Based on its outstanding antifungal properties, it is reasonable to believe that
fengycin might be efficient to topically treat localized
dermatomycoses. Since most of the fungi species involved in the formation of those mycotic
skin diseases colonize primarily the stratum corneum (SC), studying the interaction between
fengycin and SC-mimicking
lipid membranes is a primary step to determine the potential of
fengycin to overcome the physical barrier of the skin. In this respect, multilamellar
lipid vesicles (MLVs), with a
lipid composition mimicking that of the SC, were prepared and characterized by differential scanning calorimetry (DSC). The critical
micelle concentration (CMC) of
fengycin was also assessed under skin conditions and found to be 1.2±0.1μM. The molecular interactions of
fengycin with SC-mimicking MLVs were investigated by both DSC and isothermal titration calorimetry (ITC). Results showed that the interactions were considerably affected by changes in
lipid phase behaviour. At 40°C and below,
fengycin induced exothermic changes in the
lipid structures suggesting that less-ordered
lipid domains became more-ordered in presence of
fengycin. At 60°C, clearly endothermic interaction enthalpies were observed, which could arise from the "melting" of remaining solid domains enriched in high melting
lipids that without
fengycin melt at higher temperatures.