Medical/biological study (experimental study)

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

By: Chang WH, Chen LT, Sun JS, Lin FH

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

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

Exposure	Parameters
Exposure 1: 15 Hz Modulation type: pulsed Exposure duration: 8 h/day for 14 days	magnetic flux density: 100 µT electric field strength: 2 mV/cm

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 source	coil(s) solenoid
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.

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 µT	-	measured	-	-
electric field strength	2 mV/cm	-	-	-	-

Exposed system:

Investigated system:

Time of investigation:

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:

Zhou J et al. (2016): Sinusoidal electromagnetic fields promote bone formation and inhibit bone resorption in rat femoral tissues in vitro
Bique AM et al. (2016): Choice of osteoblast model critical for studying the effects of electromagnetic stimulation on osteogenesis in vitro
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Zhong C et al. (2012): Effects of Low-Intensity Electromagnetic Fields on the Proliferation and Differentiation of Cultured Mouse Bone Marrow Stromal Stem Cells
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Sun LY et al. (2009): Effect of pulsed electromagnetic field on the proliferation and differentiation potential of human bone marrow mesenchymal stem cells
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