Angiogenesis is induced and wound size is reduced by electrical stimulation in an acute wound healing model in human skin.

Angiogenesis is critical for wound healing. Insufficient angiogenesis can result in impaired wound healing and chronic wound formation. Electrical stimulation (ES) has been shown to enhance angiogenesis. We previously showed that ES enhanced angiogenesis in acute wounds at one time point (day 14). The aim of this study was to further evaluate the role of ES in affecting angiogenesis during the acute phase of cutaneous wound healing over multiple time points. We compared the angiogenic response to wounding in 40 healthy volunteers (divided into two groups and randomised), treated with ES (post-ES) and compared them to secondary intention wound healing (control). Biopsy time points monitored were days 0, 3, 7, 10, 14. Objective non-invasive measures and H&E analysis were performed in addition to immunohistochemistry (IHC) and Western blotting (WB). Wound volume was significantly reduced on D7, 10 and 14 post-ES (p = 0.003, p = 0.002, p<0.001 respectively), surface area was reduced on days 10 (p = 0.001) and 14 (p<0.001) and wound diameter reduced on days 10 (p = 0.009) and 14 (p = 0.002). Blood flow increased significantly post-ES on D10 (p = 0.002) and 14 (p = 0.001). Angiogenic markers were up-regulated following ES application; protein analysis by IHC showed an increase (p<0.05) in VEGF-A expression by ES treatment on days 7, 10 and 14 (39%, 27% and 35% respectively) and PLGF expression on days 3 and 7 (40% on both days), compared to normal healing. Similarly, WB demonstrated an increase (p<0.05) in PLGF on days 7 and 14 (51% and 35% respectively). WB studies showed a significant increase of 30% (p>0.05) on day 14 in VEGF-A expression post-ES compared to controls. Furthermore, organisation of granulation tissue was improved on day 14 post-ES. This randomised controlled trial has shown that ES enhanced wound healing by reduced wound dimensions and increased VEGF-A and PLGF expression in acute cutaneous wounds, which further substantiates the role of ES in up-regulating angiogenesis as observed over multiple time points. This therapeutic approach may have potential application for clinical management of delayed and chronic wounds.

Electrical stimulation increases blood flow and haemoglobin levels in acute cutaneous wounds without affecting wound closure time: evidenced by non-invasive assessment of temporal biopsy wounds in human volunteers.

Recent studies highlighted the beneficial effects of a novel electrical stimulation waveform, the degenerate wave (DW), on skin fibroblasts and symptomatic skin scarring. However, no study to date has investigated the role of DW on acute cutaneous wounds. Therefore, we evaluated this in a trial using a temporal punch biopsy model. Twenty healthy volunteers had a biopsy performed on day 0 (left arm) and day 14 (right arm). On day 14, DW was applied. Participants were randomised into two groups. Objective non-invasive assessments were performed on days 0, 7, 14, 60 and 90 using spectrophotometric intracutaneous analysis and full-field laser perfusion imaging. There were statistically significant increases in mean flux on day 14 (P = 0.027) in the post-DW arm. Haemoglobin levels increased on day 7 for the post-DW arm compared to without DW (P = 0.088). Differences in melanin levels were higher post-DW on the left arm between randomised groups on day 90 (P = 0.033). Haemoglobin levels in the vascular ring increased significantly from day 7 to 90 (P < 0.001 for post-DW and without DW arms). This study, for the first time, shows that DW increases blood flow and haemoglobin levels in acute healing wounds without affecting wound closure time and may have potential application in enhancing acute cutaneous healing.