Monophasic Pulsed Microcurrent of 1-8 Hz Increases the Number of Human Dermal Fibroblasts.

OBJECTIVE: Pressure injuries seriously impact the quality of life of patients and increase public and private healthcare costs. Electrical stimulation therapy is recommended for wound contraction, and some clinical studies have shown that the application of a monophasic pulsed microcurrent can help to reduce the treatment period. However, the optimal stimulus conditions are unclear. The purpose of this study was to investigate the effect of different frequencies of monophasic pulsed microcurrent stimulation on the number and viability of human dermal fibroblasts.
METHODS: Human dermal fibroblasts were electrically stimulated in vitro (intensity: 200 μA; frequency: 1, 2, 4, 8, 16, 32, and 64 Hz; duty factor: 50%) for 1 h three times every 24 h. Controls were unstimulated. Cell numbers and cell viability were assessed after each electrical stimulation session.
RESULTS: In the 1-, 2-, 4-, and 8-Hz groups, cell numbers were significantly higher than those in the control group, whereas electrical stimulation at 64 Hz resulted in a decrease in cell numbers at 24 h after the third treatment (p < 0.05). Cell viability was high in both the control and low-frequency stimulation groups, with no significant differences between groups.
CONCLUSION: Application of 1-8 Hz monophasic pulsed microcurrent stimulation increased the number of human dermal fibroblasts in vitro, and is proposed as the optimal condition for accelerating the healing of pressure injuries. ©2016 The Japanese Association of Rehabilitation Medicine.