Comparative efficacy of fractional CO₂ laser combined with concentrated growth factor (CGF) for treating hypertrophic scars in rabbit ears

While fractional CO₂ laser and concentrated growth factor (CGF) have been individually applied in scar management, their combined therapeutic potential remains underexplored. This study aimed to evaluate the synergistic efficacy and underlying mechanisms of fractional CO₂ laser combined with CGF in a rabbit ear hypertrophic scar model, with a focus on inflammatory modulation and collagen remodeling. Hypertrophic scars were induced on both ears of six rabbits. The scars were divided into three groups: combined CO₂ laser + CGF, CO₂ laser + saline, and untreated control. Scar tissues were assessed via macroscopic observation, H&E staining, Masson trichrome staining, and immunohistochemistry for CD34, IL-6, and TGF-β1. The combined treatment group exhibited significantly improved scar appearance, collagen organization, and reduced microvessel density compared to both the laser-only and control groups. Immunohistochemical analysis revealed a marked downregulation of IL-6 and TGF-β1 in the combined group, indicating enhanced anti-fibrotic and anti-inflammatory effects. The combination of fractional CO₂ laser and CGF synergistically promotes scar regression through dual mechanisms of physical ablation and biological regulation. This approach represents a promising strategy for enhancing scar treatment outcomes, with potential for clinical translation.