Evaluation of photodynamic therapy against polymicrobial acne biofilms: a preclinical study

Author(s)

Sarah Raquel De Annunzio

• Document type: Doctoral Thesis
• Press: Araraquara. 0000-00-00.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Farmacêuticas. Araraquara
• Defense date: 2022-05-25
• Advisor: Carla Raquel Fontana; Juliana Cabrini Carmello

Abstract

Acne vulgaris is one of the most common dermatological diseases encountered in clinical practice. The treatment options for this dermatosis are diverse, but they are not always effective. Microbial resistance to antibiotics and the adverse effects of conventional therapies have led researchers to investigate alternative treatments. Thus, this study aimed to evaluate the action of photodynamic therapy (PDT) mediated by curcumin, methylene blue and chlorin-e6 on bacterial biofilms from patients with acne vulgaris. One to four photodynamic applications were performed on the biofilms and the identification of microorganisms present in the samples was performed by conventional PCR, by gene amplification with species-specific primers. The biocompatibility of the treatments was evaluated in a three-dimensional (3D) skin co-culture model. The microorganisms identified in the clinical samples were Cutibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus. The results showed that PDT mediated by methylene blue was able to completely eliminate cells from acne biofilms after three applications, while PDT mediated by curcumin and chlorin-e6, although they showed significant reductions, did not completely eliminate cells from biofilms even after four photodynamic applications. Thus, the success of consecutive applications may be dependent on the photosensitizer. Biocompatibility assays showed that PDT mediated by the three photosensitizers significantly reduced cell viability in the 3D skin culture model and this effect may be dependent on the fluence used. Taken together, the results obtained in this study revealed that the three photosensitizers studied may be promising for the development of efficient clinical protocols in the treatment of acne vulgaris. (AU)

• FAPESP's process: 18/09088-1 - Assessment of photodynamic therapy against polymicrobial acne biofilms: a preclinical study
• Grantee: Sarah Raquel de Annunzio
• Support Opportunities: Scholarships in Brazil - Doctorate