Antifungal Activity of Magnesium Oxide Nanoparticles: Effect on the Growth and Key Virulence Factors of Candida albicans

The aim of this research was to study the effects of different concentrations of magnesium oxide nanoparticles (MgO NPs) on the growth and key virulence factors of Candida albicans (C. albicans). The minimum inhibitory concentration (MIC) of MgO NPs against C. albicans was determined by the micro-broth dilution method. A time-kill curve of MgO NPs and C. albicans was established to investigate the ageing effect of MgO NPs on C. albicans. Crystal violet staining, the MTT assay, and inverted fluorescence microscopy were employed to determine the effects of MgO NPs on C. albicans adhesion, two-phase morphological transformation, biofilm biomass, and metabolic activity. The time-kill curve showed that MgO NPs had fungicidal and antifungal activity against C. albicans in a time- and concentration-dependent manner. Semi-quantitative crystal violet staining and MTT assays showed that MgO NPs significantly inhibited C. albicans biofilm formation and metabolic activity, and the difference was statistically significant (p < 0.001). Inverted fluorescence microscopy showed that MgO NPs could inhibit the formation of C. albicans biofilm hyphae. Adhesion experiments showed that MgO NPs significantly inhibited the initial adhesion of C. albicans (p < 0.001). This study demonstrates that MgO NPs can effectively inhibit the growth, initial adhesion, two-phase morphological transformation, and biofilm formation of C. albicans and is an antifungal candidate.