This study investigates silver (Ag), copper oxide (CuO), and bimetallic Ag/CuO nanoparticles (NPs) synthesized using Cistus creticus L. extract, focusing on their synthesis, physicochemical characteristics, and antioxidant activity. Green synthesis methods utilizing plant extracts offer environmentally benign routes for nanoparticle fabrication, attracting significant interest across multiple fields. NP formation was confirmed by UV/Vis and total X-ray fluorescence (TXRF) spectroscopy, while dynamic and electrophoretic light scattering (DLS, ELS) characterized particle size and ζ-potential, respectively. AgNPs exhibited the smallest particle size (30.8 ± 8.81 nm), while CuONPs had the largest (44.07 ± 19.19 nm). For Ag/CuONPs, the ζ-potential value was −77.9 ± 2.99 mV. Morphological and structural analyses performed using transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) revealed that AgNPs were spherical, while CuONPs and Ag/CuONPs exhibited spherical and polymorphic structures. Colloidal stability studies over 60 days demonstrated that the NPs were highly stable, indicating their suitability for pharmaceutical and cosmetic applications. Antioxidant activity, assessed via the DPPH assay, demonstrated that CuONPs had the highest free radical scavenging activity. By systemically comparing Ag, CuO, and bimetallic Ag/CuONPs synthesized from Cistus creticus L. extract, this study provides valuable insights for the development of tailored nanomaterials with diverse applications in pharmaceutics and cosmetics.

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 Tisochrysis lutea 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.

Cod liver oil is a rich source of polyunsaturated fatty acids (PUFAs) but is highly susceptible to oxidative degradation, limiting its use in topical formulations. This study aimed to develop stable cod liver oil nanoemulsions for topical application and to evaluated the influence of surfactant ratio (lecithin/PEG-15 hydroxystearate: 2.5:1 and 1:1, w/w), emulsification method (ultrasonication or high-pressure homogenization), and vitamin E acetate supplementation on their physicochemical properties and oxidative stability. Eight nanoemulsions were characterized in terms of droplet size, polydispersity, ζ-potential, vitamin E acetate encapsulation efficiency, oxidative stability, film-forming capacity and cytocompatibility. Among the investigated formulations, F4 (2.5:1 lecithin/PEG-15 hydroxystearate, high-pressure homogenization, with vitamin E acetate) exhibited the most favorable characteristics, including a mean droplet size of 67.95 nm, ζ-potential of −63.12 mV and vitamin E acetate encapsulation efficiency of 32.59%. The formulation demonstrated good physicochemical stability under thermal, mechanical and photostability testing, improved oxidative stability, transient film-forming behavior with an initial occlusive effect, and no cytotoxicity toward human dermal fibroblasts. These findings indicate that nanoemulsion performance depends on the combined influence of formulation composition and processing conditions, with F4 representing a promising topical carrier for cod liver oil intended for interaction with the stratum corneum.