Wound pH depends on actual wound size

Wound healing is an intricate process that involves many types of cells, reaction pathways as well as chemical, physical and electrical cues. Since biochemical reactions and physiological events are pH-dependent we study here pH as an important major characteristic of the wound healing process in the presence of endogenous and exogenous electric fields. Our model gives the spatial pH distribution in a wound. In particular we isolate a number of dimensionless quantities which sets the length, energy and time scales governing the wound healing process and which can be experimentally tested. Most interesting finding is that wound pH depends on actual wound size. pH in wounds pH in wounds pH in wounds pH in wounds As a consequence of a tissue trauma resulting in a wound, a set of delicate processes are initiated to restore homeostasis in the damaged area. Wound healing is a field of study that must have a history as long as that of mankind. Some aspects of the healing process are rather well studied and understood by now. Due to the complexity of the process there are however many that remain yet uncharted or unappreciated. The shortcomings in our understanding are reflected in wound care where impaired wound healing and chronic wounds still are a major problem that in total have immense social and economic consequences and ultimately challenges us to design new sensing, imaging and treatment techniques [1,2]. Our contribution here is aimed at the spatial monitoring of pH in a wound, relating this pH distribution to the underlying processes taking place. We also apply an external field which can affect the distribution of charges and charged objects in a wound in competition with the endogenous electric fields which are generated in all wound healing processes. The pH of a wound is an aspect of the healing process that until recently has been given little attention. This although it is long known that biochemical processes and other physiological events are sensitive to the pH value of the environment [3,4]. During the last decades it has been shown that the wound healing process is associated with a spatiotemporal change in pH in the wounded area [5,6]. Such pH-profiles of wounds healing in a normal fashion are significantly different from those associated with healing processes in chronic wounds [6]. However a realistic description as well as a theoretical understanding of the spatiotemporal