Sunflower Oil and Cholesterol Nanoemulsion: A Novel Carrier for Micafungin to Combat Multi-Resistant Candida auris

Candida auris is an emerging, multidrug-resistant yeast that causes systemic infections, mainly in hospitalized or immunosuppressed patients. This pathogen has a high mortality and morbidity rate. This study aims to evaluate the antifungal potential of micafungin (MICA) encapsulated in a nanoemulsion (NEM) against four clades of C. auris and other non-C. auris species. The antifungal potential of MICA and NEM was evaluated by determining mature biofilm inhibition (0.78-50 µg/mL). The antifungal activities of MICA and NEM (5.92 mg/Kg) were evaluated using an in vivo model of Galleria mellonella. The results showed that NEM intensified the antibiofilm action of MICA, especially in 48 h mature biofilms. In vivo results displayed a higher effectiveness of NEM against all clades of C. auris tested, inhibiting the fungal load in the hemolymph and tissues of G. mellonella with a difference of 3 log10. In addition, C. auris infection caused granulomas surrounded by hemocytes, mainly at the lower and upper ends. Conversely, C. albicans developed pseudohyphae, biofilms, filaments, and chlamydospores. In conclusion, encapsulation of MICA in a nanoemulsion enhances its antifungal activity against mature biofilms of C. auris. This strategy may be considered a therapeutic approach for the control of infections and the dissemination of this new global health threat.