UNASSIGNED: Enterococcus faecalis (E. faecalis) is one of the main pathogens responsible for refractory root canal infections in the teeth and shows resistance against various antibacterial managements. Effective control of E. faecalis infection is a prerequisite for successful treatment of refractory apical periodontitis. This study aimed to analyze the antibacterial activity and mechanisms of Au@Ag nanoparticles (NPs) combined with photothermal therapy (PTT) against the original and Ag+-resistant E. faecalis.
UNASSIGNED: Au@AgNPs with optimal shell thicknesses were synthesized and characterized. The antibacterial activity of Au@AgNPs with PTT against the original or Ag+-resistant E. faecalis was evaluated, and the antibiofilm activity was tested on E. faecalis biofilm on the dentin of teeth. The potential antibacterial mechanisms of Au@AgNPs combined with PTT against E. faecalis have also been studied. Moreover, its influence on dentin microhardness and cytotoxicity was assessed.
UNASSIGNED: This study revealed that Au@AgNPs combined with PTT showed enhanced antibacterial and antibiofilm effects, no negative effects on dentin microhardness, and low cytotoxicity toward human periodontal ligament cells (hPDLCs). Moreover, Au@AgNPs combined with PTT effectively inhibited the growth of Ag+-resistant E. faecalis. Its antibacterial effects may be exerted through the release of silver ions (Ag+), destruction of the cell membrane, production of reactive oxygen species (ROS) and inhibition of adenosine triphosphate (ATP) production. Hyperthermia generated by Au@AgNPs with PTT reduced membrane fluidity and enhanced Ag+ sensitivity by downregulating fabF expression. The upregulated expression of heat shock genes demonstrated that the Ag+ released from Au@AgNPs compromised the heat adaptation of E. faecalis.
UNASSIGNED: PTT significantly enhanced Ag+ sensitivity of the original and Ag+-resistant E. faecalis. Au@AgNPs combined with PTT may have the potential to be developed as a new antibacterial agent to control E. faecalis infections in teeth.

Silver nanoparticles (AgNPs) are known to affect the physiology and morphology of plants in various ways, but the exact mechanism by which they interact with plant cells remains to be elucidated. An unresolved question of silver nanotoxicology is whether the interaction is triggered by the physical features of the particles, or by silver ions leached from their surface. In this study, we germinated and grew Arabidopsis thaliana seedlings in synthetic medium supplemented with sub-morbid concentrations (4 μg/mL) of AgNPs and silver nitrate (AgNO3). This treatment led to in planta accumulation of 106 μg/g and 97 μg/g of silver in the AgNO3- and AgNP-exposed seedlings, respectively. Despite the statistically indistinguishable silver accumulation, RNA sequencing data demonstrated distinct changes in the transcriptome of the AgNP-exposed, but not in the AgNO3-exposed plants. AgNP exposure induced changes in the expression of genes involved in immune response, cell wall organization, photosynthesis and cellular defense against reactive oxygen species. AgNO3 exposure, on the other hand, caused the differential expression of only two genes, neither of which belonged to any AgNP-enriched gene ontology categories. Moreover, AgNP exposure led to a 39% reduction (p < 0.001) in total chlorophyll concentration relative to untreated plants which was associated with a 56.9% and 56.2% drop (p < 0.05) in carbon assimilation rate at ambient and saturating light, respectively. Stomatal conductance was not significantly affected by AgNP exposure, and limitations to carbon assimilation, as determined through analysis of light and carbon dioxide (A/Ci) curves, were attributed to rates of electron transport, maximum carboxylation rates and triose phosphate use. AgNO3-exposure, on the other hand, did not lead to significant reduction either in chlorophyll concentration or in carbon assimilation rate. Given these data, we propose that the impact of AgNPs cannot be simply attributed to the presence of the metal in plants, but is innate to the particulate nature of nanosilver.

Silver ions (Ag+) exist widely in various areas of human life, and the food contamination caused by them poses a serious threat to human health. Among the numerous methods used for the detection of Ag+, fluorescence and colorimetric analysis have attracted much attention due to their inherent advantages, such as high sensitivity, simple operation, short time, low cost and visualized detection. In this work, Pd/Pt nanoflowers (NFs) specifically responsive to Ag+ were synthesized in a simple way to oxidize o-phenylenediamine (OPD) into 2,3-diaminophenazine (DAP). The interaction of Ag+ with the surface of Pd/Pt NFs inhibits the catalytic activity of Pd/Pt NFs towards the substrate OPD. A novel dual-channel nanosensor was constructed for the detection of Ag+, using the fluorescence intensity and UV-vis absorption intensity of DAP as output signals. This dual-mode analysis combines their respective advantages to significantly improve the sensitivity and accuracy of Ag+ detection. The results showed that the limit of detection was 5.8 nM for the fluorescence channel and 46.9 nM for the colorimetric channel, respectively. Moreover, the developed platform has been successfully used for the detection of Ag+ in real samples with satisfactory recoveries, which is promising for the application in the point-of-care testing of Ag+ in the field of food safety.

