Brewer’s spent grain-derived ferulic acid loaded into ultradeformable liposomes for topical application: validation in 2D/3D skin models

Brewer’s spent grains (BSG), a major by-product of the brewing industry, represent an abundant and sustainable resource for bioactive compounds like ferulic acid (FA), a potent natural antioxidant. This study utilized chemical, enzymatic, and hydrothermal hydrolysis methods to extract FA, achieving the highest encapsulation efficiencies (97-98%) through enzymatic and hydrothermal processes. By incorporating FA into advanced nano-delivery systems, the research demonstrated enhanced stability, bioavailability, and regenerative properties in in vitro models, including HaCaT and human dermal fibroblast (HDF) cells, as well as 3D reconstructed epidermis. These systems promoted wound closure (50% in 6 hours and 100% in 24 hours) and reduced reactive oxygen species levels by 94%, highlighting their efficacy. This work showcases a circular economy approach, transforming BSG from waste into a valuable resource, paving the way for sustainable applications in cosmetics and pharmaceuticals. • Hydrothermal treatment of BSG enhanced ferulic acid extraction for nano-encapsulation • Ultradeformable liposomes (ULs) enhanced FA stability, bioavailability, and effects. • FA-loaded ULs achieved >90% encapsulation and extended stability to 188 days. • FA-loaded ULs promoted 50% wound healing in HaCaT and HDF cells within 6 hours. • ULs with FA reduced ROS levels by 94%, surpassing free FA in skin protection