**4. Discussion**

Pressure ulcers, also called bedsores or decubitus ulcers, develop when there is too much unrelieved pressure on the skin in combination with shear and/or friction. They form typically over a bony prominence, leading to ischemia, cell death and tissue necrosis [23,24]. They are more common in bedridden patients, a ffecting their quality of life, morbidity and mortality. Once a pressure ulcer develops, not only does it cause pain and discomfort, but it may lead to complications such as infection, like meningitis, cellulitis and endocarditis, with the potential for sepsis and death [25]. The shoulder blades, tailbone, elbows, heels and hips are the most common sites for bed sores because these areas contain little muscle and fat [26]. The development of a pressure ulcer can interfere with functional recovery, promote social isolation, and contribute to excessive length of hospital stay [27]. As a consequence, they have been described as one of the costliest and physically devastating complications [28,29], and they are the third most expensive disorder after cancer and cardiovascular diseases [30].

Treatment of pressure ulcers involves multiple methods intended to alleviate the conditions contributing to ulcer development (support surfaces, repositioning and nutritional support), protection of the wound from contamination, and the creation of a clean wound environment, promotion of tissue healing (local wound applications, debridement and wound cleansing), adjunctive therapies, as well as consideration for surgical treatment [31]. Understanding the function of bioelectricity in wound healing o ffers a possibility for the therapeutic implementation of ES, especially when natural regeneration mechanisms have been paused. ES is a well-proven technique for the therapy of chronic wounds [32]. Its application for the treatment of wounds adopts the physiological fact that skin and epithelia act as batteries and have electric potentials.

When a wound occurs in the epithelium, there is an electrical leak that short-circuits the skin, enabling the current to flow out of the wound, resulting in the current of injury. This leak of current provides signals for the migration of the epithelia into the wound, initiating a physiological endogenous regeneration processes [32–34]. Disruption of these physiological electric fields and ionic currents alters normal organ development, tissue regeneration, and thus, proper wound healing [35–37].

Our team has previously experimented on WMCS, an innovative modality of traditional electrode-based ES, and we have particularly shown recently that WMCS can be an e ffective method of diabetic-related wound care [22], for di fficult to treat chronic wounds [20], for firework burns [38], as well as for Martorell's ulcer [39]. Tissue potentials and currents generated by either electrode-based ES or WMCS seem to be the determinant factor which initially drives the beneficial clinical outcomes of these two similar, but distinct, techniques.

In this report, based upon clinical as well as on immunohistochemical evidences, we further report on WMCS treatment with two single case reports of distinct pathologies. Our results showed that WMCS aids the wound healing of pressure ulcers by restoring the natural current of injury, thus, reinitiating the body's tissue physiological regeneration mechanisms. Notably, WMCS suppresses inflammatory reactions by reducing granulocyte aggregation, followed by stimulating myofibroblastic activity and collagen fiber formation. These results are in accordance, not only with our previous clinical observational studies, but also to others, who have e ffectively used similar ES modalities to treat pressure ulcers [40–42]. In addition, several recent systematic reviews provide positive recommendation regarding the e ffectiveness of ES to increase wound healing [43–48]. Consequently, based on literature as well as on our previous work, WMCS o ffers a unique treatment option to chronic and non-healing wounds of diverse etiopathology. WMCS in particular, is believed to aid in wound healing by imitating and restoring the natural electrical current that is been disrupted in injured skin.
