Therapeutic effect of low-level 10,600 nm CO2 ablative fractional laser and 1565 nm non-ablative fractional laser on the full-thickness skin wound in a rabbit model

Low-energy fractional laser has been reported conducive to wound healing. This study aimed to compare the effects of 10,600 nm ablative fractional CO₂ laser (AFL) and 1565 nm non-ablative fractional laser (NAFL) on the healing of excisional wounds. Intact rabbit skin was irradiated by AFL or NAFL at different energy levels to observe the postoperative recovery and determine the laser parameters. Subsequently, full-layer skin defects were created, and the skin adjacent to the wound was irradiated by AFL or NAFL. After 1, 2, and 3 weeks of laser treatment, the animals were sacrificed, and the samples were harvested for histological analysis. The skin injury caused by low-energy lasers was recovered within 3 days, while that caused by high-energy lasers took 7 days. So AFL energy was 2.5 mJ, and NAFL was 10 mJ. Wounds treated with AFL had the highest rate of wound closure. At weeks 1 and 2, both lasers increased dermis thickness and vessel density, enhanced collagen deposition, and generally elevated immunoreactivity of Ki-67, α-SMA, TGF-β1, and VEGFA. At week 3, NAFL induced less expression of α-SMA and a higher expression of COL-III relative to COL-I. Summarily, the application of low-energy fractional lasers accelerates the healing of the rabbit wound model, which is related to fibroblast activation, collagen deposition, and the expression of TGF-β1 and VEGFA. Additionally, NAFL may improve the quality of scars after wound healing.