Pulsed lasers at the near infrared (NIR) range have been widely used in dermatology. Ultrashort pulsed picosecond lasers are found with the specific ability of very effective activation of skin repair and remodeling along with significant photodamage. Femtosecond lasers, with a shorter pulse width, may be a promising alternative to current NIR lasers in clinic. In this study, we performed optical micromachining by a femtosecond laser at 1,030 nm to skin of live mice in two modes of scanning of focused laser and direct irradiation by unfocused laser. The acute and one-day delayed immune molecular responses of the skin to the micromachining are studied by immunofluorescence microscopy of the skin sections. Our data shows the focused laser can activate remodeling of skin without any significant immune responses. In contrast, the direct irradiation by the unfocused laser activate significant immune responses in the deep dermis with high regulation of interleukin. Those results suggest focused femtosecond laser is of good promising potential in activation of skin remodeling and repairing with little immune or physical damage.

近红外（NIR）范围的脉冲激光已在皮肤病学中广泛使用。发现超短脉冲皮秒激光器具有非常有效地激活皮肤修复和重塑以及明显的光损伤的特定能力。飞秒激光具有更短的脉冲宽度，可能是目前临床上近红外激光的有希望的替代品。在这项研究中，我们以1030 nm的飞秒激光对活小鼠的皮肤进行了光学微加工，采用聚焦激光扫描和非聚焦激光直接照射两种模式。通过皮肤切片的免疫荧光显微镜研究了皮肤对微加工的急性和一日延迟免疫分子反应。我们的数据表明，聚焦激光可以激活皮肤重塑而没有任何明显的免疫反应。相比之下，未聚焦激光的直接照射激活了深层真皮中的大量免疫反应，并高度调节了白介素。这些结果表明，聚焦飞秒激光在激活皮肤重塑和修复方面具有良好的潜力，而对免疫或身体的损害很小。