Effects of low frequency electromagnetic fields on the chondrogenic differentiation of human mesenchymal stem cells

Abstract

Electromagnetic fields (EMF) have been shown to exert beneficial effects on cartilage tissue. Nowadays, differentiated human mesenchymal stem cells (hMSCs) are discussed as an alternative approach for cartilage repair. Therefore, the aim of this study was to examine the impact of EMF on hMSCs during chondrogenic differentiation. HMSCs at cell passages five and six were differentiated in pellet cultures in vitro under the addition of human fibroblast growth factor 2 (FGF-2) and human transforming growth factor-β(3) (TGF-β(3) ). Cultures were exposed to homogeneous sinusoidal extremely low-frequency magnetic fields (5 mT) produced by a solenoid or were kept in a control system. After 3 weeks of culture, chondrogenesis was assessed by toluidine blue and safranin-O staining, immunohistochemistry, quantitative real-time polymerase chain reaction (PCR) for cartilage-specific proteins, and a DMMB dye-binding assay for glycosaminoglycans. Under EMF, hMSCs showed a significant increase in collagen type II expression at passage 6. Aggrecan and SOX9 expression did not change significantly after EMF exposure. Collagen type X expression decreased under electromagnetic stimulation. Pellet cultures at passage 5 that had been treated with EMF provided a higher glycosaminoglycan (GAG)/DNA content than cultures that had not been exposed to EMF. Chondrogenic differentiation of hMSCs may be improved by EMF regarding collagen type II expression and GAG content of cultures. EMF might be a way to stimulate and maintain chondrogenesis of hMSCs and, therefore, provide a new step in regenerative medicine regarding tissue engineering of cartilage.

The Role of Physical Factors in Cell Differentiation, Tissue Repair and Regeneration

“…A progressive inhibition of enzyme activity and differentiation in MC-3T3 osteoblast-like cells, after exposure to 30 Hz EMF, was described by McLeod and Collazo (McLeod & Collazo, 2000). In HMSCs exposed to EMFs during chondrogenic differentiation, increase in collagen II and glycosaminoglycan (GAG)/DNA content was observed (Mayer-Wagner et al, 2010). Therefore EMFs might be a way to stimulate and maintain chondrogenesis of HMSCs and provide a new step in regenerative medicine regarding tissue engineering of cartilage.…”

Quasi-optical Systems Based on Periodic Structures

“…Although extremely low electromagnetic fields have been shown to exert beneficial effecets on cartilage tissue (65,66), Lin and Lin investigated the effect of pulsed EMF exposure on osteoblast cells, associated with decreased proliferation and mineralization (67). Okudan, Suslu and co-workers reported the influences of 50 Hz and 0 Hz (static) electric fields (EF), on intact rat bones, as evaluated by dual energy X-ray absorbtion (DEXA) measurements on bone content and density when the animals were continuously exposed in utero and neonatally to EFs.…”

“…the pair of values {κ n , Γ κ n (κ n , φ nκ )}) on each of the surfaces H nκ , n = 1, 2, 3, are completely determined by the condition (63) and the cuts (65). At the first sheets of H nκ the signs of the pairs {κ n , Re Γ κ n } and {κ n , Im Γ κ n } are distributed as follows:…”

Advances in Electromagnetic Therapy for Wound Healing

“…, gene expression 13 , and differentiation 14 are plausibly affected by EMF. Also, the increased intracellular Ca +2 levels 15 , prolonged survival of reactive oxygen species and other free radicals 16 following EMF exposure are well documented.…”