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Nature Communications Nov 2022We employ alternating magnetic fields (AMF) to drive magnetic fillers actively and guide the formation and self-healing of percolation networks. Relying on AMF, we...
We employ alternating magnetic fields (AMF) to drive magnetic fillers actively and guide the formation and self-healing of percolation networks. Relying on AMF, we fabricate printable magnetoresistive sensors revealing an enhancement in sensitivity and figure of merit of more than one and two orders of magnitude relative to previous reports. These sensors display low noise, high resolution, and are readily processable using various printing techniques that can be applied to different substrates. The AMF-mediated self-healing has six characteristics: 100% performance recovery; repeatable healing over multiple cycles; room-temperature operation; healing in seconds; no need for manual reassembly; humidity insensitivity. It is found that the above advantages arise from the AMF-induced attraction of magnetic microparticles and the determinative oscillation that work synergistically to improve the quantity and quality of filler contacts. By virtue of these advantages, the AMF-mediated sensors are used in safety application, medical therapy, and human-machine interfaces for augmented reality.
Topics: Humans; Magnetic Fields; Magnetics
PubMed: 36329023
DOI: 10.1038/s41467-022-34235-3 -
Acta Biomaterialia Sep 2021Magnetic fiber composites combining superparamagnetic iron oxide nanoparticles (SPIONs) and electrospun fibers have shown promise in tissue engineering fields....
Assessing the combination of magnetic field stimulation, iron oxide nanoparticles, and aligned electrospun fibers for promoting neurite outgrowth from dorsal root ganglia in vitro.
Magnetic fiber composites combining superparamagnetic iron oxide nanoparticles (SPIONs) and electrospun fibers have shown promise in tissue engineering fields. Controlled grafting of SPIONs to the fibers post-electrospinning generates biocompatible magnetic composites without altering desired fiber morphology. Here, for the first time, we assess the potential of SPION-grafted scaffolds combined with magnetic fields to promote neurite outgrowth by providing contact guidance from the aligned fibers and mechanical stimulation from the SPIONs in the magnetic field. Neurite outgrowth from primary rat dorsal root ganglia (DRG) was assessed from explants cultured on aligned control and SPION-grafted electrospun fibers as well as on non-grafted fibers with SPIONs dispersed in the culture media. To determine the optimal magnetic field stimulation to promote neurite outgrowth, we generated a static, alternating, and linearly moving magnet and simulated the magnetic flux density at different areas of the scaffold over time. The alternating magnetic field increased neurite length by 40% on control fibers compared to a static magnetic field. Additionally, stimulation with an alternating magnetic field resulted in a 30% increase in neurite length and 62% increase in neurite area on SPION-grafted fibers compared to DRG cultured on PLLA fibers with untethered SPIONs added to the culture media. These findings demonstrate that SPION-grafted fiber composites in combination with magnetic fields are more beneficial for stimulating neurite outgrowth on electrospun fibers than dispersed SPIONs. STATEMENT OF SIGNIFICANCE: Aligned electrospun fibers improve axonal regeneration by acting as a passive guidance cue but do not actively interact with cells, while magnetic nanoparticles can be remotely manipulated to interact with neurons and elicit neurite outgrowth. Here, for the first time, we examine the combination of magnetic fields, magnetic nanoparticles, and aligned electrospun fibers to enhance neurite outgrowth. We show an alternating magnetic field alone increases neurite outgrowth on aligned electrospun fibers. However, combining the alternating field with magnetic nanoparticle-grafted fibers does not affect neurite outgrowth compared to control fibers but improves outgrowth compared to freely dispersed magnetic nanoparticles. This study provides the groundwork for utilizing magnetic electrospun fibers and magnetic fields as a method for promoting axonal growth.
Topics: Animals; Ganglia, Spinal; Magnetic Fields; Magnetic Iron Oxide Nanoparticles; Neurites; Neuronal Outgrowth; Rats; Tissue Scaffolds
PubMed: 34271170
DOI: 10.1016/j.actbio.2021.06.049 -
Zoological Research Mar 2023Although 9.4 T magnetic resonance imaging (MRI) has been tested in healthy volunteers, its safety in diabetic patients is unclear. Furthermore, the effects of high...
