Study type: Medical/biological study (experimental study)

Effect of pulse-burst electromagnetic field stimulation on osteoblast cell activities. med./bio.

Published in: Bioelectromagnetics 2004; 25 (6): 457-465

Aim of study (acc. to author)

To study the possible mechanism of the stimulatory effect of pulsed electromagnetic fields on bone cells. Neonatal mouse calvarial bone cell cultures were used.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 15 Hz
Modulation type: pulsed
Exposure duration: 8 h/day for 14 days

Exposure 1

Main characteristics
Frequency 15 Hz
Type
Waveform
Exposure duration 8 h/day for 14 days
Modulation
Modulation type pulsed
Pulse width 0.2 ms
Pulse type monophasic
Additional info

PEMF with a burst width of 5.016 ms, pulse wait of 0.028 ms and burst separation of 61.6 ms; 22 pulses per burst

Exposure setup
Exposure source
Chamber 95% air, 5% CO2 incubator maintained at 37°C
Setup acrylic solenoid (inner diameter 15 cm, length 25 cm, wall thickness 0.5 cm) with 950 +/- 10 turns of 0.6 mm enamel copper wire
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -
electric field strength 2 mV/cm - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The data demonstrated that pulsed electromagnetic fields stimulation significantly increased the osteoblasts' proliferation by 34.0, 11.5, and 13.3% over the control group after 3, 5, and 7 days' culture, but did not affect cellular differentiation, maturation, and mineralization nodule formation. Alkaline phosphatase staining did not change, but the alkaline phosphatase activity of the bone cells decreased significantly after pulsed electromagnetic fields stimulation. Under stimulation, there was no effect on the extracellular matrix synthesis, while the osteoprotegerin mRNA expression was up regulated and the receptor activator of NF-kappa B ligand (RANKL) mRNA expression were down regulated, compared to the control.
In conclusion, the treatment by pulsed electromagnetic fields of osteoblasts may accelerate cell proliferation, but did not affect the cellular differentiation. The effect of stimulation on the bone tissue formation was most likely associated with the increase in the number of cells, but not with the enhancement of the differentiation of the osteoblasts.

Study character:

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