Encapsulation of Microalgae Extract in Nanostructured Lipid Carriers (NLCs) and Evaluation of Their Sunscreen, Wound Healing, and Skin Hydration Properties.

Traditional sunscreens have relied on synthetic compounds to protect against harmful ultraviolet (UV) radiation. However, there is increasing interest in utilizing the natural photoprotective properties of microalgae extracts. This approach does not only aim to enhance the stability and efficacy of sun protection formulae but also seeks to reduce the reliance on synthetic sunscreens. This study investigates the encapsulation of extract (TL) in nanostructured lipid carriers (NLCs) to create a combination (NLC-TL) with enhanced physicochemical stability, antioxidant activity, SPF efficacy, wound healing capacity, and skin hydration. The particle size and ζ-potential were approximately 100 nm and -50 mV, respectively, and both formulations successfully passed the stability tests. The antioxidant activity, measured via DPPH assay, revealed that NLC-TL achieved the highest free radical scavenging activity across all tested concentrations, indicating a synergistic effect. The incorporation of TL in NLCs maintained the sun protection factor (SPF) of a 2% extract solution (1.53 ± 0.13). The wound healing assay indicated that NLC-TLs significantly enhanced wound closure compared to controls and TL alone. Additionally, skin hydration tests on healthy volunteers revealed that NLC-TLs provided superior and sustained hydration effects. These results highlight NLC-TLs' potential as a multifunctional topical agent for cosmetic and therapeutic applications.