Iontophoresis of treprostinil promotes wound healing in a murine model of scleroderma-related ulcers.

OBJECTIVE: Systemic sclerosis (SSc) is a rare, chronic disease characterized by fibrosis, vascular alterations and digital ulcerations. Few drugs have shown efficacy to enhance wound healing of existing SSc-related ulcers. Local delivery of treprostinil, a prostacyclin analogue, may improve wound healing. The present work aimed first at developing a mouse model of SSc-related ulcerations and second at assessing the effect of iontophoresis of treprostinil on wound healing. METHODS: We used two murine models of SSc: chemically induced with HOCl, and urokinase-type plasminogen activator receptor (uPAR)-deficient. Excisional wounding was performed on the dorsal midline with a biopsy punch. Animals were randomized into three groups: treated with electrostimulation alone, with treprostinil iontophoresis or untreated. We assessed wound healing over time, as well as skin microvascular reactivity, inflammation, microvessel density and collagen distribution, before wounding and after re-epithelialization. RESULTS: uPAR-/- mice, but not HOCl-treated mice, showed impaired wound healing and decreased microvascular reactivity compared with their controls. Treprostinil iontophoresis improved wound healing and microvascular density and decreased inflammation in uPAR-/- mice, while electro-stimulation did not. However, treprostinil had no effect on microvascular reactivity and collagen distribution. CONCLUSION: This study suggests that excisional wounds in uPAR-/- mice are a relevant model of SSc-related ulcers. In addition, treprostinil iontophoresis enhances wound healing in this model. Further work in now needed to show whether this effect translates in humans.

Hierarchical evaluation of electrical stimulation protocols for chronic wound healing: An effect size meta-analysis.

Electrical stimulation (ES) has been tested for decades to improve chronic wound healing. However, uncertainty remains on the magnitude of the efficacy and on the best applicable protocol. We conducted an effect size meta-analysis to assess the overall efficacy of ES on wound healing, to compare the efficacy of the different modalities of electrical stimulation, and to determine whether efficacy differs depending on the wound etiology, size, and age of the chronic wound. Twenty-nine randomized clinical trials with 1,510 patients and 1,753 ulcers were selected. Overall efficacy of ES on would healing was a 0.72 SMD (95% CI: 0.48, 1) corresponding to a moderate to large effect size. We found that unidirectional high voltage pulsed current (HVPC) with the active electrode over the wound was the best evidence-based protocol to improve wound healing with a 0.8 SMD (95% CI: 0.38, 1.21), while evaluation of the efficacy of direct current was limited by the small number of studies. ES was more effective on pressure ulcers compared to venous and diabetic ulcers, and efficacy trended to be inversely associated with the wound size and duration. This study confirms the overall efficacy of ES to enhance healing of chronic wounds and highlights the superiority of HVPC over other type of currents, which is more effective on pressure ulcers, and inversely associated with the wound size and duration. This will enable to standardize future ES practices.