Study type: Medical/biological study (experimental study)

The response of giant phospholipid vesicles to millimeter waves radiation. med./bio.

Published in: Biochim Biophys Acta Biomembr 2009; 1788 (7): 1497-1507

Aim of study (acc. to author)

To study the effects of low-intensity millimeter waves at 53.37 GHz (considered as "therapeutic" frequency) on membrane model systems (giant vesicles).

Background/further details

Giant vesicles have a size in the micrometer range, i.e. are of cell-size, and could reflect the membrane properties and "behavior" that occur in the cell membrane.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 53.37 GHz
Exposure duration: 30 s, 1 min, 2 min or 4 min

Exposure 1

Main characteristics
Frequency 53.37 GHz
Type
Charakteristic
Exposure duration 30 s, 1 min, 2 min or 4 min
Exposure setup
Exposure source
Distance between exposed object and exposure source 8 cm
Setup conocal horn antenna fixed above the samples so that the incident angle of the radiation was 45°
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 39 mW - - - -
electric field strength 20 V/m - measured - +/- 10 %
SAR 0.1 W/kg minimum calculated - -
SAR 0.5 W/kg maximum calculated - -
power density 0.1 mW/cm² - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The data showed physical changes of vesicles, i.e. elongation, induced diffusion of the fluorescent dye, and increased attractions between vesicles. These effects were reversible and occured only during irradiation. Since the average temperature change was very small the effects can not be attributed to thermal mechanisms.
The authors assume that the interaction of millimeter waves with lipid bilayer leads to changes at the membrane-water interface, where charged and dipolar residues of molecules are located.

Study character:

Study funded by

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