Browse
Submit Data
Databases
API
Help

Dataset Information

7 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The interaction of Ag₂O nanoparticles with Escherichia coli: inhibition-sterilization process.

ABSTRACT: Silver-based antibacterial agents have obtained wide attention due to the fact that bacteria in the environment is ubiquitous, which has become one of the most difficult problems for human health. However, the antibacterial mechanism and process are still inconclusive. Here, Ag₂O nanoparticles (NPs) with uniform spherical morphology and small size (around 30 nm) were prepared. The as-prepared Ag₂O NPs induced high antibacterial activity (100% inhibition ratio) against E. coli. A two-step antibacterial process was proposed and confirmed, which divided into inhibition and sterilization steps. The optical density measurement, malondialdehyde concentration detection, morphologic imaging with electronic microscopy and Fourier transform infrared spectroscopic analysis unveiled the interaction of Ag₂O NPs with E. coli, which verified the inhibition-sterilization process we proposed.

SUBMITTER: Li D

PROVIDER: S-EPMC7813836 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

The interaction of Ag2O nanoparticles with Escherichia coli: inhibition-sterilization process.

Li Danqing D Chen Shuai S Zhang Ke K Gao Nan N Zhang Miao M Albasher Gadah G Shi Jiangfan J Wang Chuanyi C

Scientific reports 20210118 1

Silver-based antibacterial agents have obtained wide attention due to the fact that bacteria in the environment is ubiquitous, which has become one of the most difficult problems for human health. However, the antibacterial mechanism and process are still inconclusive. Here, Ag2O nanoparticles (NPs) with uniform spherical morphology and small size (around 30 nm) were prepared. The as-prepared Ag2O NPs induced high antibacterial activity (100% inhibition ratio) against E. co ...[more]

PMID: 33462370

Similar Datasets

Targeted and Enhanced Antimicrobial Inhibition of Mesoporous ZnO-Ag2O/Ag, ZnO-CuO, and ZnO-SnO2 Composite Nanoparticles.

Project description:In this work, mesoporous (pore size below 4 nm) composite nanoparticles of ZnO-Ag2O/Ag, ZnO-CuO, and ZnO-SnO2 of size d ≤ 10 nm (dia.) have been synthesized through the in situ solvochemical reduction method using NaBH4. These composite nanoparticles exhibited excellent killing efficacy against Gram-positive/negative bacterial and fungal strains even at a very low dose of 0.010 μg/mL. Additionally, by applying the in silico docking approach, the nanoparticles and microorganism-specific targeted proteins and their interactions have been identified to explain the best anti-bacterial/anti-fungal activities of these composites. For this purpose, the virulence and resistance causing target proteins such as PqsR, RstA, FosA, and Hsp90 of Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Candida albicans have been identified to find out the best inhibitory action mechanisms involved. From the in vitro study, it is revealed that all the composite nanoparticle types used here can act as potent antimicrobial components. All the composite nanoparticles have exhibited excellent inhibition against the microorganisms compared to their constituent single metal or metal oxide nanoparticles. Among the nanoparticle types, the ZnO-Ag2O/Ag composite nanoparticles exhibited the best inhibition activity compared to the other reported nanoparticles. The microorganisms which are associated with severe infections lead to the multidrug resistance and have become a huge concern in the healthcare sector. Conventional organic antibiotics are less stable at a higher temperature. Therefore, based on the current demands, this work has been focused on designing inorganic antibiotics which possess stability even under harsh conditions. In this direction, our developed composite nanoparticles were explored for potential uses in the healthcare technology, and they may solve many problems in global emergency and epidemics caused by the microorganisms.

| S-EPMC8637601 | biostudies-literature

A macrocycle-assisted nanoparticlization process for bulk Ag2S.

