Human Gingival Fibroblasts Exposed to Extremely Low-Frequency Electromagnetic Fields: In Vitro Model of Wound-Healing Improvement

Abstract

Several clinical studies have suggested the impact of sinusoidal and pulsed electromagnetic fields in quickening wound repair processes and tissue regeneration. The clinical use of extremely low-frequency electromagnetic fields could represent a novel frontier in tissue repair and oral health, with an interesting clinical perspective. The present study aimed to evaluate the effect of an extremely low-frequency sinusoidal electromagnetic field (SEMF) and an extremely low-frequency pulsed electromagnetic field (PEMF) with flux densities of 1 mT on a model of oral healing process using gingival fibroblasts. An in vitro mechanical injury was produced to evaluate wound healing, migration, viability, metabolism, and the expression of selected cytokines and protease genes in fibroblasts exposed to or not exposed to the SEMF and the PEMF. Interleukin 6 (IL-6), transforming growth factor beta 1 (TGF-β), metalloproteinase 2 (MMP-2), monocyte chemoattractant protein 1 (MCP-1), inducible nitric oxide synthase (iNOS), and heme oxygenase 1 (HO-1) are involved in wound healing and tissue regeneration, favoring fibroblast proliferation, chemotaxis, and activation. Our results show that the exposure to each type of electromagnetic field increases the early expression of IL-6, TGF-β, and iNOS, driving a shift from an inflammatory to a proliferative phase of wound repair. Additionally, a later induction of MMP-2, MCP-1, and HO-1 was observed after electromagnetic field exposure, which quickened the wound-healing process. Moreover, electromagnetic field exposure influenced the proliferation, migration, and metabolism of human gingival fibroblasts compared to sham-exposed cells. This study suggests that exposure to SEMF and PEMF could be an interesting new non-invasive treatment option for wound healing. However, additional studies are needed to elucidate the best exposure conditions to provide the desired in vivo treatment efficacy.

Evaluation of Salivary Cytokines and Vitamin D Levels in Periodontopathic Patients

“…MMP2 and MMP9 are essential for the initiation of bone remodeling, responsible for managing acute and chronic inflammatory responses [40,41]. In the present study, an increase in MMP9 levels was detected in periodontopathic patients rather than in healthy subjects.…”

Manmade Electromagnetic Fields and Oxidative Stress—Biological Effects and Consequences for Health

“…Together with fluctuations of antioxidative markers, a transient reduction of superoxide, H 2 O 2 , and NO level was reported for MRC-5 lung fibroblasts daily exposed for 1 h to strong 50 Hz ELF-MF (10 mT) for days 1–3, while a prominent increase was found after 7 days [ 197 ]. In the context of investigating the influence of 50 Hz ELF-MF on processes of wound healing and inflammation, a similar exposure duration (3–6 h) in gingival fibroblasts and in HaCaT keratinocytes showed increased iNOS expression and activity, whereas CAT activity and superoxide formation were reduced [ 198 , 199 ]. Similar observations were made in two other cell types, breast (MCF10A) and retinal epithelial cells (RPE-1), in which no signs or even a tendency to reduced oxidative stress were observed after ELF-MF exposure [ 200 , 201 ].…”

Short ELF-EMF Exposure Targets SIRT1/Nrf2/HO-1 Signaling in THP-1 Cells

“…Also, a rapid and sustained elevation in nitric oxide synthetase (NOS) activity, a time-dependent elevation in catalase (CAT) activity, and increased cytochrome (CYP) 450 activity and O 2 − production were observed [ 11 ]. A significant modulation of iNOS, CAT, and CYP 450 protein expression was recorded in cells exposed to ELF-EMF [ 11 , 12 ].…”