Povidone iodine (PVPI) is an antiseptic widely used against a broad spectrum of pathogens. However, undesired side-effects are still associated with PVPI treatment due to the irritant effect of iodine. Reducing the concentration of a PVPI formulation could provide safer and more friendly formulations, for routine use and applications in very delicate organs such as the eye. However, managing the storage of a low-concentration solution of PVPI is challenging due to the high iodine volatility. In this study, we demonstrated that an amphiphilic p-sulfonato-calix[4]arene derivative forming micelles (SC4OC6) improves the stability of a 0.1% PVPI aqueous buffered solution. UV-vis and NMR spectra as well as dynamic and electrophoretic light scattering measurements showed that SC4OC6 establishes non-covalent supramolecular interactions with PVPI, resulting in the formation of nanoaggregates with a negatively charged surface. Isothermal titration calorimetry provided the aggregation parameters and evidenced that the formation of the supramolecular assembly is an enthalpically favored process. The interaction of SC4OC6 with PVPI enhances the iodine retention and stability of the solution without affecting the rapid and effective bactericidal activity of PVPI, as demonstrated by a time-killing assay with Staphylococcus epidermidis.

Resveratrol is one of the most extensively studied natural products due to its pleiotropic health benefits. However, its low water solubility and limited stability hinder its application in the nutraceutical, cosmetic, and pharmaceutical sectors. In this work, we investigated the ability of a cationic mono-choline-β-cyclodextrin derivative to complex trans-resveratrol. The complex was prepared using a phase solubility method without using organic solvents and was found to be stable after freeze-drying. The complex was characterized by a phase solubility study, NMR spectroscopy, and molecular modeling simulations, which revealed a 1:1 stoichiometry, a stability constant of 2051 M⁻¹ (K_C), and structural details. Complexation improved resveratrol’s solubility and dissolution rate, reduced its photoinduced trans-to-cis isomerization, and preserved its radical scavenging activity. The wound-healing activity of the complex was demonstrated via in vitro experiments on human keratinocyte cells.

Background: In melanoma, multiligand drug strategies to disrupt cancer-associated epigenetic alterations and angiogenesis are particularly promising. Here, a novel dual-ligand with a single shared pharmacophore capable of simultaneously targeting histone deacetylases (HDACs) and sigma receptors (σRs) was synthesized and subjected to phenotypic in vitro screening. Methods: Tumor cell proliferation and spreading were investigated using immortalized human cancer and normal cell lines. Angiogenesis was also evaluated in mouse endothelial cells using a tube formation assay. Results: The dual-ligand compound exhibited superior potency in suppressing both uveal and cutaneous melanoma cell viability compared to other cancer cell types or normal cells. Melanoma selectivity reflected inhibition of the HDAC-dependent epigenetic regulation of tumor proliferative kinetics, without involvement of σR signaling. In contrast, the bifunctional compound inhibited the formation of capillary-like structures, formed by endothelial cells, and tumor cell spreading through the specific regulation of σ₁R signaling, but not HDAC activity. Conclusions: Together, the present findings suggest that dual-targeted HDAC/σ₁R ligands might efficiently and simultaneously disrupt tumor growth, dissemination and angiogenesis in melanoma, a strategy amenable to future clinical applications in precision cancer treatment.