Project description:We report herein a new nanoparticlization process for the bulk-to-nano transformation of Ag2S by incorporating both top-down and bottom-up approaches. Bulk Ag2S was dissolved in solution with the assistance of a macrocyclic ligand, hexamethylazacalix[6]pyridine (Py[6]), to produce polynuclear silver sulfide cluster aggregates. All Ag-S cluster aggregates obtained in three crystalline complexes were protected by Py[6] macrocycles. Removing the protective Py[6] macrocycles by protonation led to the generation of unconventional Ag-S nanoparticles with a large energy gap. Theoretical calculations by a hybrid DFT method demonstrated that the silver sulfide clusters with high Ag/S ratio exhibited more localized HOMO-LUMO orbitals, which consequently enlarged their band gap energies. These experimental and theoretical studies broaden our understanding of the fabrication of nanomaterials by virtue of the advantages of both bottom-up and top-down methods and meanwhile provide a viable means of adjusting the band gap of binary nanomaterials independent of their size.

| S-EPMC5491957 | biostudies-literature

Synthesis of M-Ag3PO4, (M = Se, Ag, Ta) Nanoparticles and Their Antibacterial and Cytotoxicity Study.

Project description:Silver Phosphate, Ag3PO4, being a highly capable clinical molecule, an ultrasonic method was employed to synthesize the M-Ag3PO4, (M = Se, Ag, Ta) nanoparticles which were evaluated for antibacterial and cytotoxicity activities post-characterization. Escherichia coli and Staphylococcus aureus were used for antibacterial testing and the effects of sonication on bacterial growth with sub-MIC values of M-Ag3PO4 nanoparticles were examined. The effect of M-Ag3PO4 nanoparticles on human colorectal carcinoma cells (HCT-116) and human cervical carcinoma cells (HeLa cells) was examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay and DAPI (4',6-diamidino-2-phenylindole) staining. Additionally, we analyzed the effect of nanoparticles on normal and non-cancerous human embryonic kidney cells (HEK-293). Ag-Ag3PO4 exhibited enhanced antibacterial activity followed by Ta-Ag3PO4, Ag3PO4, and Se-Ag3PO4 nanoparticles against E. coli. Whereas the order of antibacterial activity against Staphylococcus aureus was Ag3PO4 > Ag-Ag3PO4 > Ta-Ag3PO4 > Se-Ag3PO4, respectively. Percentage inhibition of E. coli was 98.27, 74.38, 100, and 94.2%, while percentage inhibition of S. aureus was 25.53, 80.28, 99.36, and 20.22% after treatment with Ag3PO4, Se-Ag3PO4, Ag-Ag3PO4, and Ta-Ag3PO4, respectively. The MTT assay shows a significant decline in the cell viability after treating with M-Ag3PO4 nanoparticles. The IC50 values for Ag3PO4, Se-Ag3PO4, Ag-Ag3PO4, and Ta-Ag3PO4 on HCT-116 were 39.44, 28.33, 60.24, 58.34 µg/mL; whereas for HeLa cells, they were 65.25, 61.27, 75.52, 72.82 µg/mL, respectively. M-Ag3PO4 nanoparticles did not inhibit HEK-293 cells. Apoptotic assay revealed that the numbers of DAPI stained cells were significantly lower in the M-Ag3PO4-treated cells versus control.

| S-EPMC9569642 | biostudies-literature

Efficient cyanide sensing using plasmonic Ag/Fe3O4 nanoparticles.

Project description:In the line of our previous studies, we have reported a developed sensitive and selective probe for cyanide detection based on Ag/Fe3O4 nanoparticles (NPs) with an extremely low limit of detection at the level of ng per milliliter. Herein, we report the improvement of the easy-to-make magnetic silver nanoparticle-based sensor system for cyanide determination in an extended calibration range with higher selectivity and precision. As far as our knowledge is concerned, the detectable linear range from 1.0 nM to 160 μM (0.026 ng mL-1 to 4.16 μg mL-1) of the improved simple highly precise technique represents the widest assay that has been reported so far. The method is based on strong enhancement of scattered light of the plasmonic nanoparticles and simultaneously cyanide fluorescence quenching. Although the fluorescence of cyanide is highly selective and precise, its intensity is poor. On the other hand, the strongly enhanced Rayleigh signal has a low repeatability. We proposed a method to remove the interference and obtained an effective factor that is directly proportional to cyanide concentration utilizing both above signals simultaneously. In this work, Ag/Fe3O4 NPs have been synthesized easily using a green preparation method and the NPs were consequently characterized using powder XRD, UV-Vis absorption spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). A combination of absorption, Rayleigh and fluorescence characteristics were used for detection of cyanide in real samples and an overview of recently reported sensors for cyanide was also provided.

| S-EPMC10633889 | biostudies-literature

Enhanced Inhibition of Drug-Resistant Escherichia coli by Tetracycline Hydrochloride-Loaded Multipore Mesoporous Silica Nanoparticles.

