Bioinspired RGD-Functionalized Gold Nanoparticles for Integrin-Driven Interaction with Melanoma Cells

Annarita Del Gatto,1,2,* Patrizia Di Pietro,3,* Michele Saviano,2,4 Marianna Flora Tomasello,4 Giuseppe Pappalardo,4 Rony Snyders,5,6 Giuseppe Forte,7 Cristina Satriano,3 Laura Zaccaro1,2 1Institute of Biostructures and Bioimaging (IBB), Naples, Italy; 2Interuniversity Research Centre on Bioactive Peptides (CIRPeB) “carlo Pedone”, University of Naples, Naples, Italy; 3NanoHybrid Biointerfaces Laboratory (NHBIL), Department of Chemical Sciences, University of Catania, Catania, Italy; 4Institute of Crystallography (IC), Bari, Italy; 5Plasma-Surface Interaction Chemistry, University of Mons, Mons, Belgium; 6Materia Nova Research Center, Mons, Belgium; 7Department of Drug and Health Sciences, University of Catania, Catania, Italy*These authors contributed equally to this workCorrespondence: Cristina Satriano, Department of Chemical Sciences, University of Catania, Viale Andrea Doria, 6, Catania, 95125, Italy, Tel +39 0957385136, Email [email protected]: In this study, we investigated the physicochemical properties, biofunctionalization and internalization mechanisms of peptide-functionalized gold nanoparticles (GNPs), with a particular focus on a cyclic avβ3 integrin-targeting ligand (cRGD), embedded in a scaffold comprising a gold-binding glycine-cysteine tetrapeptide (GCt) and a fluorescein isothiocyanate (FITC) dye.Methods: The characterisation of the GNPs and their biofunctionalised counterparts (b-GNPs) was carried out by a series of techniques including dynamic light scattering (DLS), zeta potential (ζ) measurements, UV-visible (UV-vis) spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and theoretical modelling. Cellular uptake experiments were performed in human adenocarcinoma (HeLa, avβ3 non-expressing cells, negative control) and metastatic melanoma (WM266, avβ3-overexpressing cells, positive control) cells to assess receptor-mediated internalization.Results: The physicochemical characterisation confirmed the successful functionalisation of GNPs with the bioinspired multifunctional cRGD-GCt-FITC moiety. Detailed analysis of the nano-bio interface revealed distinct chemical states and evidence of charge transfer effects between the GNPs surface and the RGD-containing peptide. Cellular studies demonstrated selective uptake and preferential accumulation of b-GNPs in avβ3-overexpressing cells, with RGD-functionalised GNPs inducing notable pro-apoptotic effects.Conclusion: This work provides new understanding of biomimetic gold nanoparticles and highlights their potential in tumour selective strategies, particularly for integring-targeted theranostics, while addressing toxicity and targeting limitations of current RGD- and gold nanoparticle-based nanomedicine.Keywords: plasmonic nanoparticles, theranostics, targeting, cancer nanomedicine, peptide