Rial Silva, RamónGonzález Durruthy, MichaelRuso Beiras, Juan Manuel2025-10-132025-10-132025-04Rial Silva, R., Gonzalez Durruthy, M. and Ruso Beiras, J.M. Elucidating the physicochemical interactions between fibrinogen and surfactant mixtures: Implications for pharmaceutical sciences. International Journal of Biological Macromolecules, 299, 1-13. https://doi.org/10.1016/j.ijbiomac.2025.1402650141-8130https://hdl.handle.net/10347/43061This study investigates the physicochemical interactions between fibrinogen (Fib), a key glycoprotein in blood clotting, and a mixture of two biologically active compounds: dicloxacillin (Diclox), an antibiotic; and cetyltrimethylammonium bromide (CTAB), a cationic surfactant. Understanding these interactions is crucial for enhancing drug delivery systems and optimizing pharmaceutical formulations. Molecular docking simulations and various spectroscopic techniques, including UV–Vis, fluorescence, and circular dichroism, were employed to explore how this mixture affects the structural and functional properties of fibrinogen. The docking results revealed that the binding affinity of the dicloxacillin-CTAB mixture with fibrinogen was stronger than either compound individually, suggesting a synergistic interaction. Spectroscopic analysis confirmed structural modifications in the fibrinogen molecule, notably in α-helix content and aromatic residues, indicating loosening or unfolding in protein conformation upon ligand binding. Thermodynamic analyses further supported that the binding process was driven by hydrophobic interactions and electrostatic forces, contributing to stable complex formation. This study advances the current understanding of protein-ligand interactions by exploring the synergistic effects of a dual-ligand system, a novel approach that has not been comprehensively explored in previous literature. These findings provide new insights into the design of drug delivery systems, offering potential applications for improving the efficacy and safety of pharmaceutical formulations targeting fibrinogen-related conditions.eng© 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Attribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/FibrinogenDicloxacillinCTABMolecular dockingSpectroscopic analysisProtein-ligand interactionjournal article10.1016/j.ijbiomac.2025.140265open access