P278 : Nonablative fractional laser as a tool to facilitate skin penetration of 5-aminolevulinic acid with minimal skin disruption

Background: Effective penetration of photosensitizer is an essential step in photodynamic therapy (PDT). There have been trials of several methods, including laser treatment, to facilitate prompt and sufficiently deep transdermal drug delivery. Objectives: This study was performed to evaluate the effects of nonablative fractional laser pretreatment on aminolevulinic acid (ALA) penetration of the skin. Methods: Twelve identical treatment areas of 1 × 1 cm2 on the backs of 10 healthy male subjects were mapped. Each area received laser treatment with a different energy and incubation with ALA for different times. Laser treatment was performed with a 1550 nm fractional erbium glass laser, and the laser energy was set to 20 and 50 mJ with a spot density of 50/cm2. ALA incubation time was set to 30, 60, or 180 min. Porphyrin fluorescence was measured. Results: Nonablative fractional laser-pretreated areas showed significantly increased porphyrin fluorescence compared to non-pretreated areas. Laser energy strength and ALA incubation time were positively correlated with ALA absorption. Conclusion: Nonablative fractional laser treatment effectively enhanced ALA skin penetration. Pretreatment with a nonablative fractional laser can be used for ALA-PDT to achieve higher therapeutic efficacy and shortened ALA incubation times with minimal skin barrier disruption compared to ablative laser.