Natural electric fields at injury sites steer cells to close wounds, and devices aim to amplify them.
Overview reviewed
When skin or another epithelium is wounded, the disrupted cell layer creates a lateral electric field pointing toward the wound. This was first studied with vibrating-probe measurements in the 1970s and 1980s. Many cell types migrate directionally in such fields (electrotaxis). A landmark study showed that wound fields can override other guidance cues, through PI3K and PTEN signalling (Zhao et al., Nature, 2006).
Electrical stimulation is already used as an adjunct therapy for chronic wounds such as pressure ulcers and diabetic foot ulcers, and several clinical guidelines include it. Trial quality is mixed, however, and the size of the benefit differs between studies and devices.
Wearable and battery-free "electric bandages", closed-loop devices that sense wound state, and DARPA-funded efforts to combine bioelectronic actuation with machine learning aim to make stimulation adaptive. Research continues to find that epithelial cells actively generate and propagate electrical signals after injury.
Well-controlled randomized trials of new wearable devices, and mechanistic work explaining how cells read field direction.
UMass Amherst researchers report that injured epithelial cells, which form the skin and the lining of the intestine, generate electrical signals that spread across dozens of neighbouring cells and persist for hours.
Clusters grown from adult human tracheal cells formed motile, cilia-driven constructs, and in a dish, groups of them encouraged neurons to grow across a scratched area.
A wearable silicone bioreactor delivering a five-drug cocktail to amputation sites for one day triggered 18 months of leg regrowth in adult African clawed frogs, which normally cannot regenerate limbs.