摘要

Objectives: To develop and validate a standardized human in-vivo platform using micro-lens-array (MLA)–focused picosecond laser–induced optical breakdown (LIOB) as a reproducible dermal micro-injury model for evaluating skin-regeneration responses and assessing topical interventions. Introduction: Personalized human injury models are essential for confirming skin-regeneration process and for assessing the efficacy of different topical therapies. MLA-focused picosecond LIOB creates subsurface cavitation points without epidermal ablation, offering a controlled method to investigate inflammation and early repair mechanisms. A standardized in-vivo model may improve consistency in clinical research and device-based dermatologic evaluation. Materials / method: Low-fluence picosecond irradiation (1064 nm, 2.1 J/cm², 6-mm spot, five pulses) was applied to generate uniform subsurface vacuoles. Sequential imaging under white, polarized, and UV light documented inflammatory and structural changes. Skin-parameter analysis (hydration, oil level, elasticity, brightness) and occlusive dressing observation were used to quantify epidermal recovery and dermal response over time. Results: MLA-induced LIOB produced consistent dermal micro-injuries with predictable erythema and inflammatory signatures on polarized-light imaging. UV fluorescence highlighted focal inflammatory activity, while white-light imaging showed surface-texture alteration. Serial evaluations demonstrated progressive improvement in hydration, barrier recovery, and dermal uniformity over two weeks. The model showed strong reproducibility and sensitivity to post-treatment changes. Conclusion: This human in-vivo LIOB platform provides a controlled and quantifiable micro-injury model for assessing wound-healing mechanisms and topical therapeutic strategies. Its ability to standardize injury depth, visualize inflammatory progression, and measure multidimensional skin-recovery parameters supports its application in clinical research and future dermatologic innovation.