochemotherapy could be achieved using various pairs of values for pulse strength and duration. Largest antitumor efficacy was revealed at pulse strength of 1500 V/cm and duration of 1 ms.
The findings of this study suggest that the effectiveness of electrochemotherapy can be enhanced if 1500-V/cm, 1-ms electric pulses are used (in comparison to widely accepted conditions of electrochemotherapy-8 pulses of 1300 V/cm, 0.1 ms).

Study character:

Study funded by

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