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.

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.

The Effect of a Rotating Magnetic Field on the Regenerative Potential of Platelets.

Platelets are actively involved in tissue injury site regeneration by producing a wide spectrum of platelet-derived growth factors such as PDGF (platelet-derived growth factor), IGF-1 (insulin-like growth factor), TGF-ß1 (transforming growth factor ß), FGF (fibroblast growth factor), etc. A rotating magnetic field (RMF) can regulate biological functions, including reduction or induction regarding inflammatory processes, cell differentiation, and gene expression, to determine the effect of an RMF on the regenerative potential of platelets. The study group consisted of 30 healthy female and male volunteers (n = 15), from which plasma was collected. A portion of the plasma was extracted and treated as an internal control group. Subsequent doses of plasma were exposed to RMF at different frequencies (25 and 50 Hz) for 1 and 3 h. Then, the concentrations of growth factors (IGF-1, PDGF-BB, TGF-ß1, and FGF-1) were determined in the obtained material by the ELISA method. There were statistically significant differences in the PDGF-BB, TGF-ß1, IGF-1, and FGF-1 concentrations between the analyzed groups. The highest concentration of PDGF-BB was observed in the samples placed in RMF for 1 h at 25 Hz. For TGF-ß1, the highest concentrations were obtained in the samples exposed to RMF for 3 h at 25 Hz and 1 h at 50 Hz. The highest concentrations of IGF-1 and FGF-1 were shown in plasma placed in RMF for 3 h at 25 Hz. An RMF may increase the regenerative potential of platelets. It was noted that female platelets may respond more strongly to RMF than male platelets.

The Influence of Graphene Oxide-Fe3O4 Differently Conjugated with 10-Hydroxycampthotecin and a Rotating Magnetic Field on Adenocarcinoma Cells.

Nanoparticles (e.g., graphene oxide, graphene oxide-Fe3O4 nanocomposite or hexagonal boron nitride) loaded with anti-cancer drugs and targeted at cancerous cells allowed researchers to determine the most effective in vitro conditions for anticancer treatment. For this reason, the main propose of the present study was to determine the effect of graphene oxide (GO) with iron oxide (Fe3O4) nanoparticles (GO-Fe3O4) covalently (c-GO-Fe3O4-HCPT) and non-covalently (nc-GO-Fe3O4-HCPT) conjugated with hydroxycamptothecin (HCPT) in the presence of a rotating magnetic field (RMF) on relative cell viability using the MCF-7 breast cancer cell line. The obtained GO-Fe3O4 nanocomposites demonstrated the uniform coverage of the graphene flakes with the nanospheres, with the thickness of the flakes estimated as ca. 1.2 nm. The XRD pattern of GO-Fe3O4 indicates that the crystal structure of the magnetite remained stable during the functionalization with HCPT that was confirmed with FTIR spectra. After 24 h, approx. 49% and 34% of the anti-cancer drug was released from nc-GO-Fe3O4-HCPT and c-GO-Fe3O4-HCPT, respectively. The stronger bonds in the c-GO-Fe3O4-HCPT resulted in a slower release of a smaller drug amount from the nanocomposite. The combined impact of the novel nanocomposites and a rotating magnetic field on MCF-7 cells was revealed and the efficiency of this novel approach has been confirmed. However, MCF-7 cells were more significantly affected by nc-GO-Fe3O4-HCPT. In the present study, it was found that the concentration of nc-GO-Fe3O4-HCPT and a RMF has the highest statistically significant influence on MCF-7 cell viability. The obtained novel nanocomposites and rotating magnetic field were found to affect the MCF-7 cells in a dose-dependent manner. The presented results may have potential clinical applications, but still, more in-depth analyses need to be performed.

Rotating Magnetic Field-Assisted Reactor Enhances Mechanisms of Phage Adsorption on Bacterial Cell Surface.

Growing interest in bacteriophage research and use, especially as an alternative treatment option for multidrug-resistant bacterial infection, requires rapid development of production methods and strengthening of bacteriophage activities. Bacteriophage adsorption to host cells initiates the process of infection. The rotating magnetic field (RMF) is a promising biotechnological method for process intensification, especially for the intensification of micromixing and mass transfer. This study evaluates the use of RMF to enhance the infection process by influencing bacteriophage adsorption rate. The RMF exposition decreased the t50 and t75 of bacteriophages T4 on Escherichia coli cells and vb_SauM_A phages on Staphylococcus aureus cells. The T4 phage adsorption rate increased from 3.13 × 10-9 mL × min-1 to 1.64 × 10-8 mL × min-1. The adsorption rate of vb_SauM_A phages exposed to RMF increased from 4.94 × 10-9 mL × min-1 to 7.34 × 10-9 mL × min-1. Additionally, the phage T4 zeta potential changed under RMF from -11.1 ± 0.49 mV to -7.66 ± 0.29 for unexposed and RMF-exposed bacteriophages, respectively.

