A bioinspired approach to scrutinize the interaction between cancer cells and noble metal nanoparticle-based biomaterials

Gold (Au), silver (Ag), and palladium (Pd) nanoparticles (NPs), with intrinsic antiangiogenic, antibacterial, and anti-inflammatory properties, have great potential as potent chemotherapeutics, due to their unique features, including plasmonic properties for application in photothermal therapy, and their capability to slow down the migration/invasion speed of cancer cells and then suppress metastasis. In this work, AuNP, AgNP, and PdNP were synthesized by a green redox chemistry method by the glucose-driven reduction of the metal salt precursor in the presence of polyvinylpyrrolidone (PVP) as stabilizing and capping agent. The physicochemical properties of the PVP-capped NPs were investigated by UV-visible (UV-vis) spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM), to estimate the optical diameter, the hydrodynamic size, and the morphology, respectively. Biophysical studies with model cell membranes were carried out by using laser scanning confocal microscopy (LSM) with Fluorescence recovery After Photobleaching (FRAP) and Fluorescence Resonance Energy Transfer (FRET) techniques. To this purpose, artificial cell membranes of supported lipid bilayers (SLBs) made with 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphocholine (POPC) dye-labeled with 7-nitro-2-1,3-benzoxadiazol-4-yl (NBD, FRET donor) and/or lissamine rhodamine B sulfonyl (Rh, FRET acceptor) were prepared. In vitro cellular experiments were carried out with prostate cancer cells (PC-3 line) in terms of the cell viability, the cell migration process (wound scratch assay), NP cellular uptake, and cytoskeleton actin perturbation.