OBJECTIVE: Silver nanoparticles (AgNPs) are considered to be a very significant and intriguing type within the category of metallic nanoparticles, particularly in the context of their involvement in biological applications. The objective of this research is to use the green synthesis method in order to synthesize AgNPs by using the leaf extract of C. rotundata. Furthermore, the study aims to evaluate the antioxidant and anti-inflammatory properties of these nanoparticles.
METHODS: Fresh and healthy specimens of C. rotundata were gathered from Palk Bay, Tamil Nadu, India, and afterward subjected to a thorough washing process using tap water. The cleaned materials were air-dried and then fragmented into small bits and finely ground. The ethanolic extract of seagrass was then combined with a solution containing 1 millimolar (mM) silver nitrate (AgNo3). The decrease of silver ions in the solution was frequently measured using a UV-visible spectrophotometer. Synthesized AgNPs were investigated for antioxidants by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and anti-inflammatory activity was measured by protein-denaturation assay.
RESULTS: The use of C. rotundata leaf extract in the green synthesis of AgNPs, in the presence of 1 mM AgNO3, led to a noticeable alteration in the colour of the mixture, transitioning from a pale hue to a brown shade. This change in colour serves as evidence of the reduction of AgNo3 ions to silver ions, thereby facilitating the creation of AgNPs. The duration of the bio-reduction process of silver ions in the reaction mixture was observed to be two hours. The antioxidant and anti-inflammatory activity showed promising activity for AgNPs.
CONCLUSIONS: This study concluded that C. rotundata had antioxidant capabilities, and AgNPs derived from C. rotundata have potential use in pharmaceuticals and medication administration.

Addressing the growing need for environmentally friendly fungicides in agriculture, this study explored the potential of biopolymer microparticles loaded with metal ions as a novel approach to combat fungal pathogens. Novel alginate microspheres and chitosan/alginate microcapsules loaded with zinc or with zinc and silver ions were prepared and characterized (microparticle size, morphology, topography, encapsulation efficiency, loading capacity, and swelling behavior). Investigation of molecular interactions in microparticles using FTIR-ATR spectroscopy exhibited complex interactions between all constituents. Fitting to the simple Korsmeyer-Peppas empirical model revealed the rate-controlling mechanism of metal ions release from microparticles is Fickian diffusion. Lower values of the release constant k imply a slower release rate of Zn2+ or Ag+ ions from microcapsules compared to that of microspheres. The antimicrobial potential of the new formulations against the fungus Botrytis cinerea was evaluated. When subjected to tests against the fungus, microspheres exhibited superior antifungal activity especially those loaded with both zinc and silver ions, reducing fungal growth up to 98.9% and altering the hyphal structures. Due to the slower release of metal ions, the microcapsule formulations seem suitable for plant protection throughout the growing season. The results showed the potential of these novel microparticles as powerful fungicides in agriculture.

Background Silver possesses cytotoxic properties against many microorganisms and is regularly used in wound care. Current evidence supporting the use of one type of silver-containing wound dressing (SCWD) is insufficient. Materials and methods To examine the ability of selected SCWDs to inhibit the growth of two strains of bacteria (Escherichia coli and Staphylococcus aureus) commonly found in wounds, an in vitro wound model was used. Bacteria were applied to the surface of nutrient agar, and a piece of each SCWD was applied to the bacteria. The plates were incubated at 37°C overnight. The zone of inhibition (ZI) around each SCWD was measured in cm2. Results The mean ZI for Acticoat Flex-3 on E. coli was 1.59 ± 0.15 cm2, which was significantly greater than that observed for Aquacel Ag (p<0.001), Mepilex Ag (p<0.0001), Mepitel Ag (p<0.001), Optifoam (p<0.0001), and Tegaderm Alginate Ag (p<0.01), but statistically indistinguishable from Maxorb II Ag. The mean ZI on S. aureus was 1.21 ± 0.16 cm2, which was greater than Aquacel Ag (p<0.05), Mepilex (p<0.0001), Optifoam (p<0.0001), and Tegaderm Alginate Ag (p<0.05), but statistically indistinguishable from Maxorb II Ag or Mepitel Ag. Conclusion Of the SCWDs tested, Acticoat Flex-3 demonstrated the most robust antimicrobial effect. Herein, we show that Acticoat Flex-3 may provide the most wound protection against bacterial infection. In conclusion, these data provide clinicians with additional independent evidence to inform their clinical practice on the use of specific wound dressings.