Design and implementation of a highly integrated dual hemisphere capsule robot.

To achieve cancer screening in any appointed position in 3D regions of the gastrointestinal (GI) tract such as esophagus, stomach and colon, a highly integrated dual hemisphere capsule robot (DHCR) with a novel three-layer nested structure is proposed. Based on tracking effect, in which the robotic axis is likely to be approximately coincident with the orientation of the space universal rotating magnetic field (SURMF) using the gyroscope dynamic balance, the dual hemisphere structure realizes the observation at a fixed-point in the passive mode and the rolling locomotion in the active mode by the dynamic posture control of the SURMF manipulation. The image acquisition module, wireless transmission module and driving actuator are tuned in a spherical structure, making the DHCR more compact and less invasive. To verify the maneuverability of the innovative DHCR both for observation at a fixed-point and navigation in curved intestine by aid of image, experiments are conducted in the simulated GI tract environment. The results show that the DHCR achieves effective conversion between posture adjustment and rolling locomotion, which lays a foundation for all-over inspection and medical operation inside 3D regions of the GI tract of human body.

Regulatory and Enterotoxin Gene Expression and Enterotoxins Production in Staphylococcus aureus FRI913 Cultures Exposed to a Rotating Magnetic Field and trans-Anethole.

The study aimed to examine the influence of a rotating magnetic field (RMF) of two different frequencies (5 and 50 Hz) on the expression of regulatory (agrA, hld, rot) and staphylococcal enterotoxin (SE-sea, sec, sel) genes as well as the production of SEs (SEA, SEC, SEL) by the Staphylococcus aureus FRI913 strain cultured on a medium supplemented with a subinhibitory concentration of trans-anethole (TA). Furthermore, a theoretical model of interactions between the bacterial medium and bacterial cells exposed to RMF was proposed. Gene expression and SEs production were measured using quantitative real-time PCR and ELISA techniques, respectively. Based on the obtained results, it was found that there were no significant differences in the expression of regulatory and SE genes in bacteria simultaneously cultured on a medium supplemented with TA and exposed to RMF at the same time in comparison to the control (unexposed to TA and RMF). In contrast, when the bacteria were cultured on a medium supplemented with TA but were not exposed to RMF or when they were exposed to RMF of 50 Hz (but not to TA), a significant increase in agrA and sea transcripts as compared to the unexposed control was found. Moreover, the decreased level of sec transcripts in bacteria cultured without TA but exposed to RMF of 50 Hz was also revealed. In turn, a significant increase in SEA and decrease in SEC and SEL production was observed in bacteria cultured on a medium supplemented with TA and simultaneously exposed to RMFs. It can be concluded, that depending on SE and regulatory genes expression as well as production of SEs, the effect exerted by the RMF and TA may be positive (i.e., manifests as the increase in SEs and/or regulatory gene expression of SEs production) or negative (i.e., manifests as the reduction in both aforementioned features) or none.

Tuning of Magnetic Hyperthermia Response in the Systems Containing Magnetosomes.

A number of materials are studied in the field of magnetic hyperthermia. In general, the most promising ones appear to be iron oxide particle nanosystems. This is also indicated in some clinical trial studies where iron-based oxides were used. On the other hand, the type of material itself provides a number of variations on how to tune hyperthermia indicators. In this paper, magnetite nanoparticles in various forms were analyzed. The nanoparticles differed in the core size as well as in the form of their arrangement. The arrangement was determined by the nature of the surfactant. The individual particles were covered chemically by dextran; in the case of chain-like particles, they were encapsulated naturally in a lipid bilayer. It was shown that in the case of chain-like nanoparticles, except for relaxation, a contribution from magnetic hysteresis to the heating process also appears. The influence of the chosen methodology of magnetic field generation was also analyzed. In addition, the influence of the chosen methodology of magnetic field generation was analyzed. The application of a rotating magnetic field was shown to be more efficient in generating heat than the application of an alternating magnetic field. However, the degree of efficiency depended on the arrangement of the magnetite nanoparticles. The difference in the efficiency of the rotating magnetic field versus the alternating magnetic field was much more pronounced for individual nanoparticles (in the form of a magnetic fluid) than for systems containing chain nanoparticles (magnetosomes and a mix of magnetic fluid with magnetosomes in a ratio 1:1).

