Biological effects of rotating magnetic field: A review from 1969 to 2021

The effects and mechanisms of electromagnetic fields on bone remodeling: From clinical to laboratory

Electromagnetic fields (EMFs) are physical fields generated by electrically charged objects, and play a vital role in the growth and development of living organisms. Bone is a highly dynamic structure that undergoes a constant remodeling process. From 1962 to 1977, Bassett discovered the piezoelectric effect in bone tissue and found that EMFs accelerated osteogenesis, promoted tibial fracture healing in dogs, and had positive effects in clinical trials. Since then, EMFs have been increasingly studied in bone remodeling disorders as a non-invasive physical therapy. This review summarizes clinical trials and laboratory studies on EMF interventions in bone remodeling disorders over the past few decades, outlining the effects of EMFs on various bone cells and their underlying molecular mechanisms. In addition, we propose issues in current studies and give an outlook on the research and application of EMFs as a non-invasive physical therapy.

The translational potential of this article

This article systematically reviews the research ranging from biological and physical mechanisms to medical applications of EMFs on bone remodeling and related diseases, identifies key challenges in future basic research, and proposes new strategies for developing novel medical equipment and advancing clinical applications in this field. These insights contribute to the advancement of non-invasive physical therapies in orthopedics.

Electromagnetic fields regulate iron metabolism: From mechanisms to applications

BACKGROUND

Electromagnetic fields (EMFs), as a form of physical therapy, have been widely applied in biomedicine. Iron, the most abundant trace metal in living organisms, plays a critical role in various physiological processes, and imbalances in its metabolism are closely associated with the development and progression of numerous diseases. Numerous studies have demonstrated that EMF exposureinduces significant changes in both systemic and cellular iron metabolism.

AIM OF REVIEW

This review aims to summarize the evidence and potential biophysical mechanisms underlying the role of EMFs in regulating iron metabolism, thereby enhancing the understanding of their biological mechanisms and expanding their potential applications in biomedical fields.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this review, we have synthesized research findings and proposed the hypothesis that the biophysical mechanisms of EMFs regulate iron metabolism involve the special electromagnetic properties of iron-containing proteins and iron-enriched tissues, as well as the modulation of membrane structure and function, ion channels, and the generation and activity of Reactive Oxygen Species (ROS). Then, the review summarizes the latest advances in the effects of EMFs on iron metabolism and their safety, as well as their impact on immunoregulation, cardiovascular diseases, neurological diseases, orthopedic diseases, diabetes, liver injury, and cancer.

Effects of mercury and magnetic fields on the activity of proteinases and glycosidases in the intestine of common carp Cyprinus carpio

Aquatic ecosystems are increasingly affected by anthropogenic pollution, including heavy metals like mercury, which accumulate in organisms and cause harmful effects. At the same time, human activities such as industrial operations and the use of electric power lines also alter the magnetic background in natural water bodies. However, the interaction between mercury exposure and magnetic fields remains poorly understood. This study aimed to investigate the combined effects of mercury and magnetic fields on the digestive enzyme activity of common carp (Cyprinus carpio), focusing on the relevance of magnetic fields due to their increasing presence in industrialized environments. Two groups of fish were fed diets with low (0.02 mg/kg) or high (0.27 mg/kg) mercury content for 6 months and exposed to extremely low-frequency magnetic fields or hypomagnetic conditions. Results showed significant differences in mercury accumulation between groups, with higher levels in carps fed with high-mercury content diets. These fish also exhibited increased body length and weight compared to those on a low-mercury diet. The amylolytic activity (total activity of enzymes hydrolyzing starch: α-amylase, glucoamylase, and maltase) and proteolytic activity (total activity of serine proteinases) in the fish intestine were assessed. Magnetic exposure had contrasting effects on enzyme activity, depending on mercury levels in the diet. Fish fed the low-mercury diet exhibited decreased amylolytic activity following magnetic field exposure, while fish on the high-mercury diet showed increased activity. Proteolytic activity followed a similar pattern, with opposite effects observed between the two dietary groups. These findings suggest that mercury accumulation alters the biological response to magnetic fields, possibly through compensatory biochemical mechanisms. Understanding the interactions between toxic substances and magnetic fields is critical for improving environmental risk assessments.

