Topical Delivery of Artificial Lipidated Antifungal Proteins for the Treatment of Subcutaneous Fungal Infections Using a Biocompatible Ionic Liquid-Based Microemulsion

The rising incidence of fungal infections, compounded by the emergence of severe antifungal resistance, has resulted in an urgent need for innovative antifungal therapies. We developed an antifungal protein-based formulation as a topical antifungal agent by combining an artificial lipidated chitin-binding domain of antifungal chitinase (LysM-lipid) with recently developed ionic liquid-in-oil microemulsion formulations (MEFs). Our findings demonstrated that the lipid moieties attached to LysM and the MEFs effectively disrupted the integrity of the stratum corneum in a mouse skin model, thereby enhancing the skin permeability of the LysM-lipids. Among the MEFs incorporating LysM modified with lauric (C12), myristic (C14), and palmitic (C16) acids, the LysM-C14-loaded MEF emerged as the most promising candidate, exhibiting potent antifungal activity against Trichoderma viride growing actively beneath the skin. The stability of the MEFs was investigated after a 28 day storage period at room temperature, and both LysM-C14- and LysM-C16-loaded MEFs retained comparable antifungal activity with that of the freshly prepared MEFs. These results highlight the considerable potential of LysM-lipid-loaded MEFs as effective topical antifungal agents.