Effects on Collagen Biology and Tendon Mechanical Integrity

Proposal Title

Chronic Environmental ELF-EMF Exposure and Connective Tissue Injury Susceptibility: Effects on Collagen Biology and Tendon Mechanical Integrity

1. Overview

Scientific rationale and importance
A substantial experimental and clinical literature demonstrates that electric and electromagnetic fields can influence soft-tissue repair, fibroblast behavior, collagen synthesis, and extracellular matrix remodeling through non-thermal biophysical mechanisms. These effects have been documented across vitro systems, animal wound models, and therapeutic clinical applications. However, nearly all prior studies involve therapeutic, localized, pulsed, or higher-intensity electromagnetic field exposures intended to enhance healing. Whether chronic, low-intensity environmental exposure to extremely low-frequency electromagnetic fields (ELF-EMF; 60 Hz, 5–50 mG)—such as those produced by electrical substations—can affect connective tissue integrity remains unknown. Tendons, characterized by high collagen content, slow turnover, and limited regenerative capacity, represent a biologically plausible target if cumulative effects exist. This study directly tests that plausibility.

Funding, facilities, and ethics approvals
All experimental work will be conducted using existing cell culture, electromagnetic exposure, and biomechanical testing facilities at [Institution]. No human participants or live animals are involved. Institutional biosafety approval for in vitro and ex vivo tissue research is in place or will be obtained prior to project initiation.

Estimated timeline
Total project duration: 6 months

Month 1: ELF-EMF exposure system calibration and pilot validation
Months 2–4: Chronic exposure experiments and molecular assays
Month 5: Biomechanical testing and data preprocessing
Month 6: Statistical analysis, preregistration-aligned reporting, and data release

Data sharing commitment
All raw data, processed datasets, exposure parameters, and analysis code will be deposited in an open-access repository (e.g., OSF or Zenodo) upon completion, in accordance with ResearchHub requirements.

2. Introduction

Theoretical background and key literature
Biological tissues generate and respond to endogenous electric fields during development, injury, and repair. Extensive foundational work has shown that externally applied electric and electromagnetic fields can influence cellular behavior via non-thermal mechanisms, including membrane polarization, ion flux modulation (particularly calcium), reactive oxygen species signaling, and gene expression changes relevant to extracellular matrix remodeling (Adey, 1981).

Seminal reviews and experimental studies have demonstrated that electric and electromagnetic fields can alter fibroblast proliferation, collagen deposition, matrix metalloproteinase activity, and biomechanical properties of healing tissues (Lee et al., 1993; Aaron & Ciombor, 1993; Pilla, 1999). Animal and in vitro wound models further support EMF-mediated modulation of soft-tissue repair processes (Detlavs et al., 1996; Gualdi et al., 2021). More recent reviews highlight ongoing clinical and tissue-engineering interest in EMF and PEMF therapies for trauma and regeneration (Saliev et al., 2014; Flatscher et al., 2023).

Critically, this literature predominantly examines short-term, therapeutic EMF exposures designed to accelerate healing. The relevance of these findings to chronic, low-level environmental ELF-EMF exposure is unclear. Public attention has recently focused on the hypothesis that long-term exposure to ELF-EMF generated by electrical infrastructure may impair tendon integrity, potentially contributing to elevated soft-tissue injury rates in elite athletic settings. This hypothesis has not been empirically tested.

Research questions

Does chronic exposure to environmental-level ELF-EMF alter collagen synthesis or degradation pathways in tendon-relevant cells?
Does such exposure measurably affect the mechanical properties of engineered tendon constructs?

Hypotheses

H1: Chronic exposure to 60 Hz ELF-EMF at 10–50 mG alters expression of collagen-related genes and proteins (e.g., collagen I, collagen III, MMP-1, MMP-13) in tenocytes and fibroblasts compared to sham exposure.
H2: Engineered tendon constructs exposed to ELF-EMF exhibit reduced ultimate tensile strength and elastic modulus relative to sham-exposed controls.

Impact statement
If effects are detected, this study will provide the first mechanistic evidence supporting biological plausibility for ELF-EMF–related connective tissue vulnerability, motivating further epidemiological and environmental health research. If no effects are observed, the findings will place meaningful empirical constraints on claims linking environmental ELF-EMF exposure to soft-tissue injury risk, helping resolve public speculation with data.

3. Methods

Participants / Sample

Biological samples

Primary human tenocytes
Primary human dermal fibroblasts
Three-dimensional collagen-based engineered tendon constructs seeded with tenocytes

Inclusion criteria

Early-passage cells (≤ passage 5)
Baseline viability ≥90%

Exclusion criteria

Contaminated cultures
Abnormal growth or morphology

Sample size justification
A priori power analysis (α = 0.05, power = 0.80) indicates that n = 10 tendon constructs per exposure group is sufficient to detect a 15% difference in ultimate tensile strength (Cohen’s d ≈ 0.9), consistent with prior connective tissue biomechanics studies.

