Abstract: Objective To study the impact of non-ablative laser rejuvenation on the transepidermal water loss of murine skin. Methods A Cooltouch Ⅱ 1 320 nm laser, Gentlelase 755 nm laser, Vbeam 595 nm laser and GentleYAG 1 064 nm laser were used to irradiate murine bark skin. In the GentleYAG 1 064 nm laser group, 1% sodium hyaluronate (SH) was used to treat murine skin following laser treatment. Skin transepidermal water loss (TEWL) and water content of the skin were measured at 1 h, 3 h, 6 h, 9 h, 12 h, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, and 7 d after laser treatment. Results Skin TEWL significantly increased as early as 1 h after laser treatment (P<0.05), and recovered on day 7 after laser treatment in the 595nm laser group, on day 2 in the 1320 nm laser group, on day 4 in the 1 064 nm laser and 755 nm laser group, as well as on day 4 in 1 064 nm laser group with additional 1% SH treatment (all P>0.05). Conclusions Although each of the various forms of non-ablative laser rejuvenation investigated in this study can induce an abnormal increase of skin TEWL, the TEWL recovers within 1 week. The recovery of skin TEWL in the 595 nm laser group is slower than that in the 1 320 nm laser group, which may be caused by the difference in the wavelengths. After laser treatment, SH (1%) confers no benefit upon skin TEWL recovery.

Key words: Lasers, Hyaluronic acid, Transepidermal water loss