The Effect of Rotating Magnetic Field on Susceptibility Profile of Methicillin-Resistant Staphylococcus aureus Strains Exposed to Activity of Different Groups of Antibiotics.

Methicillin-resistant strains of Staphylococcus aureus (MRSA) have become a global issue for healthcare systems due to their resistance to most ß-lactam antibiotics, frequently accompanied by resistance to other classes of antibiotics. In this work, we analyzed the impact of combined use of rotating magnetic field (RMF) with various classes of antibiotics (ß-lactams, glycopeptides, macrolides, lincosamides, aminoglycosides, tetracyclines, and fluoroquinolones) against nine S. aureus strains (eight methicillin-resistant and one methicillin-sensitive). The results indicated that the application of RMF combined with antibiotics interfering with cell walls (particularly with the ß-lactam antibiotics) translate into favorable changes in staphylococcal growth inhibition zones or in minimal inhibitory concentration values compared to the control settings, which were unexposed to RMF. As an example, the MIC value of cefoxitin was reduced in all MRSA strains by up to 42 times. Apart from the ß-lactams, the reduced MIC values were also found for erythromycin, clindamycin, and tetracycline (three strains), ciprofloxacin (one strain), gentamicin (six strains), and teicoplanin (seven strains). The results obtained with the use of in vitro biofilm model confirm that the disturbances caused by RMF in the bacterial cell walls increase the effectiveness of the antibiotics towards MRSA. Because the clinical demand for new therapeutic options effective against MRSA is undisputable, the outcomes and conclusions drawn from the present study may be considered an important road into the application of magnetic fields to fight infections caused by methicillin-resistant staphylococci.

Rotating Magnetic Field Increases ß-Lactam Antibiotic Susceptibility of Methicillin-Resistant Staphylococcus aureus Strains.

Methicillin-resistant strains of Staphylococcus aureus (MRSA) have developed resistance to most ß-lactam antibiotics and have become a global health issue. In this work, we analyzed the impact of a rotating magnetic field (RMF) of well-defined and strictly controlled characteristics coupled with ß-lactam antibiotics against a total of 28 methicillin-resistant and sensitive S. aureus strains. The results indicate that the application of RMF combined with ß-lactam antibiotics correlated with favorable changes in growth inhibition zones or in minimal inhibitory concentrations of the antibiotics compared to controls unexposed to RMF. Fluorescence microscopy indicated a drop in the relative number of cells with intact cell walls after exposure to RMF. These findings were additionally supported by the use of SEM and TEM microscopy, which revealed morphological alterations of RMF-exposed cells manifested by change of shape, drop in cell wall density and cytoplasm condensation. The obtained results indicate that the originally limited impact of ß-lactam antibiotics in MRSA is boosted by the disturbances caused by RMF in the bacterial cell walls. Taking into account the high clinical need for new therapeutic options, effective against MRSA, the data presented in this study have high developmental potential and could serve as a basis for new treatment options for MRSA infections.

Modulation of Cellular Response to Different Parameters of the Rotating Magnetic Field (RMF)-An In Vitro Wound Healing Study.

Since the effect of MFs (magnetic fields) on various biological systems has been studied, different results have been obtained from an insignificant effect of weak MFs on the disruption of the circadian clock system. On the other hand, magnetic fields, electromagnetic fields, or electric fields are used in medicine. The presented study was conducted to determine whether a low-frequency RMF (rotating magnetic field) with different field parameters could evoke the cellular response in vitro and is possible to modulate the cellular response. The cellular metabolic activity, ROS and Ca2+ concentration levels, wound healing assay, and gene expression analyses were conducted to evaluate the effect of RMF. It was shown that different values of magnetic induction (B) and frequency (f) of RMF evoke a different response of cells, e.g., increase in the general metabolic activity may be associated with the increasing of ROS levels. The lower intracellular Ca2+ concentration (for 50 Hz) evoked the inability of cells to wound closure. It can be stated that the subtle balance in the ROS level is crucial in the wound for the effective healing process, and it is possible to modulate the cellular response to the RMF in the context of an in vitro wound healing.

A colorimetric immunosensor for determination of foodborne bacteria using rotating immunomagnetic separation, gold nanorod indication, and click chemistry amplification.

