Liposomal Methylglyoxal Targets Virulence and Intracellular Persistence to Overcome Amphotericin B Resistance in Cryptococcus neoformans.

Cryptococcosis, caused by Cryptococcus neoformans, remains a major cause of mortality in immunocompromised patients, with treatment increasingly limited by resistance and toxicity associated with Amphotericin B (Amp B). In this study, methylglyoxal (MG) was evaluated as a virulence-targeted antifungal strategy, with emphasis on its liposomal delivery. MG exhibited superior antifungal activity as compared to Amp B, demonstrating lower MIC values and significantly enhanced inhibition of biofilm formation and laccase activity, key determinants of cryptococcal pathogenicity. Notably, MG showed potent intracellular antifungal activity within macrophages, where C. neoformans persists. Liposomal MG (Lip-MG) markedly reduced macrophage-associated fungal burden under the tested conditions, markedly outperforming both free MG and Amp B formulations. In a leukopenic mouse model of systemic infection, liposomal MG significantly improved survival (up to ~70%) and reduced pulmonary fungal burden as compared to Amp B, which showed limited therapeutic benefit. Importantly, MG-based formulations exhibited a favorable safety profile, with significantly lower nephrotoxicity than Amp B. Collectively, these findings demonstrate that Lip-MG acts through a dual virulence-targeted activity mechanism while effectively eliminating intracellular infection. This dual action, combined with improved safety, highlights MG-based nanotherapy as a promising and translational alternative for the treatment of drug-resistant cryptococcosis.