Optimization of Impedance Spectroscopy Techniques for Measuring Cutaneous Micropore Formation after Microneedle Treatment in an Elderly Population

ABSTRACT Purpose The objective of this study was to optimize a reproducible impedance spectroscopy method in elderly subjects as a means to evaluate the effects of microneedles on aging skin. Methods Human volunteers were treated with microneedles at six sites on the upper arm. Repeated impedance measurements were taken pre- and post-microneedle insertion. Two electrode types were evaluated (dry vs . gel), using either light or direct pressure to maintain contact between the electrode and skin surface. Transepidermal water loss (TEWL) was measured as a complementary technique. Results Five control subjects and nine elderly subjects completed the study. Microneedle insertion produced a significant decrease in impedance from baseline in all subjects ( p