In vitro evaluation of the cis-[Ru(phen)(pPDIp)] complex for antimicrobial photodynamic therapy against Sporothrix brasiliensis and Candida albicans.

BACKGROUND

Photodynamic therapy (PDT) activates a photosensitizer by visible light to generate cytotoxic oxygen species that lead to cell death. With proper illumination, PDT is often used in applications on superficial and sub-surface lesions. Sporotrichosis infection occurs by Sporothrix fungi which causes a skin wound, worsened by Candida albicans infections. This study investigated the photosensitizing efficiency of the Ru(phen)(pPDIp)(PF) complex, RupPDIp, against S. brasiliensis and C. albicans.

MATERIAL AND METHODS

RupPDIp efficiency against these fungi was tested using 450 nm (blue light and 36 J/cm) and 525 nm (green light, 25.2 J/cm) at 0.05-20 μM concentrations. To ensure PDT effectiveness, control groups were tested in the absence and in the presence of RupPDIp under light irradiation and in the dark.

RESULTS

RupPDIp eliminated both fungi at ≤5.0 μM. Green light showed the best results, eliminating S. brasiliensis and C. albicans colonies at RupPDIp 0.5 μM and 0.05 μM, respectively.

CONCLUSION

RupPDIp is a promising photosensitizer in aPDT, eliminating 10 CFU/mL of both fungi at 450 nm and 525 nm, with lower light doses and concentrations when treated with the green light compared to the blue light.