? For over a century we have known that human skin drives ionic current out of wounded regions. DuBois- Reymond (1848) used one of the earliest galvanometers to measure 1 microampere leaving wounds in his skin. This has been confirmed using modern techniques and we now know that this current is driven out of the wound by the transepithelial potential generated across the epidermis. As this wound current traverses the epidermis it generates a local electric field that points towards the wound from all directions around it. It is this signaling capability of the electric field that is most intriguing, yet no one has ever measured these electric fields in wounds. Electric fields can signal that a wound has occurred by exerting a force on charged molecules by electrophoresis or by influencing local skin cell movement by galvanotaxis. The movement of human skin cells can be strongly influenced by electric fields. Previous investigations found that human skin cells actively migrate towards the negative pole in fields of 10-400 mV/mm. It is very exciting that the field strengths we have recently measured in wounds during our Phase I SBIR research are identical to this. We successfully applied a new instrument called the Bioelectric Field Imager (BFI) to non-invasively measure this wound field in both mouse and human skin. We found that a field of 200 mV/mm is present immediately following wounding and persists until wound healing is complete. Moreover, this novel technique is noninvasive and allows these measurements to be made with minimal disturbance to the skin wound. During Phase II we will refine the design of the BFI to allow the measurement of skin wound fields on most surfaces of the human body. This will include eventually making the device much smaller and lighter so that it can be hand-held, and making it faster so that an image can be generated with only two seconds of data collection. We will accomplish this rapid signal acquisition by using a multi-sensor array in conjunction with simultaneous data acquisition from each sensor. These improvements will allow us to place the BFI on any body region much like a stethoscope and rapidly collect an image of the electric field in the skin beneath it. Once we have made these refinements to the BFI, we will evaluate its utility for the non-invasive quantification of the rate of wound healing as well as the diagnosis of wounds with abnormal electric fields. This will have many important applications to improving human health including the design of new electrical therapies for stimulating the healing of chronic wounds and possibly the early detection and diagnosis of skin diseases. ? ?
| Nuccitelli, Richard; Nuccitelli, Pamela; Li, Changyi et al. (2011) The electric field near human skin wounds declines with age and provides a noninvasive indicator of wound healing. Wound Repair Regen 19:645-55 |
| Nuccitelli, Richard; Nuccitelli, Pamela; Ramlatchan, Samdeo et al. (2008) Imaging the electric field associated with mouse and human skin wounds. Wound Repair Regen 16:432-41 |
| Reid, Brian; Nuccitelli, Richard; Zhao, Min (2007) Non-invasive measurement of bioelectric currents with a vibrating probe. Nat Protoc 2:661-9 |
| Nuccitelli, Richard; Pliquett, Uwe; Chen, Xinhua et al. (2006) Nanosecond pulsed electric fields cause melanomas to self-destruct. Biochem Biophys Res Commun 343:351-60 |
| Frey, W; White, J A; Price, R O et al. (2006) Plasma membrane voltage changes during nanosecond pulsed electric field exposure. Biophys J 90:3608-15 |
