Influence of pH on wound-healing: a new perspective for wound-therapy?

Abstract

Wound healing is a complex regeneration process, which is characterised by intercalating degradation and re-assembly of connective tissue and epidermal layer. The pH value within the wound-milieu influences indirectly and directly all biochemical reactions taking place in this process of healing. Interestingly it is so far a neglected parameter for the overall outcome. For more than three decades the common assumption amongst physicians was that a low pH value, such as it is found on normal skin, is favourable for wound healing. However, investigations have shown that in fact some healing processes such as the take-rate of skin-grafts require an alkaline milieu. The matter is thus much more complicated than it was assumed. This review article summarises the existing literature dealing with the topic of pH value within the wound-milieu, its influence on wound healing and critically discusses the currently existing data in this field. The conclusion to be drawn at present is that the wound pH indeed proves to be a potent influential factor for the healing process and that different pH ranges are required for certain distinct phases of wound healing. Further systematic data needs to be collected for a better understanding of the pH requirements under specific circumstances. This is important as it will help to develop new pH targeted therapeutic strategies.

An acidic microenvironment sets the humoral pattern recognition molecule PTX3 in a tissue repair mode

“…8 E and Fig. S2), which suggests cellular metabolic adaptation to trauma-induced tissue hypoperfusion and hypoxia (Schneider et al, 2007). In the z-projection (14 optical sections of 10 µm) of the dermis between the perilesion area and the wound, a significantly higher colocalization (Supplemental material).…”

“…Liver injury. Mice (129/Sv) were injected s.c. with 50 µl/20 g of carbon tetrachloride (CCl 4 ) dissolved in a 1:1 ratio with mineral oil (Sigma-Aldrich), as pH ranging from 5.5 to 6.9 occurs at sites of tissue injury (Schneider et al, 2007) and in growing tumors (Gatenby and Gillies, 2004). The Plg activators uPA and tPA are neutral proteases (Hamilton, 1980) and accordingly, we observed that cellfree fibrinolysis was less effective at acidic pH compared with neutral pH.…”

Modeling and simulation of chemomechanics at the cell-matrix interface

“…In the environment of a tumor or wound bed, it is well established that the extracellular pH can become acidic. [80][81][82] In the tumor environment, the measured pH values range from 5.85-7.68. 81 Early stage wounds have a measured average pH of 5.7-6.1.…”

Miniaturized textile-based multi-layer ph-sensor for wound monitoring applications

“…With this acquired sensory information, possible complications typically resulting from infections of the wound, can be treated promptly so that penetration of pathogens into the body and the bloodstream can be avoided. Inflammation is a complex cellular process that changes the properties of the wound exudate and alters various physiological parameters like; pH [1], temperature [2][3], wound humidity or viscosity [4][5], concentration of various ions (particularly reactive oxygen species) [6][7] and content of lactate [8][9] or urea [10][11]. Therefore, the wound healing process can be assessed by continuous monitoring of one or more properties.…”

“…The pH value plays an important role in the wound healing process and the precise relationship between the pH value and the condition of the wound depends on the wound type. Generally, it can be said that a permanent pH-value higher than 7.5 over a long period, is an indicator of impaired wound healing [1].…”