Synergistic antibacterial effect of copper and silver nanoparticles and their mechanism of action.

Bacterial infections are one of the leading causes of death worldwide. In the case of topical bacterial infections such as wound infections, silver (Ag) has historically been one of the most widely used antibacterials. However, scientific publications have demonstrated the adverse effects of silver on human cells, ecotoxicity and insufficient antibacterial effect for the complete elimination of bacterial infections.

Multi-generation exposure to polystyrene nanoplastics showed no major adverse effects in Daphnia magna.

Long-term impacts of plastics exposure to organisms, especially to the smallest plastics fraction, nanoplastics (NPs; ≤1 μm), are yet to be fully understood. The data concerning multiple generations are especially rare - an exposure scenario that is the most relevant from the standpoint of environmental reality aspect. Using Pd-doped 200 nm polystyrene NPs, which allowed for quantification of NPs in trace concentrations, the aim of the study was to evaluate the multigenerational impact of NPs for the freshwater crustacean Daphnia magna.

Visible-Light Active Flexible and Durable Photocatalytic Antibacterial Ethylene-co-vinyl Acetate-Ag/AgCl/α-FeO Composite Coating.

When particles are mixed in polymer, particle surfaces become passivated by polymer matrix, leading to significantly reduced photocatalytic and, thus, also reduced antibacterial activity, as the catalytic particles become isolated from the outer environment and microorganisms reaching the surface. Herein, we demonstrate a facile and rapid approach for coating preparation at room temperature, yielding good adhesion of particles in combination with the particles' interface location. Flexible ethylene-co-vinyl acetate Ag/AgCl/α-FeO composite coatings were prepared by the spin-coating method.

Stable Isotope Tracing Uncovers Reduced γ/β-ATP Turnover and Metabolic Flux Through Mitochondrial-Linked Phosphotransfer Circuits in Aggressive Breast Cancer Cells.

Changes in dynamics of ATP γ- and β-phosphoryl turnover and metabolic flux through phosphotransfer pathways in cancer cells are still unknown. Using O phosphometabolite tagging technology, we have discovered phosphotransfer dynamics in three breast cancer cell lines: MCF7 (non-aggressive), MDA-MB-231 (aggressive), and MCF10A (control). Contrary to high intracellular ATP levels, the O labeling method revealed a decreased γ- and β-ATP turnover in both breast cancer cells, compared to control.

Cubic Iron Core-Shell Nanoparticles Functionalized to Obtain High-Performance MRI Contrast Agents.

Nanoparticles with SiO2 coating were synthesized to have a cubic iron core. These were found to have saturation magnetization very close to the highest possible value of any iron-containing nanoparticles and the bulk iron saturation magnetization. The in vitro toxicology studies show that they are highly biocompatible and possess better MRI contrast agent potential than iron oxide NPs.

Long-Term Toxicity of Gadolinium to the Freshwater Crustacean Daphnia magna.

The lanthanides are considered emerging contaminants but information on their long-term toxicity to aquatic species under environmentally relevant conditions is scarce. We aimed to fill this gap by evaluating the long-term adverse effects of gadolinium on the freshwater model-crustacean Daphnia magna. The exposure of D.

Long Term Exposure to Virgin and Recycled LDPE Microplastics Induced Minor Effects in the Freshwater and Terrestrial Crustaceans and .

The effects of microplastics (MP) are extensively studied, yet hazard data from long-term exposure studies are scarce. Moreover, for sustainable circular use in the future, knowledge on the biological impact of recycled plastics is essential. The aim of this study was to provide long-term toxicity data of virgin vs recycled (mechanical recycling) low density polyethylene (LDPE) for two commonly used ecotoxicity models, the freshwater crustacean and the terrestrial crustacean .

Colon cancer cell differentiation by sodium butyrate modulates metabolic plasticity of Caco-2 cells via alteration of phosphotransfer network.

The ability of butyrate to promote differentiation of cancer cells has important implication for colorectal cancer (CRC) prevention and therapy. In this study, we examined the effect of sodium butyrate (NaBT) on the energy metabolism of colon adenocarcinoma Caco-2 cells coupled with their differentiation. NaBT increased the activity of alkaline phosphatase indicating differentiation of Caco-2 cells.

Surface carboxylation or PEGylation decreases CuO nanoparticles' cytotoxicity to human cells in vitro without compromising their antibacterial properties.

Clinical use of CuO nanoparticles (NPs) as antibacterials can be hampered by their toxicity to human cells. We hypothesized that certain surface functionalizations of CuO NPs may render NPs toxic to bacteria, but still be relatively harmless to human cells. To control this hypothesis, the toxicity of differently functionalized CuO NPs to bacteria Escherichia coli vs human cells (THP-1 macrophages and HACAT keratinocytes) was compared using similar conditions and end points.