Although 9.4 T magnetic resonance imaging (MRI) has been tested in healthy volunteers, its safety in diabetic patients is unclear. Furthermore, the effects of high static magnetic fields (SMFs), especially gradient vs. uniform fields, have not been investigated in diabetics. Here, we investigated the consequences of exposure to 1.0-9.4 T high SMFs of different gradients (>10 T/m vs. 0-10 T/m) on type 1 diabetic (T1D) and type 2 diabetic (T2D) mice. We found that 14 h of prolonged treatment of gradient (as high as 55.5 T/m) high SMFs (1.0-8.6 T) had negative effects on T1D and T2D mice, including spleen, hepatic, and renal tissue impairment and elevated glycosylated serum protein, blood glucose, inflammation, and anxiety, while 9.4 T quasi-uniform SMFs at 0-10 T/m did not induce the same effects. In regular T1D mice (blood glucose ≥16.7 mmol/L), the >10 T/m gradient high SMFs increased malondialdehyde ( 0.01) and decreased superoxide dismutase ( 0.05). However, in the severe T1D mice (blood glucose ≥30.0 mmol/L), the >10 T/m gradient high SMFs significantly increased tissue damage and reduced survival rate. cellular studies showed that gradient high SMFs increased cellular reactive oxygen species and apoptosis and reduced MS-1 cell number and proliferation. Therefore, this study showed that prolonged exposure to high-field (1.0-8.6 T) >10 T/m gradient SMFs (35-1 380 times higher than that of current clinical MRI) can have negative effects on diabetic mice, especially mice with severe T1D, whereas 9.4 T high SMFs at 0-10 T/m did not produce the same effects, providing important information for the future development and clinical application of SMFs, especially high-field MRI.
Topics: Mice; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Magnetic Fields; Diabetes Mellitus, Type 2
PubMed: 36650064
DOI: 10.24272/j.issn.2095-8137.2022.460 -
Journal of the Royal Society, Interface Aug 2022Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these... (Review)
Review
Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these phenomena remain elusive. Remarkably, the magnetic energies implicated in these effects are much smaller than thermal energies. Here, we review these observations, and we suggest an explanation based on the radical pair mechanism, which involves the quantum dynamics of the electron and nuclear spins of transient radical molecules. While the radical pair mechanism has been studied in detail in the context of avian magnetoreception, the studies reviewed here show that magnetosensitivity is widespread throughout biology. We review magnetic field effects on various physiological functions, discussing static, hypomagnetic and oscillating magnetic fields, as well as isotope effects. We then review the radical pair mechanism as a potential unifying model for the described magnetic field effects, and we discuss plausible candidate molecules for the radical pairs. We review recent studies proposing that the radical pair mechanism provides explanations for isotope effects in xenon anaesthesia and lithium treatment of hyperactivity, magnetic field effects on the circadian clock, and hypomagnetic field effects on neurogenesis and microtubule assembly. We conclude by discussing future lines of investigation in this exciting new area of quantum biology.
Topics: Animals; Biology; Birds; Magnetic Fields
PubMed: 35919980
DOI: 10.1098/rsif.2022.0325 -
International Journal of Environmental... Jun 2015To examine the association between occupational exposure to extremely-low-frequency magnetic fields (ELF-MF) and Parkinson's disease. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To examine the association between occupational exposure to extremely-low-frequency magnetic fields (ELF-MF) and Parkinson's disease.
METHODS
We systematically searched publications reporting risk estimates of Parkinson's disease in workers exposed to ELF-MF. Summary relative risks were obtained with random effects meta-analysis.
RESULTS
We included 11 studies. To assign exposure, four studies evaluated occupational records, four used census, interview or questionnaire information and three used death certificates. Risk of Parkinson's disease was not elevated in workers exposed to ELF-MF with a summary relative risk of 1.05, 95% CI 0.98-1.13.
CONCLUSIONS
Overall, there was no evidence that the exposure to ELF-MF increases the risk of Parkinson's disease.
Topics: Humans; Magnetic Fields; Occupational Exposure; Parkinson Disease; Risk Assessment
PubMed: 26133127
DOI: 10.3390/ijerph120707348 -
Cells Jan 2022This review contains information on the development of magnetic biology, one of the multidisciplinary areas of biophysics. The main historical facts are presented and... (Review)
Review
This review contains information on the development of magnetic biology, one of the multidisciplinary areas of biophysics. The main historical facts are presented and the general observed properties of magnetobiological phenomena are listed. The unavoidable presence of nonspecific magnetobiological effects in the everyday life of a person and society is shown. Particular attention is paid to the formation of theoretical concepts in magnetobiology and the state of the art in this area of research. Some details are provided on the molecular mechanisms of the nonspecific action of a magnetic field on organisms. The prospects of magnetobiology for the near and distant future are discussed.