A colorimetric immunosensor was developed for the determination of Salmonella Typhimurium using rotating magnetic separation, gold nanorod (GNR) indication, and click chemistry amplification. The target bacteria were first separated from large-volume sample using a rotating magnetic field and a small amount (50 µg) of immunomagnetic nanoparticles (MNPs), resulting in the forming of magnetic bacteria. Then, the magnetic bacteria were conjugated with catalase (CAT)-labeled antibodies, which were synthesized using trans-cyclooctene/1,2,4,5-tetrazine click chemistry reaction, resulting in the forming of enzymatic bacteria. Then the CATs on the enzymatic bacteria were used to decompose an excessive amount of hydrogen peroxide (H2O2), the remaining H2O2 was mixed with horseradish peroxidase to etch the GNRs, resulting in color change and absorbance peak shift of the GNRs. Finally, the peak shift was measured and analyzed for the quantitative determination of target bacteria. This immunosensor was able to detect Salmonella Typhimurium with a linear range of 101-105 CFU mL-1 in 3 h with a low detection limit of 35 CFU mL-1. The mean recovery for Salmonella Typhimurium in spiked chicken samples was 109%. Graphical abstractSchematic representation of a colorimetric immunosensor for the determination of Salmonella Typhimurium as low as 35 CFU mL-1 using rotating magnetic separation of Salmonella from a large-volume sample, click chemistry reaction of catalase with antibodies for signal amplification, and HRP-mediated gold nanorod etching for result indication.

Moderate intensity low frequency rotating magnetic field inhibits breast cancer growth in mice.

Moderate intensity low frequency rotating magnetic field (LF-RMF) has been shown to inhibit melanoma, liver and lung cancer growth in mice. However, its effects on other types of cancers have not been investigated in vivo. Here, we show that 0-0.15T moderate intensity 4.2 Hz LF-RMF can inhibit tumor growth in mice bearing MDA-MB231 and MCF7 human breast cancer cells by over 30%. In contrast, the human gastrointestinal stromal tumor GIST-T1 growth was not inhibited by LF-RMF. In all RMF treatments, there were no apparent adverse effects on mice organs, body weight or water/food consumptions. However, the alanine aminotransferase (ALT) level was decreased in LF-RMF-treated mice bearing MCF7 and GIST-T1 cells, which indicated alleviated liver damage. Therefore, our study shows that moderate intensity LF-RMF might be a safe physical method that has clinical potentials to be used to inhibit breast cancer growth in the future.

[Design of Electromagnetic Tracking System Using Rotating Magnetic Field Based on DSP].

This paper realized an electromagnetic tracking system based on electrically-controlled rotating magnetic field. A tracking system using the digital signal processor (DSP) as the control processing device was developed, including a controllable constant current source module, a magnetic field source module, a three-axis magnetic sensor and ADC interface circuit. The experimental results verified that each time the system could be stable positioning, average error of position was 0.282 cm, the average error of orientation was 0.696o, the positioning time was 1.572 s. Through calibration and further improvement of the hardware circuit, the performance of the system is expected to further improve.

Forced- and Self-Rotation of Magnetic Nanorods Assembly at the Cell Membrane: A Biomagnetic Torsion Pendulum.

In order to provide insight into how anisotropic nano-objects interact with living cell membranes, and possibly self-assemble, magnetic nanorods with an average size of around 100 nm × 1 µm are designed by assembling iron oxide nanocubes within a polymeric matrix under a magnetic field. The nano-bio interface at the cell membrane under the influence of a rotating magnetic field is then explored. A complex structuration of the nanorods intertwined with the membranes is observed. Unexpectedly, after a magnetic rotating stimulation, the resulting macrorods are able to rotate freely for multiple rotations, revealing the creation of a biomagnetic torsion pendulum.

Enhancing effect of 50 Hz rotating magnetic field on induction of Shiga toxin-converting lambdoid prophages.

Studies aimed at investigating factors and mechanism of induction of prophages, a major pathogenesis factor of Shiga toxin-producing Escherichia coli (STEC), are considered important to develop an effective treatment for STEC infections. In this study, we demonstrated the synergistic effect of the rotating magnetic field (RMF) of induction B = 34 mT and frequency ƒ = 50 Hz at a constant temperature of 37 °C and mitomycin C (MMC), that resulted in a higher level of induction of stx-carrying lambdoid Stx prophages. This is a first report on the induction of lambdoid Stx prophages in response to the enhancing effect of popular inductor (mitomycin C) under the influence of RMF.

