Microcurrent and the cell: four findings in the literature, and exactly what each one shows

A claim that comes up constantly in bioelectronic medicine is that small electrical currents change what cells do. It is a claim worth taking seriously, because it is testable, and because the published work behind it is considerably more specific than the way that work usually gets summarised.

This note takes four studies from the peer-reviewed literature and, for each one, states three things: what was measured, in what preparation, and what actually follows from it. It closes with the rule that governs how any of this may be applied to a particular device — including mine.

The starting condition: every cell holds a voltage

The reason electricity is relevant to cell biology at all is that cells are already electrical. A living cell maintains a difference in electrical potential across its membrane, with the inside negative relative to the outside. In a resting ventricular heart muscle cell that potential is around −90 millivolts; in a typical neuron it is around −70 millivolts. A millivolt is one thousandth of a volt.

Those numbers look small until the distance is included. A cell membrane is roughly five nanometres thick. Seventy millivolts across five nanometres is an electric field on the order of ten million volts per metre — a field strength that, over laboratory distances, would arc through air. The cell sustains it continuously, and pays for it continuously: the sodium–potassium pump that maintains the underlying ion gradients is one of the larger consumers of ATP in the body.

So the interesting question was never whether electrical phenomena matter inside the body. They demonstrably do. The interesting question is what happens when a current is applied from outside, and how precisely that has been characterised.

Finding 1 — microampere currents change tissue biochemistry

Cheng and colleagues, publishing in Clinical Orthopaedics and Related Research in 1982, applied direct currents from 10 to 1,000 microamperes to rat skin and measured what changed.

Three things did. Tissue ATP concentration increased. Incorporation of amino acids into protein increased. Amino acid transport across the cell membrane was stimulated, over a narrower window of roughly 100 to 750 microamperes. One thing did not change: DNA metabolism, followed by thymidine incorporation, was unaffected over the course of current application. The authors attributed the ATP effect to proton movement under Mitchell's chemiosmotic theory, and the transport effect to modified electrical gradients across the membrane — two separate mechanisms converging on increased protein synthesis.

What it shows: that tissue biochemistry responds to currents in the microampere range, with a dose window rather than a straight line, and through identifiable mechanisms. What it is: a measurement in rat skin, in 1982, of biochemical markers. It is not a clinical outcome in a patient, and it is not a statement about any device.

Finding 2 — the body's own fields are a directional signal, and the pathway is known

Zhao and colleagues published in Nature in 2006 what remains one of the cleanest results in the field. When an epithelial layer is broken, the wound instantaneously generates an endogenous electric field — this happens in every species that has been examined. Their work showed that fields of the strength the body itself produces act as a primary directional cue for the cells migrating to close that wound, and that manipulating the endogenous field changes healing in a living animal.

They then identified the machinery. Electrical stimulation triggered Src and inositol-phospholipid signalling, polarised in the direction of migration. Genetically disrupting phosphatidylinositol-3-OH kinase-gamma reduced the signalling and abolished the directed movement; deleting the tumour suppressor PTEN enhanced both.

What it shows: that electrical signalling in tissue is not a metaphor or an epiphenomenon. It is a control signal with a named molecular pathway that can be switched off genetically. What it is: a study of the body's own fields and of controlled laboratory stimulation, not an evaluation of a therapeutic product.

Finding 3 — the applied-current literature has been reviewed, at length

Kloth's 2005 review in the International Journal of Lower Extremity Wounds is the standard entry point for anyone who wants the applied side rather than the mechanism. It appraises the theory of endogenous bioelectric currents in repair, then works through in vitro research on protein synthesis, cell migration and antibacterial effects, animal work on grafts, donor sites and flaps, and clinical reports on angiogenesis, perfusion, transcutaneous oxygen and epithelialisation — closing with the clinical trials themselves and a glossary of electrical stimulation terminology, which exists because the terminology is genuinely inconsistent between studies.

