The interest in the use of copper as a metal scaffold for the development of novel chemotherapeutics has considerably grown in recent years. This is mainly due to the relatively lower toxicity of copper complexes with respect to platinum drugs (i.e., cisplatin), the different mechanisms of action, and the cheaper cost. In the last decades, hundreds of copper-based complexes were developed and screened as anticancer agents, with the antesignanus of all compounds being copper bis-phenanthroline [Cu(phen)₂]²⁺ developed by D.S. Sigman in the late 1990s. In particular, copper(phen) derivatives have been shown high interest in their capacity to interact with DNA by nucleobase intercalation. Here, we report the synthesis and chemical characterization of four novel copper(II) complexes functionalised with phenanthroline derivatives containing biotin. Biotin, also known as Vitamin B7, is involved in a series of metabolic processes, and its receptors are often overexpressed in many tumour cells. A detailed biological analysis including cytotoxicity in 2D and 3D, cellular drug uptake, DNA interaction, and morphological studies are discussed.

Arthrospira platensis (commonly known as Spirulina platensis) is a blue-green microalga increasingly used in skincare due to its antioxidant and dermo-protective properties, primarily attributed to components such as phycocyanin and carotenoids. However, the intense blue color of phycocyanin can limit its cosmetic appeal. In this study, we investigated the antioxidant, anti-inflammatory, skin lightening and photoprotective activity of Elixspir^®, a novel light-colored aqueous extract of Spirulina, using both 2D and 3D skin cell models. We demonstrated that Elixspir^® exerts strong antioxidant and cytoprotective effects by reducing intracellular ROS levels and modulating cellular thiol redox state. Its anti-pigmentation potential was supported by tyrosinase inhibition, while anti-inflammatory activity was principally due to ability to reduce PGE2 levels. Finally, we demonstrated an unprecedented photoprotective effect of Elixspir^®, highlighting its potential as a novel active ingredient for skin defense against environmental stressors. Overall, these results provide a molecular-level understanding of Elixspir^® multifunctional bioactivity and support its application as a skin-lightening, anti-inflammatory, antioxidant, and photoprotective ingredient in the formulation of innovative skin anti-aging treatments.