Metal-based nanoparticles in antibacterial application in biomedical field: Current development and potential mechanisms

Abstract

The rise in drug resistance in pathogenic bacteria greatly endangers public health in the post-antibiotic era, and drug-resistant bacteria currently pose a great challenge not only to the community but also to clinical procedures, including surgery, stent implantation, organ transplantation, and other medical procedures involving any open wound and compromised human immunity. Biofilm-associated drug failure, as well as rapid resistance to last-resort antibiotics, necessitates the search for novel treatments against bacterial infection. In recent years, the flourishing development of nanotechnology has provided new insights for exploiting promising alternative therapeutics for drug-resistant bacteria. Metallic agents have been applied in antibacterial usage for several centuries, and the functional modification of metal-based biomaterials using nanotechnology has now attracted great interest in the antibacterial field, not only for their intrinsic antibacterial nature but also for their ready on-demand functionalization and enhanced interaction with bacteria, rendering them with good potential in further translation. However, the possible toxicity of MNPs to the host cells and tissue still hinders its application, and current knowledge on their interaction with cellular pathways is not enough. This review will focus on recent advances in developing metallic nanoparticles (MNPs), including silver, gold, copper, and other metallic nanoparticles, for antibacterial applications, and their potential mechanisms of interaction with pathogenic bacteria as well as hosts.

Keywords: Anti-bacterial therapy; Biomaterials; Drug resistance; Metallic nanoparticles; Nanotechnology.

Fig. 1

Investigation of the molecular mechanisms of AgNP cytotoxicity by using antioxidants, showing the molecular interaction between the thiol-antioxidants and non-thiol-antioxidants with chemically and biologically synthesized AgNP. Both antioxidants could mitigate ROS production in Huh-7 hepatocarcinoma cells. Nanomedicine. 2020 Feb;24:102130

Fig. 2

In vitro antimicrobial activity of the hybrid nanocoatings against MRSA and P. aeruginosa. A, B: CFU of MRSA (A) or P. aeruginosa (B) biofilms; C, D: representative LIVE/DEAD stain CLSM images of MRSA (C) or P. aeruginosa (D) biofilms. All biofilms were grown on the tested surfaces after 6 h incubation in quasi-static conditions with different treatments, * p-value < 0.05; ** p-value < 0.01; *** p-value < 0.001; **** p-value < 0.0001. Three biological replicates with three samples in each experiment for each group were performed for each bacteria strain (N = 9). All scale bars are 100 μm. Acta Biomater. 2022 Mar 1;140:338–349

Fig. 3

Animal studies of renal clearable gold nanoparticles from the Zheng group in the past decade are integrated with the latest FDA guidance on nanomedicines. Angew Chem Int Ed Engl. 2019 Mar 22;58 (Yougbare et al. 2021):4112–4128

Fig. 4

The double staining(SYTO9 and PI) assay for membrane damage of E. coli, K. pneumoniae, P. aeruginosa, S. typhi, S. marcescens, and P. mirabilis treated by ZnO NPs. Live bacteria with intact membranes appear green, and the injured/damaged bacterial cells appear yellow/red. The bar diagram represents the fluorescent mean intensity. Copyright (2022) authors. Licensee MDPI, Basel, Switzerland, Molecules 2022, 27 (Souza et al. 2019), 2489

Fig. 5

The proposed antibacterial mechanisms of vancomycin-coated AgNPs. Copyright © 2022 Mohsina Patwekar et al., Biomed Res Int. 2022 Aug 21;2022:3682757