Study type: Medical/biological study (experimental study)

Effects of THz exposure on human primary keratinocyte differentiation and viability. med./bio.

Published in: J Biol Phys 2003; 29 (2-3): 179-185

Aim of study (acc. to author)

To assess the effects of terahertz irradiation on human skin by assessing the effects on the primary keratinocytes ability to continue growth and normal patterns of differentiation.

Background/further details

Primary human keratinocytes were exposed to different terahertz sources with different durations.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 0.2–3 THz
Modulation type: pulsed
Exposure duration: continuous for 10, 20, or 30 min
Exposure 2: 0.1–2.7 THz
Modulation type: pulsed
Exposure duration: continuous for 10, 20, or 30 min

Exposure 1

Main characteristics
Frequency 0.2–3 THz
Type
Exposure duration continuous for 10, 20, or 30 min
Modulation
Modulation type pulsed
Pulse width 2 ps
Repetition frequency 80 MHz
Additional info

total pulse duration of 20-30 ps with about 90% of the power delivered within the first 2 ps

Exposure setup
Exposure source
  • THz beam system
Chamber A Ti:Sapphire laser was used impacting on an electro-optic photoconverter.
Setup The keratinocytes were seeded into a 96-well tissue culture plate at 100 µl per well. They were exposed through the base of the 96-well plate.
Sham exposure A sham exposure was conducted.
Additional info Two sets of 4 control wells were exposed to the same conditions but not to the THz beam.
Parameters
Measurand Value Type Method Mass Remarks
power 1 µW mean - - -

Exposure 2

Main characteristics
Frequency 0.1–2.7 THz
Type
Exposure duration continuous for 10, 20, or 30 min
Modulation
Modulation type pulsed
Pulse width 0.25 ps
Repetition frequency 250 kHz
Exposure setup
Exposure source
  • THz beam system
Chamber A Ti:Sapphire laser (800 nm) was used impacting on a gallium arsenide wide aperture antenna with a large DC-bias applied across the device. The radiation was collected, collimated, and focused by two parabolae with a spot size of 130 µm to 3.7 mm.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 1 mW mean - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

There were no significant effects following terahertz exposure on the human primary keratinocyte redox potential, compared with the control groups. The differentiation occured in a normal way for exposed and control groups. The fluorescein cadaverine incorporation increased between day 3 and day 8 after exposure.
The results from the different terahertz exposures showed no signs of induced stress to cells.

Study character:

Study funded by

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