Synergistic effect of electromagnetic fields and nanomagnetic particles on osteogenesis through calcium channels and p-ERK signaling.

Journal of orthopaedic research : official publication of the Orthopaedic Research Society · 2021 · Benefit · Low evidence

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BenefitLow evidencePaper 5711

Study snapshot

PublicationJournal of orthopaedic research : official publication of the Orthopaedic Research Society · 2021

Study typeanimal

Reported directionBenefit

Evidence ratingLow

Abstract

Electromagnetic fields (EMFs) are widely used in a number of cell therapies and bone disorder treatments, and nanomagnetic particles (NMPs) also promote cell activity. In this study, we investigated the synergistic effects of EMFs and NMPs on the osteogenesis of the human Saos-2 osteoblast cell line and in a rat calvarial defect model. The Saos-2 cells and critical-size calvarial defects of the rats were exposed to EMF (1 mT, 45 Hz, 8 h/day) with or without Fe O NMPs. Biocompatibility was evaluated with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and LDH (lactate dehydrogenase) assays. This analysis showed that NMP and EMF did not induce cell toxicity. Quantitative reverse-transcription polymerase chain reaction indicated that the osteogenesis-related markers were highly expressed in the NMP-incorporated Saos-2 cells after exposure to EMF. Also, the expression of gene-encoding proteins involved in calcium channels was activated and the calcium concentration of the NMP-incorporated + EMF-exposed group was increased compared with the control group. In particular, in the NMP-incorporated + EMF-exposed group, all osteogenic proteins were more abundantly expressed than in the control group. This indicated that the NMP incorporation + EMF exposure induced a signaling pathway through activation of p-ERK and calcium channels. Also, in vivo evaluation revealed that rat calvarial defects treated with EMFs and NMPs had good regeneration results with new bone formation and increased mineral density after 6 weeks. Altogether, these results suggest that NMP treatment or EMF exposure of Saos-2 cells can increase osteogenic activity and NMP incorporation following EMF exposure which is synergistically efficient for osteogenesis.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal

Effect directionbenefit

PopulationHuman Saos-2 osteoblast cell line and rat calvarial defect model

Sample sizeNot supplied

ExposureELF · 8 h/day

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Saos-2 cells and rat calvarial defects exposed to EMF (1 mT, 45 Hz, 8 h/day) with Fe O nanomagnetic particles showed no cell toxicity by MTT/LDH assays. Osteogenesis-related markers and osteogenic proteins were more highly expressed in the NMP+EMF group versus control, with increased calcium concentration and activation of calcium channel-related genes/proteins and p-ERK signaling; in vivo, EMF+NMP treatment was associated with new bone formation and increased mineral density after 6 weeks.

Outcomes measured

Cell toxicity/biocompatibility (MTT, LDH)
Osteogenesis-related marker expression (qRT-PCR)
Calcium channel-related gene/protein expression
Calcium concentration
Osteogenic protein expression
p-ERK signaling activation
Bone regeneration/new bone formation in rat calvarial defects
Mineral density (in vivo, 6 weeks)

Limitations

Sample size not reported in abstract
Details of control/comparator groups and randomization/blinding not described in abstract
Nanomagnetic particle composition/dose not fully specified in abstract (reported as Fe O NMPs)
Exposure parameters beyond field strength, frequency, and daily duration (e.g., total duration, waveform) not described in abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "8 h/day"
  },
  "population": "Human Saos-2 osteoblast cell line and rat calvarial defect model",
  "sample_size": null,
  "outcomes": [
    "Cell toxicity/biocompatibility (MTT, LDH)",
    "Osteogenesis-related marker expression (qRT-PCR)",
    "Calcium channel-related gene/protein expression",
    "Calcium concentration",
    "Osteogenic protein expression",
    "p-ERK signaling activation",
    "Bone regeneration/new bone formation in rat calvarial defects",
    "Mineral density (in vivo, 6 weeks)"
  ],
  "main_findings": "Saos-2 cells and rat calvarial defects exposed to EMF (1 mT, 45 Hz, 8 h/day) with Fe O nanomagnetic particles showed no cell toxicity by MTT/LDH assays. Osteogenesis-related markers and osteogenic proteins were more highly expressed in the NMP+EMF group versus control, with increased calcium concentration and activation of calcium channel-related genes/proteins and p-ERK signaling; in vivo, EMF+NMP treatment was associated with new bone formation and increased mineral density after 6 weeks.",
  "effect_direction": "benefit",
  "limitations": [
    "Sample size not reported in abstract",
    "Details of control/comparator groups and randomization/blinding not described in abstract",
    "Nanomagnetic particle composition/dose not fully specified in abstract (reported as Fe O NMPs)",
    "Exposure parameters beyond field strength, frequency, and daily duration (e.g., total duration, waveform) not described in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "electromagnetic fields",
    "ELF-EMF",
    "45 Hz",
    "1 mT",
    "nanomagnetic particles",
    "Saos-2",
    "osteogenesis",
    "calcium channels",
    "p-ERK",
    "rat calvarial defect",
    "bone regeneration",
    "mineral density"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1002/jor.24905
PubMed: 33150984

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