AQs were tested at 2.5 μM in darkness and under irradiation conditions. They were photoactivated with violet-blue LED (λ = 410 ± 10 nm; fluence rate =50 mW/cm2) and exposure time corresponded to a fluence of 27 J/cm2. Negative and positive control (−C and +C, respectively) were included. Mitochondrial activity was determined by using MTT assay that is a measure of the cell viability and it was expressed as a percentage respect to −C (% CV).
Results showed that AQs in darkness conditions showed similar metabolic activity as −C, except for 5-ClSor (about 75% CV). Under irradiation, AQs exhibited dissimilar results. Sor and 7-ClBisor maintained cell viability at approximately 100%, Bisor and Lyc around 70%, whereas 5-ClSor reduced cell viability by 90%. Taken together, our results suggest that Sor could mediate photodynamic therapy (PDT) in cutaneous infections since no toxicity was observed in fibroblasts. On the other hand, 5-ClSor could be used for topical PDT of keloids and hypertrophic scars.