ABSTRACT

Tissue engineering approaches have provided treatment options for patients with limited cartilage repair capacity. Most of these approaches rely on isolating and expanding chondrocytes in vitro. Mechanical stress, ultrasound, and electric and electromagnetic fields (EMFs) can be used to stimulate cartilage repair. EMF has been used in the management of conditions such as arthritis and fractures. Most of the previous studies have focused on low-frequency pulsed EMF (PEMF). The aim of the present study was to investigate the effects of low-frequency continuous (sinusoidal) EMF (CEMF) versus PEMF on chondrocytes.

Chondrocytes from bovine nasal cartilage were exposed to low-frequency CEMF versus PEMF, and the proliferation and differentiation capacities of these chondrocytes were determined. The effects of EMFs on retinoic acid receptor beta and transforming growth factor beta (TGF-β) expressions were investigated using quantitative reverse transcription polymerase chain reaction.

Our observations suggested that there was no difference between the effects of PEMF and CEMF exposure on the proliferation and differentiation capacities of chondrocytes.

EMF-mediated proliferation of chondrocytes requires the presence of growth factors, especially insulin-like growth factor, in the environment to maintain the chondrogenic phenotype; furthermore, the EMF effect on chondrocytes is independent of TGF-β.