Project description:Drug-resistant bacterial infections exhibit a major threat to public health. Thus, exploring a novel antibacterial with efficient inhibition is urgently needed. Herein, this paper describes three types of MSNs (MSNs-FC2-R1, MSNs-FC2-R0.75, MSNs-FC2-R0.5) with controllable pore size (4-6 nm) and particle size (30-90 nm) that were successfully prepared. The MSNs were loaded with tetracycline hydrochloride (TCH) for effective inhibition of Escherichia coli (ATCC25922) and TCH-resistant Escherichia coli (MQ776). Results showed that the loading capacity of TCH in three types of MSNs was as high as over 500 mg/g, and the cumulative release was less than 33% in 60 h. The inhibitory rate of MSNs-FC2-R0.5 loaded with TCH against E. coli and drug-resistant E. coli reached 99.9% and 92.9% at the concentration of MIC, respectively, compared with the other two types of MSNs or free TCH. Modified MSNs in our study showed a great application for long-term bacterial growth inhibition.

| S-EPMC8877189 | biostudies-literature

Antibacterial and Osteogenic Properties of Ag Nanoparticles and Ag/TiO2 Nanostructures Prepared by Atomic Layer Deposition.

Project description:The combination of titania nanofilms and silver nanoparticles (NPs) is a very promising material, with antibacterial and osseointegration-induced properties for titanium implant coatings. In this work, we successfully prepared TiO2 nanolayer/Ag NP structures on titanium disks using atomic layer deposition (ALD). The samples were studied by scanning electron microscopy (SEM), X-ray diffraction, X-ray photoelectron spectroscopy (XPS), contact angle measurements, and SEM-EDS. Antibacterial activity was tested against Staphylococcus aureus. The in vitro cytological response of MG-63 osteosarcoma and human fetal mesenchymal stem cells (FetMSCs) was examined using SEM study of their morphology, MTT test of viability and differentiation using alkaline phosphatase and osteopontin with and without medium-induced differentiation in the osteogenic direction. The samples with TiO2 nanolayers, Ag NPs, and a TiO2/Ag combination showed high antibacterial activity, differentiation in the osteogenic direction, and non-cytotoxicity. The medium for differentiation significantly improved osteogenic differentiation, but the ALD coatings also stimulated differentiation in the absence of the medium. The TiO2/Ag samples showed the best antibacterial ability and differentiation in the osteogenic direction, indicating the success of the combining of TiO2 and Ag to produce a multifunctional biocompatible and bactericidal material.

| S-EPMC9149969 | biostudies-literature

Inhibition of Protein Secretion in Escherichia coli and Sub-MIC Effects of Arylomycin Antibiotics.

Project description:At sufficient concentrations, antibiotics effectively eradicate many bacterial infections. However, during therapy, bacteria are unavoidably exposed to lower antibiotic concentrations, and sub-MIC exposure can result in a wide variety of other effects, including the induction of virulence, which can complicate therapy, or horizontal gene transfer (HGT), which can accelerate the spread of resistance genes. Bacterial type I signal peptidase (SPase) is an essential protein that acts at the final step of the general secretory pathway. This pathway is required for the secretion of many proteins, including many required for virulence, and the arylomycins are a class of natural product antibiotics that target SPase. Here, we investigated the consequences of exposing Escherichia coli cultures to sub-MIC levels of an arylomycin. Using multidimensional protein identification technology mass spectrometry, we found that arylomycin treatment inhibits the proper extracytoplasmic localization of many proteins, both those that appear to be SPase substrates and several that do not. The identified proteins are involved in a broad range of extracytoplasmic processes and include a number of virulence factors. The effects of arylomycin on several processes required for virulence were then individually examined, and we found that, at even sub-MIC levels, the arylomycins potently inhibit flagellation, motility, biofilm formation, and the dissemination of antibiotic resistance via HGT. Thus, we conclude that the arylomycins represent promising novel therapeutics with the potential to eradicate infections while simultaneously reducing virulence and the dissemination of resistance.

| S-EPMC6355593 | biostudies-other

Boosted Photocatalytic Activities of Ag2CrO4 through Eu3+-Doping Process.

