Fatty acid potassium improves human dermal fibroblast viability and cytotoxicity, accelerating human epidermal keratinocyte wound healing in vitro and in human chronic wounds

Effective cleaning of a wound promotes wound healing and favours wound care as it can prevent and control biofilms. The presence of biofilm is associated with prolonged wound healing, increased wound propensity to infection, and delayed wound closure. Anionic potassium salts of fatty acids are tested with commonly used anionic surfactants, such as sodium laureth sulphate (SLES) and sodium lauryl sulphate/sodium dodecyl sulphate (SLS/SDS). The normal human dermal cells demonstrated significantly greater viability in fatty acid potassium, including caprylic acid (C8), capric acid (C10), lauric acid (C12), oleic acid (C18:1), and linoleic acid (C18:2), than in SLES or SLS after a 24‐hour incubation. Cytotoxicity by LDH assay in a 5‐minute culture in fatty acid potassium was significantly lower than in SLES or SLS. in vitro wound healing of human epidermal keratinocytes during the scratch assay in 24‐hour culture was more significantly improved by fatty acid treatment than by SLES or SLS/SDS. In a live/dead assay of human epidermal keratinocytes, C8K and C18:1K demonstrated only green fluorescence, indicating live cells, whereas synthetic surfactants, SLES and SLS, demonstrated red fluorescence on staining with propidium iodide, indicating dead cells after SLES and SLS/SDS treatment. Potassium salts of fatty acids are useful wound cleaning detergents that do not interfere with wound healing, as observed in the scratch assay using human epidermal keratinocytes. As potassium salts of fatty acids are major components of natural soap, which are produced by natural oil and caustic potash using a saponification method, this may be clinically important in wound and peri‐wound skin cleaning. In human chronic wounds, natural soap containing fatty acid potassium increased tissue blood flow based on laser speckle flowgraphs after 2 weeks (P < .05), in addition to removing the eschars and debris. Wound cleansing by natural soap of fatty acid potassium is beneficial for wound healing.