Contribution, Composition, and Structure of EPS by In Vivo Exposure to Elucidate the Mechanisms of Nanoparticle-Enhanced Bioremediation to Metals.

Bacterial extracellular polymeric substances (EPS) have been recently found to contribute most for metal removal in nanoenhanced bioremediation. However, the mechanism by which NPs affect EPS-metal interactions is not fully known. Here, sp.

Nanoparticles as antibiotic-delivery vehicles (ADVs) overcome resistance by MRSA and other MDR bacterial pathogens: The grenade hypothesis.

Objectives: The aim of this study was to examine how the concentrated delivery of less effective antibiotics, such as the β-lactam penicillin G, by linkage to nanoparticles (NPs), could influence the killing efficiency against various pathogenic bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and other multidrug resistant (MDR) strains.

Methods: The β-lactam antibiotic penicillin G (PenG) was passively sorbed to fluorescent polystyrene NPs (20nm) that were surface-functionalized with carboxylic acid (COO-NPs) or sulfate groups (SO-NPs) to form a PenG-NP complex. Antimicrobial activities of PenG-NPs were evaluated against Gram-negative and Gram-positive bacteria, including antibiotic resistant strains.

Improved metal remediation using a combined bacterial and nanoscience approach.

Polyvinylpyrrolidone (PVP) coated iron oxide nanoparticles (NPs) were used to explore the potential for improved bioremediation of metals by interaction with the Gram-negative bacterium Halomonas sp. The combined approach improved metal removal and shortened metal remediation times (approx. 100% removal of Pb after 24 h, of Cd after 48 h) compared with bacteria- or NP-only controls.

Gold Nanoparticles with Antibiotic-Metallopolymers toward Broad-Spectrum Antibacterial Effects.

Bacterial infection has evolved into one of the most dangerous global health crises. Designing potent antimicrobial agents that can combat drug-resistant bacteria is essential for treating bacterial infections. In this paper, a strategy to graft metallopolymer-antibiotic bioconjugates on gold nanoparticles is developed as an antibacterial agent to fight against different bacterial strains.

Recyclable magnetic nanoparticles grafted with antimicrobial metallopolymer-antibiotic bioconjugates.

Over-prescription and improper use of antibiotics has led to the emergence of bacterial resistance, posing a major threat to public health. There has been significant interest in the development of alternative therapies and agents to combat antibiotic resistance. We report the preparation of recyclable magnetic iron oxide nanoparticles grafted with charged cobaltocenium-containing metallopolymers by surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization.

A novel method for the synergistic remediation of oil-water mixtures using nanoparticles and oil-degrading bacteria.

Releases of crude oil and other types of oil from numerous sources can impose catastrophic physical, chemical, and biological effects on aquatic ecosystems. While currently-used oil removal techniques possess many advantages, they have inherent limitations, including low removal efficiencies and waste disposal challenges. The present study quantified the synergistic interactions of polyvinylpyrrolidone (PVP) coated magnetite nanoparticles (NP) and oil-degrading bacteria for enhanced oil removal at the laboratory scale.

Charged Metallopolymer-Grafted Silica Nanoparticles for Antimicrobial Applications.

Inappropriate and frequent use of antibiotics has led to the development of antibiotic-resistant bacteria, which cause infectious diseases that are difficult to treat. With the rising threat of antibiotic resistance, the need to develop effective new antimicrobial agents is prominent. We report antimicrobial metallopolymer nanoparticles, which were prepared by surface-initiated reversible addition-fragmentation chain transfer polymerization of a cobaltocenium-containing methacrylate monomer from silica nanoparticles.

Trio Act of Boronolectin with Antibiotic-Metal Complexed Macromolecules toward Broad-Spectrum Antimicrobial Efficacy.

Bacterial infections, particularly by Gram-negative pathogens, have become a serious threat to global healthcare due to the diminishing effectiveness of existing antibiotics. We report a nontraditional therapy to combine three components in one macromolecular system, in which boronic acid adheres to peptidoglycan or lipopolysaccharide via boron-polyol based boronolectin chemistry, cationic metal polymer frameworks interact with negatively charged cell membranes, and β-lactam antibiotics are reinstated with enhanced vitality to attack bacteria via evading the detrimental enzyme-catalyzed hydrolysis. These macromolecular systems exhibited high efficacy in combating pathogenic bacteria, especially Gram-negative strains, due to synergistic effects of multicomponents on interactions with bacterial cells.

Complete Genome Sequence of ATCC 43942.

ATCC 43942 has the potential to synthesize a plethora of metabolites which are of clinical and agricultural significance in response to environmental triggers. The complete genomic sequence of ATCC 43942 is reported herein, contributing to the knowledge base of strains in the genus.

Aflatoxin-Exposure of Vibrio gazogenes as a Novel System for the Generation of Aflatoxin Synthesis Inhibitors.

Aflatoxin is a mycotoxin and a secondary metabolite, and the most potent known liver carcinogen that contaminates several important crops, and represents a significant threat to public health and the economy. Available approaches reported thus far have been insufficient to eliminate this threat, and therefore provide the rational to explore novel methods for preventing aflatoxin accumulation in the environment. Many terrestrial plants and microbes that share ecological niches and encounter the aflatoxin producers have the ability to synthesize compounds that inhibit aflatoxin synthesis.