Palliative effect of rotating magnetic field on glucocorticoid-induced osteonecrosis of the femoral head in rats by regulating osteoblast differentiation

With the substantial increase in the overuse of glucocorticoids (GCs) in clinical medicine, the prevalence of glucocorticoid-induced osteonecrosis of the femoral head (GC-ONFH) continues to rise in recent years. However, the optimal treatment for GC-ONFH remains elusive. Rotating magnetic field (RMF), considered as a non-invasive, safe and effective approach, has been proved to have multiple beneficial biological effects including improving bone diseases. To verify the effects of RMF on GC-ONFH, a lipopolysaccharide (LPS) and methylprednisolone (MPS)-induced invivo rat model, and an MPS-induced invitro cell model have been employed. The results demonstrate that RMF alleviated bone mineral loss and femoral head collapse in GC-ONFH rats. Meanwhile, RMF reduced serum lipid levels, attenuated cystic lesions, raised the expression of anti-apoptotic proteins and osteoprotegerin (OPG), while suppressed the expression of pro-apoptotic proteins and nuclear factor receptor activator-κB (RANK) in GC-ONFH rats. Besides, RMF also facilitated the generation of ALP, attenuated apoptosis and inhibits the expression of pro-apoptotic proteins, facilitated the expression of OPG, and inhibited the expression of RANK in MPS-stimulated MC3T3-E1 cells. Thus, this study indicates that RMF can improve GC-ONFH in rat and cell models, suggesting that RMF have the potential in the treatment of clinical GC-ONFH.

Safety of Exposure to 0.2 T and 4 Hz Rotating Magnetic Field: A Ten-Month Study on C57BL/6 Mice

Amidst the burgeoning interest in rotating magnetic fields (RMF) within biological research, there remains a notable gap in the scientific evidence concerning the long-term safety of RMF. Thus, this study aimed to investigate the safety of protracted exposure to a 0.2 T, 4 Hz RMF over 10 months in mice. Two-month-old female C57BL/6 mice were randomly allocated to either the RMF group (exposed to 0.2 T, 4 Hz real RMF) or the SHAM group (exposed to 0 T, 4 Hz sham RMF). Throughout the experiment, the murine weekly body weights were recorded, and their behavioral traits were assessed via open field tests. In the final month, a comprehensive evaluation of the murine overall health was conducted, encompassing analyses of blood parameters, histomorphological examination of major organs, and skeletal assessments using X-ray and micro-CT imaging. The murine immune system and lipid metabolism were evaluated through immunochip analysis and metabolomics. Notably, no discernible adverse effects with RMF exposure were observed. Murine body weight, locomotor behavior, organ histomorphology, and skeletal health remained unaffected by RMF. Blood analysis revealed subtle changes in hormone and lipid levels between the SHAM and RMF groups, yet these differences did not reach statistical significance. Moreover, RMF led to elevated serum interleukin-28 (IL-28) levels, albeit within the normal range, and modest alterations in serum lipid metabolites. Conclusively, mice exposed to the 0.2 T, 4 Hz RMF for 10 months displayed no significant signs of chronic toxicity, indicating its potential clinical application as a physical therapy.

