To study whether the effects of extremely low frequency pulsed electromagnetic fields on cell proliferation, cell cycle and cell differentiation are similar in different-derived osteoblast-like cells (primary cell culture and cell line).
cells were treated in four ways: i) cells cultured for 24 h under PEMF ii) cells cultured for 24 h without PEMF, then exposed for another 24 h to PEMF iii) cells exposed to PEMF for 24 h, then cultured for another 24 h without PEMF iv) cells exposed to PEMF for 48 h
|Exposure duration||continuous for 24 h or 48 h|
|Pulse width||13 ms|
|Repetition frequency||48 Hz|
|Setup||160 turns of 2.06 mm enamel copper wire wound around a 350 mm long cylindrical tube made of epoxy resins with an inner diameter of 190 mm, so that two sub-coils were created; cells placed in the center of the solenoid that was inside an incubator|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||1.55 mT||-||measured||-||-|
1) MC3T3-E1 cells: Exposure to extremely low frequency pulsed electromagnetic field did not affect the cell number. The cell percentage of S phase and G2 phase decreased significantly after 24 h and 48 h. No alkaline phosphatase activity was detected.
2) Primary osteoblast cells: The cell number did not alter after 24 h continuous exposure, but increased greatly after 48 h. The cell percentage of S phase and G2 phase increased significantly after 24 h and decreased significantly after 48 h. The alkaline phosphatase activity decreased significantly after 24 h exposure and increased significantly after 48 h exposure.
In conclusion, in contrast to the MC3T3-E1 cell line, the primary osteoblast cells seemed to be more sensitive to the extremely low frequency-pulsed electromagnetic field.