Long-term antihypertensive effects of far-infrared ray irradiated from wooden board in spontaneously hypertensive rats.

Background: Far-infrared ray (FIR) has been widely used in promoting health and has been shown to exert beneficial effects in vascular function. The non-thermal effect of FIR has been found to play a significant role in the protective effect on some vascular-related diseases, but its protective effects and use against hypertension have not been clearly presented.

Methods: In the present study, by using a wooden board coated with FIR-irradiated materials, we evaluated the long-term antihypertensive effect on spontaneously hypertensive rats (SHRs) in the environment in contact with the FIR-irradiated wooden board.

Engineering nanoparticles to silence bacterial communication.

The alarming spread of bacterial resistance to traditional antibiotics has warranted the study of alternative antimicrobial agents. Quorum sensing (QS) is a chemical cell-to-cell communication mechanism utilized by bacteria to coordinate group behaviors and establish infections. QS is integral to bacterial survival, and therefore provides a unique target for antimicrobial therapy.

Functionalised nanoparticles complexed with antibiotic efficiently kill MRSA and other bacteria.

Antibiotic-resistant bacterial infections are a vexing global health problem and have rendered ineffective many previously-used antibiotics. Here we demonstrate that antibiotic-linkage to surface-functionalized silica nanoparticles (sNP) significantly enhances their effectiveness against Escherichia coli, and Staphylococcus aureus, and even methicillin-resistant S. aureus (MRSA) strains that are resistant to most antibiotics.

Antimicrobial metallopolymers and their bioconjugates with conventional antibiotics against multidrug-resistant bacteria.

Bacteria are now becoming more resistant to most conventional antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA), a complex of multidrug-resistant Gram-positive bacterial strains, has proven especially problematic in both hospital and community settings by deactivating conventional β-lactam antibiotics, including penicillins, cephalosporins, and carbapenems, through various mechanisms, resulting in increased mortality rates and hospitalization costs. Here we introduce a class of charged metallopolymers that exhibit synergistic effects against MRSA by efficiently inhibiting activity of β-lactamase and effectively lysing bacterial cells.

Surface-functionalization effects on uptake of fluorescent polystyrene nanoparticles by model biofilms.

A study was conducted to investigate the role of nanoparticle (NP) surface functionalization/charge on their uptake by biofilms. Biofilms, bacterial colonies attached to surfaces via extracellular polymers, are effective at removing suspended nanomaterials from the aqueous phase. However, the mechanisms regulating particle uptake are unknown.

Robust antimicrobial compounds and polymers derived from natural resin acids.

We report novel robust resin acid-derived antimicrobial agents that exhibit excellent antimicrobial activities against a broad spectrum of bacteria (6 Gram-positive and 7 Gram-negative) with selective lysis of microbial membranes over mammalian membranes. Our results indicate that hydrophobicity and unique structures of resin acids can be determining factors in dictating the antimicrobial activity.

A permanent optical storage medium exhibiting ultrahigh contrast, superior stability, and a broad working wavelength regime.

In this paper we demonstrate an optical storage medium having advantages of ultrahigh contrast, superior stability, and broadband working wavelengths. Combining a single shot of deep-ultraviolet (UV) laser illumination with a Au particle-assisted etching process, we formed broadband antireflective, one-dimensional silicon nanowire arrays (SiNWs) with selectively at specific positions. Optical measurements and three-dimensional finite-difference time domain (3D-FDTD) simulations revealed ultrahigh reflection contrast between the Au and the SiNWs for both far- and near-field regimes.

One-shot deep-UV pulsed-laser-induced photomodification of hollow metal nanoparticles for high-density data storage on flexible substrates.

In this paper, we report a new optical data storage method: photomodification of hollow gold nanoparticle (HGN) monolayers induced by one-shot deep-ultraviolet (DUV) KrF laser recording. As far as we are aware, this study is the first to apply HGNs in optical data storage and also the first to use a recording light source for the metal nanoparticles (NPs) that is not a surface plasmon resonance (SPR) wavelength. The short wavelength of the recording DUV laser improved the optical resolution dramatically.

Rapid screening of quorum-sensing signal N-acyl homoserine lactones by an in vitro cell-free assay.

A simple, sensitive, and rapid cell-free assay system was developed for detection of N-acyl homoserine lactone (AHL) autoinducers involved in bacterial quorum sensing (QS). The present approach improves upon previous whole-cell biosensor-based approaches in its utilization of a cell-free assay approach to conduct bioassays. The cell-free assay was derived from the AHL biosensor bacterium Agrobacterium tumefaciens NTL4(pCF218)(pCF372), allowing the expression of beta-galactosidase upon addition of exogenous AHLs.

Spectroscopic characterization of the ferric states of Amphitrite ornata dehaloperoxidase and Notomastus lobatus chloroperoxidase: His-ligated peroxidases with globin-like proximal and distal properties.

Amphitrite ornata dehaloperoxidase (DHP) and Notomastus lobatus chloroperoxidase (NCPO) catalyze the peroxide-dependent dehalogenation of halophenols and halogenation of phenols, respectively. Both enzymes have histidine (His) as their proximal heme iron ligand. Crystallographic examination of DHP revealed that it has a globin fold [M.