Hazard evaluation of polystyrene nanoplastic with nine bioassays did not show particle-specific acute toxicity.

Plastic is a wide-spread pollutant and must be evaluated for potential adverse effects of its breakdown product, microplastic (≤5 mm) along with its subfraction, nanoplastic (1-100 nm). Risk assessment of pollutants cannot be conducted without their toxicity (dose-response) data. In this study, toxicity of polystyrene nanoplastics (PS-NPL) was evaluated using 8 acute and 1 subchronic toxicity assays with 10 organisms of different biological complexity (bacteria, yeast, algae, protozoans, mammalian cells in vitro, crustaceans, midge larvae).

Toxicity of differently sized and charged silver nanoparticles to yeast BY4741: a nano-biointeraction perspective.

In the current study, we evaluated the modulatory effects of size and surface coating/charge of AgNPs on their toxicity to a unicellular yeast BY4741 - a fungal model. For that, the toxicity of a set of 10 and 80 nm citrate-coated (negatively charged) and branched polyethylenimine (bPEI) coated (positively charged) AgNPs was evaluated in parallel with AgNO as ionic control. Yeast cells were exposed to different concentrations of studied compounds in deionized water for 24 h at 30 °C and evaluated for the viability by the post-exposure colony-forming ability.

Antimicrobial potency of differently coated 10 and 50 nm silver nanoparticles against clinically relevant bacteria Escherichia coli and Staphylococcus aureus.

Silver nanoparticles (nanoAg) are effective antimicrobials and promising alternatives to traditional antibiotics. This study aimed at evaluating potency of different nanoAg against healthcare infections associated bacteria: Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. A library of differently coated nanoAg of two different sizes (10 and 50 nm) were prepared using coating agents poly-L-Lysine (PLL), cetyltrimethyl-ammonium bromide (CTAB), citrate (CIT), polyvinyl-pyrrolidone (PVP), polysorbate 80 (Tween 80), and dioctyl-sodium sulfosuccinate (AOT).

Rapid in situ assessment of Cu-ion mediated effects and antibacterial efficacy of copper surfaces.

Release of metal ions from metal-based surfaces has been considered one of the main drivers of their antimicrobial activity. Here we describe a method that enables parallel assessment of metal ion release from solid metallic surfaces and antimicrobial efficacy of these surfaces in a short time period. The protocol involves placement of a small volume of bioluminescent bacteria onto the tested surface and direct measurement of bioluminescence at various time points.

UVA-induced antimicrobial activity of ZnO/Ag nanocomposite covered surfaces.

Application of efficient antimicrobial surfaces has been estimated to decrease both, the healthcare-associated infections and the spread of antibiotic-resistant bacteria. In this paper, we prepared ZnO and ZnO/Ag nanoparticle covered surfaces and evaluated their antimicrobial efficacy towards a Gram-negative bacterial model (Escherichia coli), a Gram-positive bacterial model (Staphylococcus aureus) and a fungal model (Candida albicans) in the dark and under UVA illumination. The surfaces were prepared by spin coating aliquots of ZnO and ZnO/Ag nanoparticle suspensions onto glass substrates.

Uptake and transcytosis of functionalized superparamagnetic iron oxide nanoparticles in an in vitro blood brain barrier model.

Two major hurdles in nanomedicine are the limited strategies for synthesizing stealth nanoparticles and the poor efficacy of the nanoparticles in translocating across the blood brain barrier (BBB). Here we examined the uptake and transcytosis of iron oxide nanoparticles (IONPs) grafted with biomimetic phosphorylcholine (PC) brushes in an in vitro BBB model system, and compared them with bare, PEG or PC-PEG mixture grafted IONPs. Hyperspectral imaging indicated IONP co-localization with cells.

Evaluation of the effect of test medium on total Cu body burden of nano CuO-exposed Daphnia magna: A TXRF spectroscopy study.

Toxicity of Cu and Cu-based nanoparticles (NPs) to aquatic biota is usually mitigated in natural freshwater compared to organics-free artificial freshwater. The main aim of this study was to evaluate whether mitigated toxicity is accompanied by lower total copper body burden in the freshwater crustacean Daphnia magna and whether CuO NPs are more hazardous in this aspect than soluble Cu salts. Total copper body burden in different media (OECD202 artificial freshwater and two natural freshwaters) was measured by a relatively novel technique - total reflection X-ray fluorescence (TXRF) spectroscopy - which proved suitable for the analysis of individual juvenile daphnids.

Assessment of the hazard of nine (doped) lanthanides-based ceramic oxides to four aquatic species.