Materials and Procedure

ELF-EMF exposure system

Helmholtz coil configuration producing uniform 60 Hz magnetic fields
Exposure conditions:
- Sham control (0 mG)
- Low exposure (10 mG)
- High exposure (50 mG)
Exposure duration: 8 hours/day for 21 consecutive days
Continuous temperature monitoring to confirm non-thermal conditions

Cellular and molecular assays

Quantitative PCR and Western blot analysis of collagen I, collagen III, MMP-1, and MMP-13
Total collagen quantification using Sircol assay
Reactive oxygen species assays to assess oxidative stress signaling

Biomechanical testing

Uniaxial tensile testing of engineered tendon constructs
Primary outcomes: ultimate tensile strength, Young’s modulus, strain at failure

Planned Analyses

H1: One-way ANOVA comparing molecular outcomes across exposure groups
- IF normality assumptions are violated → Kruskal–Wallis test
H2: One-way ANOVA for mechanical outcomes with Tukey post-hoc comparisons
Effect sizes reported alongside p-values
Statistical significance threshold: p < 0.05 (two-tailed)

Ethics and Data Management

No human participants or identifiable personal data
Commercially sourced, de-identified biological materials
Data stored on secure institutional servers during collection
Open-access data and code release upon study completion

4. Pilot Data (Optional)

Preliminary system calibration confirms stable generation of ELF-EMF at target field strengths with <0.1 °C temperature fluctuation during prolonged exposure, supporting feasibility for chronic non-thermal experiments. Pilot cell viability assays show no cytotoxic effects over short-term exposure, informing the exposure duration used in the main study.

5. Budget (Estimated)

Item	Cost (USD)
Human tenocytes and fibroblasts	$4,500
Collagen scaffolds and reagents	$5,000
Molecular assay reagents	$6,000
EMF calibration and monitoring equipment	$3,000
Biomechanical testing consumables	$2,500
Research assistant (part-time)	$3,000
Total	$24,000

6. References

1. Adey, W. R. Tissue interactions with nonionizing electromagnetic fields. Physiol. Rev. 61, 435–514 (1981).

2. Lee, R. C., Canaday, D. J. & Doong, H. A review of the biophysical basis for the clinical application of electric fields in soft-tissue repair. J. Burn Care Rehabil. 14, 319–335 (1993).

Aaron, R. K. & Ciombor, D. M. Therapeutic effects of electromagnetic fields in the stimulation of connective tissue repair. J. Cell. Biochem. 52, 42–46 (1993).
Detlavs, I., Dombrovska, L. & Turauska, A. Experimental study of the effects of radiofrequency electromagnetic fields on animals with soft tissue wounds. Sci. Total Environ. 180, 35–42 (1996).
Pilla, A. A. State of the art in electromagnetic therapeutics: soft tissue applications. In Electricity and Magnetism in Biology and Medicine (Springer, 1999).
Saliev, T., Mustapova, Z. & Kulsharova, G. Therapeutic potential of electromagnetic fields for tissue engineering and wound healing. Cell Prolif. 47, 485–493 (2014).
Gualdi, G., Costantini, E., Reale, M. & Amerio, P. Wound repair and extremely low frequency-electromagnetic field: insight from in vitro study and potential clinical application. Int. J. Mol. Sci. 22, 1130 (2021).
Flatscher, J., Pavez Lorie, E., Mittermayr, R. et al. Pulsed electromagnetic fields (PEMF)—physiological response and potential in trauma treatment. Int. J. Mol. Sci. 24, 1145 (2023).
Kim, M. H., Lee, Y. T., Lee, J. H., Kim, K. A. & Kim, S. J. Effect of high frequency electromagnetic wave stimulation on muscle injury in a rat model. Injury 49, 1035–1042 (2018).
Markov, M. S. Expanding use of pulsed electromagnetic field therapies. Electromagn. Biol. Med. 23, 77–92 (2004).
Funk, R. H. W., Monsees, T. K. & Özkucur, N. Electromagnetic effects—from cell biology to medicine. Prog. Histochem. Cytochem. 43, 177–264 (2009).
Ryaby, J. T. Clinical effects of electromagnetic and electric fields on fracture healing. Clin. Orthop. Relat. Res. 355, S205–S215 (1998).
Zhai, X., Zhang, S., Chen, J. & Wang, W. Effects of extremely low frequency electromagnetic fields on fibroblast proliferation and collagen synthesis in vitro. Bioelectromagnetics 36, 65–73 (2015).
Strauch, B., Herman, C., Dabb, R. et al. Evidence-based use of pulsed electromagnetic field therapy in clinical plastic surgery. Ann. Plast. Surg. 44, 589–593 (2000).
Marino, A. A. & Becker, R. O. Biological effects of weak electric fields on cells. Ann. N.Y. Acad. Sci. 238, 242–262 (1974).
Ito, A., et al. Low-frequency electromagnetic field exposure enhances tendon healing in a rat model. J. Orthop. Res. 36, 1234–1242 (2018).
Pall, M. L. Electromagnetic fields act via activation of voltage-gated calcium channels to produce beneficial or adverse effects. J. Cell. Mol. Med. 17, 958–965 (2013).
Rosen, A., Brown, J., Campbell, A. et al. Pulsed electromagnetic fields enhance osteogenic differentiation of human mesenchymal stem cells. Bioelectromagnetics 33, 422–431 (2012).

Effects on Collagen Biology and Tendon Mechanical Integrity

Funding Progress

Nonprofit Recipient

Topics

DOI

Funding Progress

Nonprofit Recipient

Topics

DOI

Effects on Collagen Biology and Tendon Mechanical Integrity

Funding Progress

Nonprofit Recipient

Topics

DOI