Biomolecular Changes Upon Ablative Laser Therapy of the Skin: A Scoping Review

ABSTRACT Ablative laser therapy is an interventional dermatological tool mainly used for removal of skin lesions, skin rejuvenation and scar treatment. The biomolecular changes following laser therapy are yet not fully understood. This scoping review provides an overview of the molecular changes upon (fractional) ablative laser therapy. Pubmed, Embase and Web of Science were systematically searched, focusing on changes in gene and protein expression. In total, 20 studies were included, involving a variety of laser devices (10,600 nm CO 2 laser, 2940 nm Er:YAG laser, 2790 nm Er:YSGG laser). Most studies concerned ablative laser therapy for skin rejuvenation. Both fractional and full ablative laser induced a wound‐healing response with dermal remodeling and neocollagenesis, characterized by an increase in metalloproteinases and collagen. The inflammatory phase was more pronounced after ablative laser compared to fractional therapy, with more pronounced expression of innate immune‐related genes. High collagen type I, III, VII protein levels persisted for 6 months following both full and fractional ablative laser. Old elastic fibers were degraded by laser therapy, followed by formation of new elastic fibers, as indicated by tropoelastin increase. Elastogenesis was more pronounced after full ablation. Interestingly, Er:YAG minipeels, ablating the epidermis while preserving the basal membrane, showed similar biomolecular changes compared to full ablation of the epidermis and superficial dermal layer.