The Density of Surface Coating Can Contribute to Different Antibacterial Activities of Gold Nanoparticles

Abstract

With the widespread use of antibiotics, the number of complex infection cases caused by unknown pathogens is increasing and novel antibiotics with tunable antibacterial spectra and low toxicity are highly desirable. Herein, we report that, by selecting thiol or amine, two groups with different binding affinities with gold, as anchoring groups, phenylboronic acid can be decorated on gold nanoparticles (AuNPs) with different densities, which contributes to Gram-selective antibacterial activities of the AuNPs. The AuNPs modified with amine- or thiol-tethered phenylboronic acids specifically bind to lipopolysaccharide (LPS, Gram-negative) or lipoteichoic acid (LTA, Gram-positive), respectively. By modifying AuNPs with different ratios of thiol- and amine-tethered phenylboronic acids, the resulting AuNPs show potent and tunable antibacterial activity. The AuNP-based antibacterial agents with optional Gram selectivity are promising for applications in personalized therapy.

Novel Strategy to Combat Antibiotic Resistance: A Sight into the Combination of CRISPR/Cas9 and Nanoparticles

“…For instance, silver nanoparticles (AgNPs) have been widely used as potent antimicrobials against bacteria because of their remarkable bactericidal effect exceeding that of other metal oxides and reduced possibility of inducing resistance. Gold nanoparticles (AuNPs) are another type of inorganic nanoparticles that widely tested as antimicrobial agent because of their photothermal activity, biocompatibility, and easy modification with small antimicrobial drugs [65,[66][67][68]. Furthermore, there is a particular interest in biosynthesized nanoparticles, such as copper nanoparticles prepared with Zingiber officinale, and Curcuma longa that displayed a remarkable antibacterial activity against multidrug resistant Staphylococcus aeureus [68].…”

A New Class of Multi-Armed Antibiotics with Low Risk of Resistance

“…We also compare the inhibition effects of MAAs and ampicillin, Oxacillin and vancomycin by testing the optical density at 600 nm (OD600) of bacterial suspensions by microplate readers (Tecan infinite M200), and recording the turbidities of bacterial suspensions by Nikon D90 camera. 36 Time-dependent killing assay. We incubate MRSA (≈10 6 CFU/mL) with different concentration of MAAs (0.5, 1 and 2 g/mL), oxacillin (32 μg/mL) and vancomycin (32 μg/mL) in LB medium for 4, 8, 12, and 24 h. 23,37,38 The suspensions are diluted for 10, 1000, and 100000 folds, and 100 L of the dilutions are placed on LB plates and incubated at 37  C for 24 h. Colonies are counted and CFU/ml is calculated.…”

Antibacterial Properties of Functionalized Gold Nanoparticles and Their Application in Oral Biology

“…Wang et al reported that two groups with different binding affinity to gold were used as anchor groups, and thiols or amines were used to modify phenylboronic acid on gold nanoparticles (AuNPs) with different densities. Different bacteria will have selective antibacterial properties, which are expected to be used for personalized treatment [67]. Gold nanoclusters conjugated with various surface ligands have high biocompatibility, multivalent effects, easy modification, and photothermal stability, so they are potential antibacterial agents.…”