chapter  6
18 Pages

Physiological Electric Fields Can Direct Keratinocyte Migration and Promote Healing in Chronic Wounds

Introduction ....................................................................................................... 138 The Skin ............................................................................................................ 138 An Overview of Skin Wound Repair ................................................................ 139 Chronic Wounds ................................................................................................ 140 The Use of Applied Direct Current Electric Fields to Heal Chronic Wounds .. 140 Wound Cell Physiology Can Be Directed by Physiological EFs In Vitro ..........141 An Applied DC EF Can Alter the Direction of Cell Migration .........................141 Primary Human Keratinocytes .......................................................................... 142 Experimental Conditions .................................................................................. 142 Keratinocytes Migrate toward the Cathode of an Applied Electric Field of 100 mV/mm .......................................................................................................143 Does the Differentiation State of the Keratinocyte Alter Galvanotaxis? .......... 144 The In’uence of Extracellular Matrix on Keratinocyte Galvanotaxis .............. 145 The Keratinocyte Electrical Compass ............................................................... 146 The Role of the EGFR in Keratinocyte Galvanotaxis ....................................... 146 The Role of cAMP in Keratinocyte Galvanotaxis .............................................147 The Role of Ion Channels in Keratinocyte Galvanotaxis .................................. 148 The Role of Integrins in Keratinocyte Galvanotaxis ......................................... 149 Galvanotaxis of Monolayers of Keratinocytes .................................................. 150 EF-Mediated Changes to Keratinocyte Gene Transcription ............................. 151 Conclusions ....................................................................................................... 151 Acknowledgments ............................................................................................. 151 References ......................................................................................................... 151

The skin is the largest organ in the body, and its outer layer, the epidermis, forms a protective barrier against the external environment, protecting us from a myriad of potentially harmful agents, such as heat and bacterial infections. It is therefore imperative that any damage to the epidermis is repaired as quickly as possible. Consequently, evolution has primed our healing responses to repair wounds rapidly. In’ammatory cells arrive at a wound site within minutes to clear the wound of any infection (see Chapter 8), and sedentary keratinocytes at the wound edge become migratory within a few hours to begin the process of reepithelialization. The exact cues that initiate the changes in keratinocyte morphology and motility are unknown, but chemical, physical, and electrical cues are present at the wound edge.