BACKGROUND: Hydroxyapatites (HAp) are widely used as medical preparations for e.g., bone replacement or teeth implants. Incorporation of various substrates into HAp structures could enhance its biological properties, like biocompatibility or antimicrobial effects. Silver ions possess high antibacterial and antifungal activity and its application as HAp dopant might increase its clinical value.
RESULTS: New silicate-substituted hydroxyapatites (HAp) doped with silver ions were synthesized via hydrothermal methods. The crystal structure of HAp was investigated by using the X-ray powder diffraction. Antifungal activity of silver ion-doped HAp (with 0.7 mol%, 1 mol% and 2 mol% of dopants) was tested against the yeast-like reference and clinical strains of Candida albicans, C. glabrata, C. tropicalis, Rhodotorula rubra, R. mucilaginosa, Cryptococcus neoformans and C. gattii. Spectrophotometric method was used to evaluate antifungal effect of HAp in SD medium. It was shown that already the lowest dopant (0.7 mol% of Ag+ ions) significantly reduced fungal growth at the concentration of 100 µg/mL. Increase in the dopant content and the concentration of HAp did not cause further growth inhibition. Moreover, there were some differences at the tolerance level to Ag+ ion-doped HAp among tested strains, suggesting strain-specific activity.
CONCLUSIONS: Preformed studies confirm antimicrobial potential of hydroxyapatite doped with silver. New Ag+ ion-HAp material could be, after further studies, considered as medical agent with antifungal properties which lower the risk of a surgical-related infections.

Silver nanoparticles (AgNPs) are of great interest due to their antimicrobial properties, but their reactivity and toxicity pose a significant risk to aquatic ecosystems. In biological systems, AgNPs tend to aggregate and dissolve, so they are often stabilized by agents that affect their physicochemical properties. In this study, microalga Chlorella vulgaris was used as a model organism to evaluate the effects of AgNPs in aquatic habitats. Algae were exposed to AgNPs stabilized with citrate and cetyltrimethylammonium bromide (CTAB) agents and to AgNO3 at concentrations that allowed 75% cell survival after 72 h. To investigate algal response, silver accumulation, ROS content, damage to biomolecules (lipids, proteins, and DNA), activity of antioxidant enzymes (APX, PPX, CAT, SOD), content of non-enzymatic antioxidants (proline and GSH), and changes in ultrastructure were analyzed. The results showed that all treatments induced oxidative stress and adversely affected algal cells. AgNO3 resulted in the fastest death of algae compared to both AgNPs, but the extent of oxidative damage and antioxidant enzymatic defense was similar to AgNP-citrate. Furthermore, AgNP-CTAB showed the least toxic effect and caused the least oxidative damage. These results highlight the importance of surface-stabilizing agents in determining the phytotoxicity of AgNPs and the underlying mechanisms affecting aquatic organisms.

A review article, containing information on the options, possibilities, and prospects for the development of antibacterial finishing of textile materials, is presented. A wide range of products designed to impart antibacterial, antimicrobial, and antiviral properties to textile materials is considered. The main factors determining the appropriate decision on the technological and functional choice of the protective composition are presented, including the nature of the fiber-forming polymer, the tasks that the resulting material is designed to solve, and its application options. Compositions providing the required effect of destruction of the pathogenic flora and their application technologies are described. Special attention is paid to antimicrobial agents based on silver nanoparticles. Nanoparticles of this metal have a detrimental effect on antibiotic-resistant strains of bacteria; their effectiveness is higher as compared to a number of well-known antibiotics, for example, penicillin and its analogues. Silver nanoparticles are harmless to the human body. Acting as an inhibitor, they limit the activity of the enzyme responsible for oxygen consumption by single-cell bacteria, viruses, and fungi. In this case, silver ions bind to the outer and inner proteins of the bacterial cell membranes, blocking cellular respiration and reproduction. Various options to apply microencapsulation methods for the implementation of antibacterial finishing are considered, including: phase separation, suspension crosslinking, simple and complex coacervation, spray drying, crystallization from the melt, evaporation of the solvent, co-extrusion, layering, fluidized bed spraying, deposition, emulsion and interphase polymerization, layer-by-layer electrostatic self-assembly etc. All presented technologies are at various development stages-from the laboratory stage to production tests, they all have certain advantages and disadvantages. The accelerated development and implementation of the described methods in production of textile materials is relevant and is related to the existing complex epidemiological situation in the world.

Luminescent carbon dots (CDs) have become attractive materials because of their superior photophysical properties and various potential applications. However, most of the formerly developed CDs only have strong blue emission, which limits their further applications, particularly in bioimaging. Herein luminescent CDs have been successfully synthesized via a one-pot solvothermal process using 4-bromoaniline and ethylenediamine as starting materials. The luminescent CDs emit strong green fluorescence with high quantum yield as well as excellent biocompatibility and biolabeling potentials. At first, the luminescent CDs exhibited high selectivity for phosgene with a turn-off fluorescence detection. The limit of detection was 81 nM, which is sensitive for the determination of phosgene over other competing toxic pollutants. In addition, the luminescent CDs have shown a three-state \"on-off-on\" emission with the stepwise addition of Ag+ and cysteine (Cys). Luminescent CDs show fluorescence quenching by Ag+ and fluorescence regaining with further addition of Cys, with lower detection limits of 3.9 μM (Ag+) and 3.4 μM (Cys), respectively. The luminescent CDs were utilized to obtain a clear fingerprint. During the drying process, the coffee ring effect and electrostatic interaction between the positive surface charge of amine-functionalized CDs and negatively charged fingerprint residues facilitate the formation of clear fingerprints on different platforms.