Silk Fibroin Nanoparticles with Kojic Acid

The nanoparticles were prepared based on the method described by Marinho et al., 2022 (link) with slight modifications. The nanoparticles were produced by an emulsification process, using water with 6% kojic acid and 2% silk fibroin solution. Initially, the KA and a mixture of ethanol and isopropanol (1:1) were mixed under constant magnetic agitation (300 rpm) for 5 min. The aqueous phase containing a silk fibroin solution was then slowly added, and the system was continuously agitated for 30 min using a vortex. Nanoparticles were stored at refrigerator temperature (4°C) after preparation. The droplet size, PDI and zeta potential of the nanoparticles were determined using a ZS zetasizer (Malvern, United Kingdom). Each sample was diluted with distilled water (1:10) to avoid multiple scattering effects, in accordance with Sarquis et al., 2020 (link), and all measurements were made in triplicate at 25°C. The average droplet size was expressed as mean diameter.