Increased water content in bacterial cellulose synthesized under rotating magnetic fields.

The current study describes properties of bacterial cellulose (BC) obtained from Komagataeibacter xylinus cultures exposed to the rotating magnetic field (RMF) of 50 Hz frequency and magnetic induction of 34 mT for controlled time during 6 days of cultivation. The experiments were carried out in the customized RMF exposure system adapted for biological studies. The obtained BC displayed an altered micro-structure, degree of porosity, and water-related parameters in comparison to the non-treated, control BC samples. The observed effects were correlated to the duration and the time of magnetic exposure during K. xylinus cultivation. The most preferred properties in terms of water-related properties were found for BC obtained in the setting, where RMF generator was switched off for the first 72 h of cultivation and switched on for the next 72 h. The described method of BC synthesis may be of special interest for the production of absorbent, antimicrobial-soaked dressings and carrier supports for the immobilization of microorganisms and proteins.

Optimal Length of Low Reynolds Number Nanopropellers.

Locomotion in fluids at the nanoscale is dominated by viscous drag. One efficient propulsion scheme is to use a weak rotating magnetic field that drives a chiral object. From bacterial flagella to artificial drills, the corkscrew is a universally useful chiral shape for propulsion in viscous environments. Externally powered magnetic micro- and nanomotors have been recently developed that allow for precise fuel-free propulsion in complex media. Here, we combine analytical and numerical theory with experiments on nanostructured screw-propellers to show that the optimal length is surprisingly short-only about one helical turn, which is shorter than most of the structures in use to date. The results have important implications for the design of artificial actuated nano- and micropropellers and can dramatically reduce fabrication times, while ensuring optimal performance.

Effects of rotating magnetic field exposure on the functional parameters of different species of bacteria.

The aim of the present study was to determine the effect of the rotating magnetic field (RMF) on the growth, cell metabolic activity and biofilm formation by S. aureus, E. coli, A. baumannii, P. aeruginosa, S. marcescens, S. mutans, C. sakazakii, K. oxytoca and S. xylosus. Bacteria were exposed to the RMF (RMF magnetic induction B = 25-34 mT, RMF frequency f = 5-50 Hz, time of exposure t = 60 min, temperature of incubation 37 °C). The persistence of the effect of exposure (B = 34 mT, f = 50 Hz, t = 60 min) on bacteria after further incubation (t = 300 min) was also studied. The work showed that exposure to RMF stimulated the investigated parameters of S. aureus, E. coli, S. marcescens, S. mutans, C. sakazakii, K. oxytoca and S. xylosus, however inhibited cell metabolic activity and biofilm formation by A. baumannii and P. aeruginosa. The results obtained in this study proved, that the RMF, depending on its magnetic induction and frequency can modulate functional parameters of different species of bacteria.

Anti-ulcerative colitis effect of rotating magnetic field on DSS-induced mice by modulating colonic inflammatory deterioration.

Ulcerative colitis (UC) is a prevalent inflammatory disorder that emerges in the colon and rectum, exhibiting a rising global prevalence and seriously impacting the physical and mental health of patients. Significant challenges remain in UC treatment, highlighting the need for safe and effective long-term therapeutic approaches. Heralded as a promising physical treatment, the rotating magnetic field (RMF) demonstrates safety, stability, manageability, and efficiency. This study delves into RMF's potential in mitigating DSS-induced UC in mice, assessing disease activity indices (DAI) and pathological alterations such as daily body weight, fecal occult blood, colon length, and morphological changes. Besides, several indexes have been detected, including serum concentrations of pro-inflammatory cytokines (IL6, IL-17A, TNF-α, IFN-γ) and anti-inflammatory cytokines (TGF-ß, IL-4, IL-10), the ratio of splenic CD3+, CD4+, and CD8+ T cells, the rate of apoptotic colonic cells, the expression of colonic inflammatory and tight junction-associated proteins. The results showed that RMF had beneficial effects on the decrease of intestinal permeability, the restoration of tight junctions, and the mitigation of mitochondrial respiratory complexes (MRCs) by attenuating inflammatory dysfunction in colons of DSS-induced UC model of mice. In conclusion, this study demonstrates that RMF attenuates colonic inflammation, enhances colonic tight junction, and alleviates MRCs impairment by regulating the equilibrium of pro-inflammatory and anti-inflammatory cytokines in UC mice, suggesting the potential application of RMF in the clinical treatment of UC.