皮秒激光在皮肤科领域的应用已经从纹身去除扩展到了进行临床皮肤再生。虽然已经阐明了各种色素去除机制，但与皮肤再生相关的分子变化尚未确定。本研究的目的是探讨理论基础，并在小鼠模型中评估使用1064nm分数皮秒激光进行皮肤再生的疗效。我们对年老和年轻的无毛雌性小鼠皮肤进行了体表、组织、显微和电镜评估，使用分数皮秒激光进行了体内研究。在组织学检查中，皮肤表面的地形增强，皮肤厚度增加。电镜检查显示，上皮性纤维束错乱，微空间和血管泄漏。分数皮秒激光治疗后，胶原合成标志物和各种炎症细胞因子水平升高，如前胶原、白细胞介素-1β、肿瘤坏死因子-α和热休克蛋白。本研究提供了先前在临床观察中报道的分数皮秒激光皮肤再生效应的可能机制。根据我们的发现，分数皮秒激光可以广泛应用于需要皮肤再生和推广的临床设置。©2022 Wiley Periodicals LLC。

Application of the picosecond laser in the field of dermatology has expanded from tattoo removal to skin rejuvenation on a clinical basis. Although various mechanisms of pigment removal have been elucidated, the molecular changes associated with skin rejuvenation have yet to be identified. The aim of this study was to explore the theoretical basis and to evaluate the efficacy of skin rejuvenation using a 1064-nm fractional picosecond laser in a mouse model.We conducted an in vivo study using a fractional picosecond laser on the skin of old and young female hairless mice and performed topographical, histological, micro-, and electron microscopic assessments.The topography of the skin surface was enhanced and showed increased dermal thickness on histological examination. Electron microscopy revealed disarranged collagen bundles with microspaces and vascular leakage in the upper dermis. Levels of collagen synthesis markers and various inflammatory cytokines, such as procollagens, interleukin-1β, tumor necrosis factor-α, and heat shock proteins, were elevated in the laser-treated skin.This study provides a possible mechanism for the skin rejuvenation effect of fractional picosecond laser that has been reported previously in clinical observations. Based on our findings, the fractional picosecond laser could be widely applied in clinical settings where dermal regeneration and promotion of skin rejuvenation is required.© 2022 Wiley Periodicals LLC.