Multifaceted perspectives of detecting and targeting solid tumors

Solid tumors are the most prevalent form of cancer. Considerable technological and medical advancements had been achieved for the diagnosis of the disease. However, detection of the disease in an early stage is of utmost importance, still far from reality. On the contrary, the treatment and therapeutic area to combat solid tumors are still in its infancy. Conventional treatments like chemotherapy and radiation therapy pose challenges due to their indiscriminate impact on healthy and cancerous cells. Contextually, efficient drug targeting is a pivotal approach in solid tumor treatment. This involves the precise delivery of drugs to cancer cells while minimizing harm to healthy cells. Targeted drugs exhibit superior efficacy in eradicating cancer cells while impeding tumor growth and mitigate side effects by optimizing absorption which further diminishes the risk of resistance. Furthermore, tailoring targeted therapies to a patient's tumor-specific molecular profile augments treatment efficacy and reduces the likelihood of relapse. This chapter discuss about the distinctive characteristics of solid tumors, the possibility of early detection of the disease and potential therapeutic angle beyond the conventional approaches. Additionally, the chapter delves into a hitherto unknown attribute of magnetic field effect to target cancer cells which exploit the relatively less susceptibility of normal cells compared to cancer cells to magnetic fields, suggesting a future potential of magnetic nanoparticles for selective cancer cell destruction. Lastly, bioinformatics tools and other unconventional methodologies such as AI-assisted codon bias analysis have a crucial role in comprehending tumor biology, aiding in the identification of futuristic targeted therapies.

Electromagnetic fields effects on microbial growth in cocoa fermentation: A controlled experimental approach using established growth models

Understanding the effects of electromagnetic fields is crucial in the fermentation of cocoa beans, since through precise control of fermentation conditions the sensory and nutritional properties of cocoa beans could be improved. This study aimed to evaluate the effect of oscillating magnetic fields (OMF) on the kinetic growth of the core microbial communities of the Collections Castro Naranjal (CCN 51) cocoa bean. The data was obtained by three different models: Gompertz, Baranyi, and Logistic. The cocoa beans were subjected to different OMF strengths ranging from 0 mT to 80 mT for 1 h using the Helmholtz coil electromagnetic device. The viable microbial populations of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast (Y) were quantified using the colony-forming unit (CFU) counting method. The logistic model appropriately described the growth of LAB and Y under magnetic field exposure. Whereas the Baranyi model was suitable for describing AAB growth. The microbial populations in cocoa beans exposed to magnetic fields showed lower (maximum specific growth rate (μmax), values than untreated controls, with AAB exhibiting the highest average growth rate value at 5 mT and Y having the lowest average maximum growth rate value at 80 mT. The lower maximum specific growth rates and longer lag phases when exposed to magnetic fields compared to controls demonstrate the influence of magnetic fields on microbial growth kinetics.

Adhesion of Escherichia coli and Lactobacillus fermentum to Films and Electrospun Fibrous Scaffolds from Composites of Poly(3-hydroxybutyrate) with Magnetic Nanoparticles in a Low-Frequency Magnetic Field

The ability of materials to adhere bacteria on their surface is one of the most important aspects of their development and application in bioengineering. In this work, the effect of the properties of films and electrospun scaffolds made of composite materials based on biosynthetic poly(3-hydroxybutyrate) (PHB) with the addition of magnetite nanoparticles (MNP) and their complex with graphene oxide (MNP/GO) on the adhesion of E. coli and L. fermentum under the influence of a low-frequency magnetic field and without it was investigated. The physicochemical properties (crystallinity; surface hydrophilicity) of the materials were investigated by X-ray structural analysis, differential scanning calorimetry and "drop deposition" methods, and their surface topography was studied by scanning electron and atomic force microscopy. Crystal violet staining made it possible to reveal differences in the surface charge value and to study the adhesion of bacteria to it. It was shown that the differences in physicochemical properties of materials and the manifestation of magnetoactive properties of materials have a multidirectional effect on the adhesion of model microorganisms. Compared to pure PHB, the adhesion of E. coli to PHB-MNP/GO, and for L. fermentum to both composite materials, was higher. In the magnetic field, the adhesion of E. coli increased markedly compared to PHB-MNP/GO, whereas the effect on the adhesion of L. fermentum was reversed and was only evident in samples with PHB-MNP. Thus, the resultant factors enhancing and impairing the substrate binding of Gram-negative E. coli and Gram-positive L. fermentum turned out to be multidirectional, as they probably have different sensitivity to them. The results obtained will allow for the development of materials with externally controlled adhesion of bacteria to them for biotechnology and medicine.