Project description:Ag2CrO4 is a representative member of a family of Ag-containing semiconductors with highly efficient visible-light-driven responsive photocatalysts. The doping process with Eu3+ is known to effectively tune their properties, thus opening opportunities for investigations and application. Here, we report the enhancement of the photocatalytic activity and stability of Ag2CrO4 by introducing Eu3+cations. The structural, electronic, and photocatalytic properties of Ag2CrO4:xEu3+ (x = 0, 0.25, 0.5, 1%) synthesized using the coprecipitation method were systematically discussed, and their photodegradation activity against rhodamine B (RhB), ciprofloxacin hydrochloride monohydrate (CIP), and 4-nitrophenol (4-NP) was evaluated. Structural analyses reveal a short-range symmetry breaking in the Ag2CrO4 lattice after Eu3+ doping, influencing the material morphology, size, and electronic properties. XPS analysis confirmed the incorporation of Eu3+ and alteration of the surface oxygen species. Furthermore, photoluminescence measurements indicated that the doping process was responsible for reducing recombination processes. The sample doped with 0.25% Eu3+ exhibited superior photocatalytic performance compared to pure Ag2CrO4. Scavenger experiments revealed an increase in the degradation via •OH reactive species for the sample doped with 0.25% Eu3+. DFT calculations provided atomic-scale insights into the structural and electronic changes induced by the Eu3+ doping process in the Ag2CrO4 host lattice. This study confirms that Eu3+ doping alters the band structure, enabling different degradation paths and boosting the separation/transfer of photogenerated charges, thereby improving the overall photocatalytic performance.

| S-EPMC11339825 | biostudies-literature

Nutrients mediate caffeine inhibition of Escherichia coli.

Project description:The consumption of coffee and other caffeinated drinks is increasingly popular across the globe. In the United States, 90% of adults consume at least one caffeinated beverage a day. While caffeine consumption of up to 400 mg/d is not generally associated with negative effects on human health, the impact of caffeine on the gut microbiome and individual gut microbiota remains unclear. We examined the effect of caffeine on the growth rate of Escherichia coli, a bacterium commonly found in the human gut, when grown aerobically or anaerobically in nutrient-rich or minimal medium. A significant negative correlation was observed between caffeine concentration and growth rate under all conditions, suggesting that caffeine can act as an antimicrobial agent when ingested. Caffeine reduced growth rates significantly more in nutrient-poor, but not in anoxic, conditions. Given the highly variable nutrient and oxygen conditions of the gut, these results suggest a need to further explore caffeine's inhibitory effects on the gut microbiome and its relation to human health.

| S-EPMC10472513 | biostudies-literature

Insights into the Synthesis Mechanisms of Ag-Cu3P-GaP Multicomponent Nanoparticles.

Project description:Metal-semiconductor nanoparticle heterostructures are exciting materials for photocatalytic applications. Phase and facet engineering are critical for designing highly efficient catalysts. Therefore, understanding processes occurring during the nanostructure synthesis is crucial to gain control over properties such as the surface and interface facets' orientations, morphology, and crystal structure. However, the characterization of nanostructures after the synthesis makes clarifying their formation mechanisms nontrivial and sometimes even impossible. In this study, we used an environmental transmission electron microscope with an integrated metal-organic chemical vapor deposition system to enlighten fundamental dynamic processes during the Ag-Cu3P-GaP nanoparticle synthesis using Ag-Cu3P seed particles. Our results reveal that the GaP phase nucleated at the Cu3P surface, and growth proceeded via a topotactic reaction involving counter-diffusion of Cu+ and Ga3+ cations. After the initial GaP growth steps, the Ag and Cu3P phases formed specific interfaces with the GaP growth front. GaP growth proceeded by a similar mechanism observed for the nucleation involving the diffusion of Cu atoms through/along the Ag phase toward other regions, followed by the redeposition of Cu3P at a specific Cu3P crystal facet, not in contact with the GaP phase. The Ag phase was essential for this process by acting as a medium enabling the efficient transport of Cu atoms away from and, simultaneously, Ga atoms toward the GaP-Cu3P interface. This study shows that enlightening fundamental processes is critical for progress in synthesizing phase- and facet-engineered multicomponent nanoparticles with tailored properties for specific applications, including catalysis.

| S-EPMC10134500 | biostudies-literature