Mini-emulsions based on protic ionic liquids and oleic acid for treatment of dermatophytosis caused by Microsporum canis

The decrease in the effectiveness of current treatments for hair dermatosis caused by the resistance to antifungals affects patients, causing many cases of recurrence. Thus, the search for low-cost materials with potential antifungal and antibiofilm effects that are easy to prepare, water-soluble, polydisperse and chemically green is significant. Thus, the purpose of this research is to develop mini-emulsions based on protic ionic liquids and oleic acid that present antibiofilm activity against strains related to animal hair dermatophytosis. The effects of three different protic ionic liquids (PILs), 2-hydroxy diethylammonium lactate (2-HDEALa), 2-hydroxy diethylammonium salicylate (2-HDEASa) and 2-hydroxy diethylammonium maleate (2-HDEAMa), on the size, stability and antibiofilm activity of the mini-emulsions were investigated. The effects of PILs and oleic acid concentrations on the size, polydispersity and electrostatic stability of mini-emulsions were evaluated using dynamic light scattering and electrophoretic light scattering. The raw materials and mini-emulsions were also characterized using nuclear magnetic resonance (NMR) spectroscopy and fluorescence experiments including confocal microscopy. In addition, the potential of the synthesized nanomaterials to eradicate Microsporum canis biofilms on animal hair was evaluated. As a result, it was observed that mini-emulsions with smaller sizes, a lower polydispersity index and high electrostatic stability were produced with 10 mM oleic acid and 20 mM 2-HDEALa, 50 mM 2-HDEAMa and 50 mM 2-HDEAMa using a simple and low-cost synthetic method. Furthermore, the confocal microphotographs demonstrated that the mini-emulsions had a spherical shape and the fluorescence and NMR analyses showed that the PILs 2-HDEALa and 2-HDEAMa efficiently covered the oleic acid in the mini-emulsions. Regarding the treatment of dermatophytosis in animal hair using mini-emulsions, it was found that these nanomaterials eliminated 100% of the M. canis biofilm. In conclusion, chemically green molecules such as the PILs 2-HDEALa, 2-HDEAMa and 2-HDEASa were able to form mini-emulsions easily and inexpensively with oleic acid. The PILs presented a synergetic effect with oleic acid, providing the complete eradication of the M. canis biofilm. Therefore, the results of this study suggest that these nanomaterials could be a potential water-soluble formulation to be used as a lotion in the treatment of animal hair dermatoses.