Echinocandins have an alternative mode of action on biomimetic membranes that is not directly related to the functioning of (1,3) beta-glucan synthase.

Echinocandins are the preferred agents for treating invasive candidiasis; however, rising resistance in Candida species poses a significant challenge for patient care. This study aimed to improve the efficacy of echinocandins against clinical Candida isolates by enhancing their noncanonical membrane activity. The mechanisms of action of anidulafungin, caspofungin, and micafungin on lipid membranes were investigated using a range of biophysical methods and molecular dynamics approaches. Antifungal activity was assessed using a panel of clinical Candida isolates. The results indicated that echinocandins exhibit greater selectivity for ergosterol-containing membranes than for cholesterol-enriched membranes. Echinocandins caused differential phase disordering, leading to a significant increase in the size of sterol-rich ordered domains, induced membrane stress/perturbation, and promoted the formation of ion-permeable transmembrane pores. The membrane activity of echinocandins was enhanced upon incorporation into liposomes. Echinocandin liposomes exhibited reduced MICs against clinical Candida isolates (down to 0.002 µg/mL) compared with conventional echinocandins. This reduction in MIC was observed regardless of the strain's susceptibility to standard echinocandins. Enhancing the membrane activity of echinocandins through their incorporation into liposomal formulations represents a promising strategy to improve antifungal efficacy and address the increasing resistance observed in clinical Candida isolates.