Evaluation of fractional photothermolysis effect in a mouse model using nonlinear optical microscopy

Abstract

Fractional photothermolysis (FP) induces discrete columns of photothermal damage in skin dermis, thereby promoting collagen regeneration. This technique has been widely used for treating wrinkles, sun damage, and scar. In this study, we evaluate the potential of multiphoton microscopy as a noninvasive imaging modality for the monitoring of skin rejuvenation following FP treatment. The dorsal skin of a nude mouse underwent FP treatment in order to induce microthermal zones (MTZs). We evaluated the effect of FP on skin remodeling at 7 and 14 days after treatment. Corresponding histology was performed for comparison. After 14 days of FP treatment at 10 mJ, the second harmonic generation signal recovered faster than the skin treated with 30 mJ, indicating a more rapid regeneration of dermal collagen at 10 mJ. Our results indicate that nonlinear optical microscopy is effective in detecting the damaged areas of MTZ and monitoring collagen regeneration following FP treatment.

Effects of the lower energy and pulse stacking in carbon dioxide laser skin treatment: an objective analysis using second harmonic generation

“…Due to the collagen non-centrosymmetric molecular structure, it is an effective SHG generator 41 . The images obtained from SHG can be used to provide information on collagen structure within the skin 42 . Guo 43 used SHG to investigate skin rejuvenation after treatment with a 1550 µm fractional laser.…”

“…The images obtained from SHG can be used to provide information on collagen structure within the skin 42 . Guo 43 used SHG to investigate skin rejuvenation after treatment with a 1550 μm fractional laser. They concluded that it is an appropriate technique to evaluate collagen regeneration by the fractional laser treatment.…”

“…Even the molecular mechanisms underlying fractional CO 2 laser clinical outcomes were already studied 36 . The use of SHG signal to evaluate collagen responses to laser treatments was already studied by some authors 43 , 44 .…”