What it shows: that this is a mature research area with a real clinical literature behind it, not a fringe proposition. What it is: a review of a modality class across many parameter sets, waveforms and indications.

Finding 4 — and a systematic review that states its own limits

Kwan, Lu, Choi, Kloth and Cheing published a systematic review in the International Journal of Molecular Sciences in 2019 covering cell studies and animal experimental models of several biophysical energies: electrical stimulation, pulsed electromagnetic field, extracorporeal shockwave, photo energies and ultrasound. Eighty-two studies met their appraisal criteria out of databases searched back to 1966.

Their conclusion is the most useful sentence in this whole note, and it is their own: the results indicate potential benefits, but the heterogeneity of the current trials means comprehensive, well-designed studies are warranted to confirm them.

What it shows: exactly how a careful group states a positive signal without overstating it. That is the register this field should be written in, and it is the register I try to keep to.

The rule that holds all four together

Evidence for a modality class is not evidence for a particular device.

Every study above concerns applied or endogenous electrical signals in a named preparation at named parameters. None of them tested a commercial product, and a product cannot inherit their results by sharing a category with them. A specific device earns a specific claim only through work done on that device: stated output parameters, a defined protocol, a control arm, prospective enrolment, and an endpoint fixed before the data is collected. That is the same four-layer standard I apply to every technical number I publish, and it does not relax because the subject is biology rather than power electronics.

Where this leaves eMedica

eMedica applies defined voltage, current and frequency parameters to the body — the VCF approach — and the proposed mechanism sits in the same physiology described above: applied parameters influencing membrane-level behaviour and the signalling that depends on it. Proposed is the operative word. The literature in this note establishes that the underlying physiology is real and that the modality class has been studied seriously. It does not, on its own, establish an outcome for this device, and I do not present it as though it does.

For the clinical trial data and the publication record associated with eMedica, the right destination is emedica.in, where that material is held. The design of a proper evidence pathway for an adjuvant device — what exists, what is missing and what would close the gap — is set out separately in the post linked below.

Sources

All four records were retrieved from PubMed.

Cheng N, Van Hoof H, Bockx E, Hoogmartens MJ, Mulier JC, De Dijcker FJ, Sansen WM, De Loecker W. The effects of electric currents on ATP generation, protein synthesis, and membrane transport of rat skin. Clin Orthop Relat Res. 1982;(171):264–72. PMID 7140077.
Zhao M, Song B, Pu J, Wada T, Reid B, Tai G, et al. Electrical signals control wound healing through phosphatidylinositol-3-OH kinase-gamma and PTEN. Nature. 2006;442(7101):457–60. doi.org/10.1038/nature04925
Kloth LC. Electrical stimulation for wound healing: a review of evidence from in vitro studies, animal experiments, and clinical trials. Int J Low Extrem Wounds. 2005;4(1):23–44. doi.org/10.1177/1534734605275733
Kwan RL, Lu S, Choi HM, Kloth LC, Cheing GL. Efficacy of biophysical energies on healing of diabetic skin wounds in cell studies and animal experimental models: a systematic review. Int J Mol Sci. 2019;20(2):368. doi.org/10.3390/ijms20020368

Related
Cell charge and organ function: what membrane voltage is known to control
Immunity and cell charge: the ion channels an immune cell runs on
The Electrical Body: what membrane voltage does, what applied current can and cannot do, and where eMedica's VCF therapy sits in the evidence
Designing an evidence pathway for an adjuvant device: what we have, what is missing, and what would close the gap
How I verify a technical claim before publishing it: the four-layer rule

Hemant K. Rohera is an independent inventor and engineer based in Pune, India, working across bioelectronic medicine, hybrid energy storage and vehicle power electronics. ORCID: 0009-0005-3275-1743

The complete patent register, with a grant number and grant date for every entry, and the research record, with abstracts and DOIs for the deposited notes, are published at hemant-rohera.vercel.app/patent-register.html and hemant-rohera.vercel.app/research.html.