Composition-Dependent Cytotoxic and Antibacterial Activity of Biopolymer-Capped Ag/Au Bimetallic Nanoparticles against Melanoma and Multidrug-Resistant Pathogens

Abstract

Nanostructured silver (Ag) and gold (Au) are widely known to be potent biocidal and cytotoxic agents as well as biocompatible nanomaterials. It has been recently reported that combining both metals in a specific chemical composition causes a significant enhancement in their antibacterial activity against antibiotic-resistant bacterial strains, as well as in their anticancer effects, while preserving cytocompatibility properties. In this work, Ag/Au bimetallic nanoparticles over a complete atomic chemical composition range were prepared at 10 at% through a green, highly reproducible, and simple approach using starch as a unique reducing and capping agent. The noble metal nanosystems were thoroughly characterized by different analytical techniques, including UV-visible and FT-IR spectroscopies, XRD, TEM/EDS, XPS and ICP-MS. Moreover, absorption spectra simulations for representative colloidal Ag/Au-NP samples were conducted using FDTD modelling. The antibacterial properties of the bimetallic nanoparticles were determined against multidrug-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus, showing a clear dose-dependent inhibition even at the lowest concentration tested (5 µg/mL). Cytocompatibility assays showed a medium range of toxicity at low and intermediate concentrations (5 and 10 µg/mL), while triggering an anticancer behavior, even at the lowest concentration tested, in a process involving reactive oxygen species production per the nanoparticle Au:Ag ratio. In this manner, this study provides promising evidence that the presently fabricated Ag/Au-NPs should be further studied for a wide range of antibacterial and anticancer applications.

Green biosynthesis of bimetallic selenium–gold nanoparticles using Pluchea indica leaves and their biological applications

“… Lomelí-Marroquín et al (2019) reported that bimetallic Ag–Au NPs showed anticancer activity against human melanoma cells. Similarly, Nieto-Argüello et al (2022) confirmed that the use of bimetallic Ag–Au nanoparticles exhibits an anticancer impact on melanoma cells. This effect may be related to excessive ROS generated within the surrounding medium.…”

Unveiling anticancer, antimicrobial, and antioxidant activities of novel synthesized bimetallic boron oxide–zinc oxide nanoparticles

“…Previous studies reported that bimetallic nanoparticles have promising cytotoxic activities against cancerous cell lines. 80–85 Moreover, both cancerous MCF-7 and Caco 2 cell lines were used to evaluate bimetallic Ag–ZnO NPs, where bimetallic Ag–ZnO had promising anticancer activity, and IC 50 were 104.9 and 52.4 μg ml −1 , respectively. 81…”

“…Previous studies reported that bimetallic nanoparticles have promising cytotoxic activities against cancerous cell lines. [80][81][82][83][84][85] Moreover, both cancerous MCF-7 and Caco 2 cell lines were used to evaluate bimetallic Ag-ZnO NPs, where bimetallic Ag-ZnO had promising anticancer activity, and IC 50 were 104.9 and 52.4 mg ml −1 , respectively. 81 Additionally, bimetallic ZnO-Ag NPs were fabricated using laser ablation and results conrmed that bimetallic ZnO-Ag NPs have anticancer activity against the malignant cell lines HCT 116 and HeLa.…”

Metal nanoparticle hybrid hydrogels: the state-of-the-art of combining hard and soft materials to promote wound healing

“…Research has employed biopolymer starch as a reducing and capping agent for the environmentally friendly, repeatable, and simple synthesis of Ag/Au bimetallic nanoparticles. These nanoparticles demonstrated excellent antimicrobial performance against multidrug-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus, promoting wound healing and reducing scar formation [142]. Furthermore, Imran et al utilized zinc oxide (ZnO) coverage on biogenic gold nanoparticles obtained from Hibiscus plant extracts to synthesize Au@ZnO core-shell nanocomposites [140].…”