Photodynamic Effects of Topical Photosensitizer, Photodithazine Using Micro-LED for Acne Bacteria Induced Inflammation.

Background: Photodynamic therapy (PDT) using topical photosensitizers has been widely used worldwide as a therapeutic modality for acne. However, there are no published reports on photodithazine PDT for acne treatment.

Objective: We investigated the effectiveness of PDT with photodithazine and micro-LED treatment for acne bacteria-induced inflammation.

Methods: We established an acne bacteria-induced inflammation model by injecting of Cutibacterium acnes into the backs of HR-1 mice. The mouse models were divided into seven groups for control and comparison. Topical photosensitizer (photodithazine) was administered to the mice, and then their acne lesions were exposed to a micro-light-emitting diode (micro-LED) source. The effectiveness of the treatment on acne lesions was evaluated through clinical findings and measurements of acne inflammation biomarkers using semi-quantitative reverse transcription polymerase chain reaction, and Western blot. Additionally, hematoxylin and eosin staining and immunohistochemical staining were employed to evaluate the changes in inflammatory cells and biomarkers in skin tissues.

Results: Compared with the control groups treated with either LED or photosensitizer alone, the acne lesions were significantly reduced in severity and number after PDT. The mRNA and protein levels of biomarkers (interleukin [IL]-1α, IL-1β, tumor necrosis factor-α, Toll-like receptor 2, matrix metalloproteinase-2, and IL-8) exhibited variable decreases in the PDT group relative to the others. Moreover, there was a decline in inflammatory cells and biomarkers in skin specimens after PDT.

Conclusion: This in vivo study demonstrated that PDT using photodithazine and micro-LED technology is effective against inflammation induced by acne bacteria.