Answer:
In PRS 89:891, 1992, “Enhanced healing of cutaneous wounds in rats using beads with positively charged surfaces,” Mustoe et al report that wounds treated with positively charged particles were 53% stronger than controls, and characterized histologically by large quantities of collagen-rich connective tissue. However, by 94 days, no difference in wound strength versus control were noted.
In Annals 27:265, 1991, “Electrical nerve stimulation improves healing of diabetic ulcers,” the authors reports the use of ENS for 20 minutes twice daily for 12 weeks. They found significant improvement in both ulcer area and number of healed ulcers in the group receiving ENS compared to placebo controls.