Theory 02/Dermatology & Skin Barrier /Wound healing/3 min
Wounds Heal by Current
A cut shorts out the skin's battery. The current that flows may be the signal that says where to crawl.
Wound healing is driven by an endogenous electric field rather than by chemical gradients alone, so healing rate should be predicted by the wound current and accelerated by applied fields, and drugs that block epithelial ion transport should delay closure.
01The evidence
- Electric fields have been characterised as a key signal in wound healing, with epithelial cells migrating directionally in response to the field that arises when the epithelium is breached.Electric field in wound healing
- Sedentary keratinocytes at the wound edge migrate into the wound guided by the endogenous electric field, which is a directional cue that chemical gradients alone do not supply.Keratinocyte electrotaxis
02The tension
Wound healing is modelled with chemical gradients: growth factors, cytokines, and chemotaxis. Those factors are real and they do not explain directionality at the wound edge, because a diffusing factor has no inherent polarity once the source is distributed along the margin.
03The theory
Intact epithelium maintains a transepithelial potential. When it is breached, current flows out of the wound, creating a steady field whose direction points into the wound and whose magnitude falls with distance.
Cells migrate up the field. The field therefore provides a vector that chemistry cannot, and the rate of closure should scale with the field strength rather than with the concentration of any single factor.
The prediction is that healing rate should correlate with wound current better than with cytokine levels, that applied fields should accelerate closure, and that blocking ion transport should slow it even when growth factors are normal.
The clinical consequence is that electrical stimulation, which has been used empirically for decades, would have a mechanism and a dosing rationale, and that dressings should be designed not to short the field.
04What this is not
Those models explain attraction but not direction. This explains direction with a field, which predicts acceleration from applied current and delay from ion-transport blockade.
05Predictions
- P1Healing rate should correlate with wound current better than with cytokine levels.
- P2Applied fields should accelerate closure.
- P3Ion-transport blockade should delay healing at normal growth factor levels.
06What would refute it
Healing rate independent of field strength at controlled chemistry would leave chemotaxis in charge.
07What it would change
It would give electrical stimulation a mechanism and a dose, and change dressing design.
08Evidence base
- Electric field: a key signal in wound healinghttps://www.sciencedirect.com/science/article/pii/S209669112100090X
- Keratinocyte electrotaxis at the wound edge — publication recordhttps://pesquisa.bvsalud.org/fiocruz/?lang=pt&q=au:%22Pullar,%20Christine%20E%22