Topics: Animals; Biology; Humans; Magnetic Fields; Magnetics; Reproducibility of Results; Research
PubMed: 35053390
DOI: 10.3390/cells11020274 -
Annual Review of Neuroscience Jul 2017Diverse animals ranging from worms and insects to birds and turtles perform impressive journeys using the magnetic field of the earth as a cue. Although major cellular... (Review)
Review
Diverse animals ranging from worms and insects to birds and turtles perform impressive journeys using the magnetic field of the earth as a cue. Although major cellular and molecular mechanisms for sensing mechanical and chemical cues have been elucidated over the past three decades, the mechanisms that animals use to sense magnetic fields remain largely mysterious. Here we survey progress on the search for magnetosensory neurons and magnetosensitive molecules important for animal behaviors. Emphasis is placed on magnetosensation in insects and birds, as well as on the magnetosensitive neuron pair AFD in the nematode Caenorhabditis elegans. We also review conventional criteria used to define animal magnetoreceptors and suggest how approaches used to identify receptors for other sensory modalities may be adapted for magnetoreceptors. Finally, we discuss prospects for underutilized and novel approaches to identify the elusive magnetoreceptors in animals.
Topics: Animal Migration; Animals; Behavior, Animal; Magnetic Fields; Orientation, Spatial; Sensation
PubMed: 28772099
DOI: 10.1146/annurev-neuro-072116-031312 -
Cells Mar 2022The importance of magnetic micro- and nanoparticles for applications in biomedical technology is widely recognised. Many of these applications, including tissue... (Review)
Review
The importance of magnetic micro- and nanoparticles for applications in biomedical technology is widely recognised. Many of these applications, including tissue engineering, cell sorting, biosensors, drug delivery, and lab-on-chip devices, require remote manipulation of magnetic objects. High-gradient magnetic fields generated by micromagnets in the range of 10-10 T/m are sufficient for magnetic forces to overcome other forces caused by viscosity, gravity, and thermal fluctuations. In this paper, various magnetic systems capable of generating magnetic fields with required spatial gradients are analysed. Starting from simple systems of individual magnets and methods of field computation, more advanced magnetic microarrays obtained by lithography patterning of permanent magnets are introduced. More flexible field configurations can be formed with the use of soft magnetic materials magnetised by an external field, which allows control over both temporal and spatial field distributions. As an example, soft magnetic microwires are considered. A very attractive method of field generation is utilising tuneable domain configurations. In this review, we discuss the force requirements and constraints for different areas of application, emphasising the current challenges and how to overcome them.
Topics: Cell Separation; Magnetic Fields; Magnetics; Magnets; Nanoparticles
PubMed: 35326401
DOI: 10.3390/cells11060950 -
Scientific Reports Nov 2021
Topics: Abortion, Spontaneous; Female; Humans; Magnetic Fields; Pregnancy; Risk Factors
PubMed: 34772979
DOI: 10.1038/s41598-021-01391-3 -
International Journal of Molecular... Sep 2022The magneto-mechanical approach is a powerful technique used in many different applications in biomedicine, including remote control enzyme activity, cell receptors,... (Review)
Review
The magneto-mechanical approach is a powerful technique used in many different applications in biomedicine, including remote control enzyme activity, cell receptors, cancer-selective treatments, mechanically-activated drug releases, etc. This approach is based on the use of a combination of magnetic nanoparticles and external magnetic fields that have led to the movement of such nanoparticles with torques and forces (enough to change the conformation of biomolecules or even break weak chemical bonds). However, despite many theoretical and experimental works on this topic, it is difficult to predict the magneto-mechanical effects in each particular case, while the important results are scattered and often cannot be translated to other experiments. The main reason is that the magneto-mechanical effect is extremely sensitive to changes in any parameter of magnetic nanoparticles and the environment and changes in the parameters of the applied magnetic field. Thus, in this review, we (1) summarize and propose a simplified theoretical explanation of the main factors affecting the efficiency of the magneto-mechanical approach; (2) discuss the nature of the MNP-mediated mechanical forces and their order of magnitude; (3) show some of the main applications of the magneto-mechanical approach in the control over the properties of biological systems.
Topics: Magnetic Fields; Magnetics; Nanoparticles
PubMed: 36232435
DOI: 10.3390/ijms231911134