The risk of environmental pollution with rare earth oxides rises in line with increasing application of these compounds in different sectors. However, data on potential environmental hazard of lanthanides is scarce and concerns mostly Ce and Gd. In this work, the aquatic toxicity of eight doped lanthanide-based ceramic oxides (CeGdO, LaFeO, GdCoO, LaCoO, (LaSr)MnO, CePrO, (LaSr)CoO, LaNiO) and one non-doped oxide (CeO) with primary size from 23 to 590nm were evaluated in four short-term laboratory assays with freshwater crustaceans and duckweeds.

Toxicity of Nine (Doped) Rare Earth Metal Oxides and Respective Individual Metals to Aquatic Microorganisms Vibrio fischeri and Tetrahymena thermophila.

Despite the increasing use of rare earth elements (REEs) and oxides (REOs) in various technologies, the information on their ecotoxicological hazard is scarce. Here, the effects of La, Ce, Pr, Nd, Gd, CeO₂, and eight doped REOs to marine bacteria and freshwater protozoa were studied in parallel with REO dopant metals (Co, Fe, Mn, Ni, Sr). The highest concentrations of REOs tested were 100 mg/L with protozoa in deionized water and 500 mg/L with bacteria in 2% NaCl.

Potency of (doped) rare earth oxide particles and their constituent metals to inhibit algal growth and induce direct toxic effects.

Use of rare earth elements (REEs) has increased rapidly in recent decades due to technological advances. It has been accompanied by recurring rare earth element anomalies in water bodies. In this work we (i) studied the effects of eight novel doped and one non-doped rare earth oxide (REO) particles (aimed to be used in solid oxide fuel cells and gas separation membranes) on algae, (ii) quantified the individual adverse effects of the elements that constitute the (doped) REO particles and (iii) attempted to find a discernible pattern to relate REO particle physicochemical characteristics to algal growth inhibitory properties.

A Highly Active Endo-Levanase BT1760 of a Dominant Mammalian Gut Commensal Bacteroides thetaiotaomicron Cleaves Not Only Various Bacterial Levans, but Also Levan of Timothy Grass.

Bacteroides thetaiotaomicron, an abundant commensal of the human gut, degrades numerous complex carbohydrates. Recently, it was reported to grow on a β-2,6-linked polyfructan levan produced by Zymomonas mobilis degrading the polymer into fructooligosaccharides (FOS) with a cell surface bound endo-levanase BT1760. The FOS are consumed by B.

Bacterial polysaccharide levan as stabilizing, non-toxic and functional coating material for microelement-nanoparticles.

Levan, fructose-composed biopolymer of bacterial origin, has potential in biotechnology due to its prebiotic and immunostimulatory properties. In this study levan synthesized by levansucrase from Pseudomonas syringae was thoroughly characterized and used as multifunctional biocompatible coating material for microelement-nanoparticles (NPs) of selenium, iron and cobalt. Transmission electron microscopy (TEM), hydrodynamic size measurements (DLS) and X-ray photoelectron spectroscopy (XPS) showed the interaction of levan with NPs.

Toxicity of 11 Metal Oxide Nanoparticles to Three Mammalian Cell Types In Vitro.

The knowledge on potential harmful effects of metallic nanomaterials lags behind their increased use in consumer products and therefore, the safety data on various nanomaterials applicable for risk assessment are urgently needed. In this study, 11 metal oxide nanoparticles (MeOx NPs) prepared using flame pyrolysis method were analyzed for their toxicity against human alveolar epithelial cells A549, human epithelial colorectal cells Caco2 and murine fibroblast cell line Balb/c 3T3. The cell lines were exposed for 24 h to suspensions of 3-100 μg/mL MeOx NPs and cellular viability was evaluated using.

Size-dependent toxicity of silver nanoparticles to bacteria, yeast, algae, crustaceans and mammalian cells in vitro.

The concept of nanotechnologies is based on size-dependent properties of particles in the 1-100 nm range. However, the relation between the particle size and biological effects is still unclear. The aim of the current paper was to generate and analyse a homogenous set of experimental toxicity data on Ag nanoparticles (Ag NPs) of similar coating (citrate) but of 5 different primary sizes (10, 20, 40, 60 and 80 nm) to different types of organisms/cells commonly used in toxicity assays: bacterial, yeast and algal cells, crustaceans and mammalian cells in vitro.

Degradation of Fructans and Production of Propionic Acid by Bacteroides thetaiotaomicron are Enhanced by the Shortage of Amino Acids.

Bacteroides thetaiotaomicron is commonly found in the human colon and stabilizes its ecosystem by catabolism of various polysaccharides. A model of cross-talk between the metabolism of amino acids and fructans in B. thetaiotaomicron was proposed.