Using light to treat fungal infections: photodynamic therapy as an alternative technology to overcome candidiasis

Candidiasis is the 7th most common bloodstream infection in Brazilian hospitalized patients and represents 74% of serious fungal infections in Brazil. Superficial forms of candidiasis can lead to disfiguration, disability, and can potentially become systemic and lethal.

There is a limited number of antifungal drugs available and the unpaired increase of antifungal resistance highlights the urge to develop alternative technologies to treat fungal infections.

Photodynamic inactivation(PDI) has been suggested as a promising antimicrobial technology, and no microbial resistance has been described against it. PDI uses light to produce reactive oxygen species and destroy pathogenic cells.

Our group has been investigating the effect of PDI on Leishmania spp. and yeast-forms of Candida albicans using zinc porphyrins (ZnP). The organization of Candida in biofilms grants it a higher resistance to antifungals, including PDI.

The association of PDI with metallic nanoparticles (ZnP-NP) has been suggested to improve the photodynamic efficiency in biofilms.

We propose to develop a protocol to apply ZnP and ZnP-NP PDI for planktonic cells and biofilms of C. albicans and C. glabrata.

The establishment of this technology to treat candidiasis will decrease the exposure of patients to antifungal drugs, preventing the emergence of new resistant Candida strains.