Green and Facile Synthesis of Pullulan-Stabilized Silver and Gold Nanoparticles for the Inhibition of Quorum Sensing

Abstract

Pullulan (Pull) decorated with monodisperse Ag and Au nanoparticles (NPs) was synthesized by a simple and green method. Samples were characterized by FTIR, UV–vis, NMR, XRD, TGA, SEM, XPS, DLS, and TEM. SEM images showed highly oriented microforms reported for the first time for Pull, because of the supramolecular self-assembling behavior of Pull chains. Antimicrobial and quorum sensing (QS) inhibition activities were tested against six pathogen bacteria and reporter and biomonitor strain. Pull decorated with NPs, in particular, Ag-modified ones, outperformed pristine Pull. The cell proliferation was tested with an MTT assay. NPs-decorated Pull was studied for the first time as an inhibitory agent against bacterial signal molecules and found to be a good candidate. The promising performance of AgNPs@Pull compared to the commercial antibiotic gentamicin showed that it has great potential as a therapeutic approach to overcome the bacterial resistance that has developed against conventional antibiotics.

Poly(acrylic acid)-b-Poly(vinylamine) Copolymer: Decoration with Silver Nanoparticles, Antibacterial Properties, Quorum Sensing Activity, and Cytotoxicity on Breast Cancer and Fibroblast Cell Lines

“…The antibacterial inhibition zones (mm) of both samples were statistically significant ( p < 0.05). As shown in Figure a, AgNPs@PAA- b -PVAm exhibited larger inhibition zones against all the bacterial strains compared to PAA- b -PVAm, suggesting that the antibacterial activity is enhanced with the presence of Ag NPs, in agreement with previously published data. ,, The synthesized AgNPs@PAA- b -PVAm showed the highest activity against Ec (13.7 ± 0.50 mm) and Sa (12.9 ± 0.46 mm) among G– and G+ bacteria, respectively (please refer to the representative pictures in Figure S6). In addition, the antibacterial activity of copolymer structures was compared with gentamicin, a commonly used antibiotic.…”

“…The presence of metallic Ag after the incorporation of Ag NPs into the structure is evidenced by the core-level Ag 3d spectrum presented in Figure g. The Ag 3d 3/2 and Ag 3d 5/2 peaks at approximately 373.9 and 367.9 eV, respectively, prove the presence of metallic Ag NPs in the structure. , Further evidence of hydrolysis of PAA- b -PNVF copolymer was revealed by a change in zeta potential from −25.6 mV to +9.3 mV after conversion of the neutral PNVF block to basic VAm moieties (Figure h). As a result of the reduction of Ag ions, the zeta potential increases further (+15.7 mV) due to the loss of electrons, that is, oxidation of the reducing groups of the copolymer.…”

“…It has been well-documented that the development of such supramolecular arrays on surfaces is closely related to interactions such as hydrogen bonds and van der Waals interactions. , The hydrogen bonding capacity of the PVAm block formed after hydrolysis will be higher than that of PNVF. These differentiating strong interactions may have prevented the polymer chains from spreading on the mica surface and led to the formation of feather-like arrangements . It should also be noted that at a concentration of 0.1 mg/mL (same as in AFM and SEM analysis) the pH of the copolymer solution is approximately 5.1.…”

Sodium-Alginate-Functionalized Silver Nanoparticles for Colorimetric Detection of Dimethoate

“…The high-resolution spectra of Ag 3d were measured to analyze the electronic state of AgNPs in the absence and presence of dimethoate. Two peaks associated with the spin–orbit doublets at 367.7 eV (Ag 3d5/2) and 373.7 eV (Ag 3d3/2) with a spin energy separation of 6.0 eV ( Figure S1 in Supplementary Material ), which is a characteristic of zero valent metallic Ag [ 34 ]. The lower-intensity peak contribution at higher binding energy is assigned to Ag atoms at the nanoparticle surface chemically bonded to the sulfur atom of dimethoate.…”

Metal and Metal Oxide Nanomaterials for Fighting Planktonic Bacteria and Biofilms: A Review Emphasizing on Mechanistic Aspects

“…Ghaffarlou et al developed Ag NPs-decorated Pullulan (Ag NPs@Pull) and Au NPs-decorated Pullulan (Au NPs@Pull) to combat the bacterial resistance ( Figure 11 a). Ag NPs@Pull and Au NPs@Pull significantly inhibited bacterial signal molecules, according to the results [ 114 ]. Unfortunately, Ag NPs are widely known to be extremely hazardous to mammalian cells.…”