Pulsed magnetic field increases the effect of ultraviolet C radiation and thermal shock in aged yeasts

The study of the effects of the magnetic field (MF) on living matter continues to be a dilemma. Until now, the interaction mechanisms of MF with living matter that explain the observed phenomena are unknown. Despite the existing literature and the multiple effects described to date, there are few published articles that study the combined effect of MF with other physical agents during the cellular aging process. In this sense, the aim of this work is to study whether low frequency and intensity pulsed and sinusoidal MF exposure produce alterations in the cell killing effect of ultraviolet C (UVC) radiation and thermal shock during the chronological aging of S. cerevisiae. Yeast cells were exposed to 2.45 mT (50 Hz) sinusoidal MF and 1.5 mT (25 Hz) pulsed MF, during 40 days of aging, in combination with UVC radiation (50 J/m2) and/or thermal shock (52°C). Cell survival was evaluated by clonogenic assay. The exposure of yeast to pulsed MF produces an acceleration of aging, which is not observed in cells exposed to sinusoidal MF. The pulsed MF modifies the cellular response to damaging agents only in aged S. cerevisiae cells. In this sense, the pulsed MF applied increases the damage induced by UVC radiation and by thermal shock. In contrast, the sinusoidal MF used has no effect.

Wireless Electrical Signals Induce Functional Neuronal Differentiation of BMSCs on 3D Graphene Framework Driven by Magnetic Field

Bone marrow mesenchymal stem cells (BMSCs) are suggested as candidates for neurodegeneration therapy by autologous stem cells to overcome the lack of neural stem cells in adults. However, the differentiation of BMSCs into functional neurons is a major challenge for neurotherapy. Herein, a methodology has been proposed to induce functional neuronal differentiation of BMSCs on a conductive three-dimensional graphene framework (GFs) combined with a rotating magnetic field. A wireless electrical signal of about 10 μA can be generated on the surface of GFs by cutting the magnetic field lines based on the well-known electromagnetic induction effect, which has been proven to be suitable for inducing neuronal differentiation of BMSCs. The enhanced expressions of the specific genes/proteins and apparent Ca2+ intracellular flow indicate that BMSCs cultured on GFs with 15 min/day rotating magnetic field stimulation for 15 days can differentiate functional neurons without any neural inducing factor. The animal experiments confirm the neural differentiation of BMSCs on GFs after transplantation in vivo, accompanied by stimulation of an external rotating magnetic field. This study overcomes the lack of autologous neural stem cells for adult neurodegeneration patients and provides a facile and safe strategy to induce the neural differentiation of BMSCs, which has potential for clinical applications of neural tissue engineering.

Interaction of magnetic fields with biogenic magnetic nanoparticles on cell membranes: Physiological consequences for organisms in health and disease

The interaction mechanisms between magnetic fields (MFs) and living systems, which remained hidden for more than a hundred years, continue to attract the attention of researchers from various disciplines: physics, biology, medicine, and life sciences. Revealing these mechanisms at the cellular level would allow to understand complex cell systems and could help to explain and predict cell responses to MFs, intervene in organisms' reactions to MFs of different strengths, directions, and spatial distributions. We suggest several new physical mechanisms of the MF impacts on endothelial and cancer cells by the MF interaction with chains of biogenic and non-biogenic magnetic nanoparticles on cell membranes. The revealed mechanisms can play a hitherto unexpected role in creating physiological responses of organisms to externally applied MFs. We have also a set of theoretical models that can predict how cells will individually and collectively respond to a MF exposure. The physiological sequences of the MF - cell interactions for organisms in health and disease are discussed. The described effects and their underlying mechanisms are general and should take place in a large family of biological effects of MFs. The results are of great importance for further developing novel approaches in cell biology, cell therapy and medicine.