Photoprotective and Antioxidant Liposomal Formulations from <i>Sargassum</i> -Derived Biomolecules for Skincare Applications

The development of sustainable skincare formulations is increasingly important due to growing customer demand for eco-friendly and health-conscious products. Conventional formulations often rely on synthetic ingredients that can harm human health and marine ecosystems, underscoring the need for natural and biodegradable alternatives. Recurrent <i>Sargassum</i> blooms in tropical regions generate vast, underutilized biomass, posing environmental and economic challenges, such as habitat disruption and waste accumulation. Valorizing this biomass for nanocarrier production aligns with circular economic principles and promotes marine resource utilization. This study developed and characterized fucoidan-coated liposomes as nanocarriers for skincare applications through comprehensive physicochemical and functional evaluations. Lipids extracted from <i>Sargassum</i> were combined with fucoidan, a sulfated polysaccharide, using the thin-film hydration technique in a 1:1 v/v ratio. Treatments included empty and fucoidan-coated liposomes, assessed for particle size, zeta potential, thermal stability, photodegradation resilience, and antioxidant activity. Fucoidan-coated liposomes exhibited a particle size of 673 ± 10 nm, a PDI of 0.8, and a zeta potential of -72 mV, maintaining colloidal stability for 28 days. FTIR confirmed structural integrity under simulated sunlight, while TGA, DSC, and gas chromatography showed improved lipid retention and thermal stability. Although empty liposomes exhibited stronger initial radical scavenging activity (0.9 ± 0.4 g/L), fucoidan-coated liposomes (2.0 ± 0.6 g/L) provided more sustained antioxidant effects due to the protective polysaccharide layer. This approach integrates marine biomass valorization with enhanced liposomal stability and antioxidant performance, positioning fucoidan-coated <i>Sargassum</i> liposomes as a robust and eco-friendly platform for next-generation skincare formulations within a circular economy framework.