Formulation of MFS-Alginate Nanoparticles

A formulation of MFS encapsulated in alginate nanoparticles (MFS-AN) was prepared by emulsification using the external gelation method, as previously described (Ishida et al., 2017 ; Spadari et al., 2019 (link)). Briefly, 3 mg MFS were dissolved in 1% (w/v) sodium alginate aqueous solution and mixed with 3% (w/v) sorbitan monooleate (SPAN 80) in sunflower oil to form an emulsion. Induction of nanoparticle formation was triggered by dripping 0.2 M CaCl₂ with 0.5% polaxamer into the emulsion, under constant stirring. Then, the formulation was centrifuged and resuspended in 10% trehalose before freeze-drying, to obtain a fine powder (Ishida et al., 2017 ; Spadari et al., 2019 (link)). The mean size (Dz), polidispersion (Pdi), and zeta potential (ζ) of nanoparticles were measured in a Zetasizer NanoZS90 particle analyzer (Malvern Instruments, Worcestershire, United Kingdom). The lyophilized powder showed physical-chemical stability and in vitro antifungal activity for up to 30 days (Ishida et al., 2017 ; Spadari et al., 2019 (link)). For the in vivo assay MFS-AN (2% MFS) was incorporated in 1% (w/v) alginate gel.