Measurement of microelectric potentials in a bioelectrically-active wound care device in the presence of bacteria

Objective: Wound healing is enhanced in the presence of an external electrical field. The purpose of this study was first to investigate whether nnicroelectric potentials (EPs) can be generated when the innovative design of a silver (Ag)- and zinc (Zn)-printed wound care device was exposed to saline solution which is commonly used to clean wound sites; and second to measure the generated EPs while the device was exposed to bacterial culture suspensions to mimic infection. Method: An Ag/Zn-printed test specimen as a wound care device was designed to accommodate Ag and Zn half-cell potentials by alternatively printing them on a woven polyester material in a well-characterised dot matrix pattern. A well-calibrated high impedance EPs measuring system was used to measure any EPs generated. Ultrasensitive inductively coupled plasma analysis was performed to determine whether the device induced any increase in trace metals in rabbit blood following implantation for 2-4 weeks. Results: EPs were consistently generated under various conductive solutions at the levels of 120.4 +/- 26.3mV (average standard deviation) on Ag dots and -506.5 +/- 76.3mV over Zn dots to form microcircuits with EPs of 626.7 +/- 86.3mV between the Ag and Zn metallic elements of the dressing. Interestingly, the patterns of EPs generated with stable polarities were consistent when the device was exposed to bacterial suspensions for mimicking wound infection. Implantation of the device did not cause any increase in Ag or Zn in rabbit blood. Conclusion: The Ag/Zn-printed wound device generated sustained EPs successfully in the presence of various conductive fluids without changing EPs including polarities. Consistently generated EPs at each battery couple with Ag/Zn-based wound device would restore disrupted physiologic bioelectric signals on wound sites, which could lead to improved wound healing.