Search

The removal of pollutants from water bodies is crucial for the well-being of humanity and is a topic of global research. Researchers have turned their attention to green synthesized nanoparticles for wastewater treatment due to their eco-friendly nature, biocompatibility, and cost-effectiveness. This work demonstrates the efficient removal of organic dye and both gram-positive and gram-negative bacteria from water bodies using copper-doped cerium oxide nanoparticles synthesized with Murraya Koenigii extract. Characterized via various methods, the 15% copper doped cerium oxide nanoparticles (Cu 15% NPs) exhibited maximum Congo red dye adsorption (98% degradation in 35 min). Kinetic analysis favoured a pseudo-second-order model, indicating the chemical nature of adsorption. Equilibrium adsorption isotherms aligned with the Langmuir model, indicating homogenous monolayer dye adsorption on the doped adsorbent. The maximum uptake of adsorbate, Q m obtained from Langmuir model for Cu 15% NPs was 193 mg g−1. The study also showed enhanced antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa for Cu-doped ceria, attributed to generation of reactive oxygen species (ROS) induced by the redox cycling between Ce3+ and Ce4+. This substantiated that the green synthesized copper doped cerium oxide nanoparticles are potential candidates for adsorptive removal of Congo red dye and as antibacterial agents. [ABSTRACT FROM AUTHOR]

The fruit extract of Buchanania obovata and the eutectic-based ionic liquid were utilized, in an eco-friendly, inexpensive, simple method, for synthesizing zinc oxide nanoparticles (ZnO NPs). The influence of the reducing, capping and stabilizing agents, in both mediums, on the structure, optical, and morphological properties of ZnO NPs was extensively investigated. The surface plasmon resonance peaks were observed at 340 nm and 320 nm for the fruit-based and the eutectic-based ionic liquid mediums, respectively, indicating the formation of ZnO NPs. XRD results confirmed the wurtzite structure of the ZnO NPs, exhibiting hexagonal phases in the diffraction patterns. The SEM and TEM images display that the biosynthesized ZnO NPs exhibit crystalline and hexagonal shape, with an average size of 40 nm for the fruit-based and 25 nm for the eutectic-based ionic liquid. The Brunauer–Emmett–Teller (BET) surface area analysis, revealed a value ∼13 m2 g−1 for ZnO NPs synthesized using the fruit extract and ∼29 m2 g−1 for those synthesized using the eutectic-based ionic liquid. The antibacterial activity of the biosynthesized ZnO NPs was assessed against clinically isolated Gram-negative (E. coli) and Gram-positive (S. aureus) bacterial strains using the inhibition zone method. The ZnO NPs produced from the eutectic-based ionic liquids confirmed superior antibacterial activity against both S. aureus and E. coli compared to those mediated by the utilized fruit extract. At a concentration of 1000, the eutectic-based ionic liquid mediated ZnO NPs displayed a maximum inhibition zone of 16 mm against S. aureus, while against E. coli, a maximum inhibition zone of 15 mm was observed using the fruit extract mediated ZnO NPs. The results of this study showed that the biosynthesized ZnO NPs can be utilized as an efficient substitute to the frequently used chemical drugs and covering drug resistance matters resulted from continual usage of chemical drugs by users. [ABSTRACT FROM AUTHOR]

Recently, cesium lead halide perovskites such as CsPb 2 Br 5 and CsPbBr 3 have drawn the attention of researchers because of their unique optical, electronic, and chemical properties. To improve the photo and/or chemical performance of such CsPb 2 Br 5 (termed as CPB hereafter), we have realized multiple facile routes for its combination with UV-active TiO 2 nanoparticles. Resultantly developed binary nanocomposites of TiO 2 , CPB perovskites and TiO 2 /CPB-nanocomposite (TiO 2 /CPB-NC) offered a meaningful photochemical contrast between pseudo-successive ionic layer adsorption and reaction (p -SILAR) and electrostatic self-assembly methods for targeting photocatalytic degradation of toxic dyes under solar irradiation and resulted significant performance as reactant for oxygen evolution (OER) as revealed by extensive electrochemical impedance spectroscopy (EIS). In parallel to extensive material-based characterization using SEM, XRD, and UV Vis. etc, the study was further extended to the theoretical investigation of the structure of CsPb 2 Br 5 , and antibacterial activity against gram-positive and gram-negative bacteria namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). RhB degradation of TiO 2 increased from 13% to 58% by deposition of CPB, in parallel to 100% inhition zone growth. [Display omitted] [ABSTRACT FROM AUTHOR]

The purpose of this work is to fabricate the advanced organic antibacterial coating containing the strong photocatalytic nanomaterials. For this purpose, firstly the TiO2–Ag hybrid nanoparticles are synthesized by chemical reduction method. Then, the antibacterial coating based on acrylic polyol, polyisocyanate, and these TiO2–Ag hybrid nanoparticles has been prepared. Mechanical properties show that the optimal content of TiO2–Ag hybrid nanoparticles in the coating matrix is 2 wt%, with its abrasion resistance of 166.2 L/mil; impact strength of 195 kg cm; adhesion of size #1 and relative hardness of 0.78. In addition, FE-SEM analysis shows that the nanocomposite coating has a tight structure with homogeneous dispersion of TiO2–Ag nanoparticles in the polymer matrix. The paint film has good antibacterial activity and has great application prospects. Data from the antibacterial test indicates that in the presence of an acrylic polyurethane coating containing 2 wt% TiO2–Ag, the number of viable Escherichia coli decreased from 3.4 × 105 CFU/ml to 1.5 × 102 CFU/ml after 24 h of culture. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and characterization of a copper-based layered double hydroxide (Cu-LDH) composite via the coprecipitation method. The composite material aimed to effectively remove the anionic dye "Coomassie Brilliant Blue" (CBB) and exhibit antibacterial properties against both gram-positive and gram-negative bacteria. The synthesized nanocomposites were characterized using various techniques. The adsorption of CBB dye was investigated by studying various physicochemical variables, including contact time, pH of the dye solution, and initial dye concentration. The optimal dosage and contact time for efficient CBB dye removal were determined as 0.07 g and 10 min, respectively. The results showed that Cu-LDHs exhibited a high adsorption capacity for CBB dye, with a maximum removal efficiency of 85% which could be achieved within 10 min, and the Cu-LDHs improved an experimental adsorption capacity at equilibrium qmax = 80 mg/g. The adsorption process followed a pseudo-second-order kinetic model. The Langmuir isotherm model provided a good fit to the equilibrium data, indicating monolayer adsorption. Furthermore, the antibacterial activity of Cu-LDHs was assessed against various bacterial strains using a diffusion method. The results demonstrated the inhibitory effects of Cu-LDHs and CBB-Cu-LDHs on bacterial growth at a dosage of 10 mg, indicating the potential of Cu-LDHs as antibacterial agents. The underlying mechanisms responsible for dye adsorption and antibacterial activity were discussed. [ABSTRACT FROM AUTHOR]

The young and old leaves of bitter orange (Citrus aurantium) were examined for their essential oil (EO) compositions, anticancer, antimicrobial, and antiviral activities. The EO yields were 0.77% in young leaves and 0.26% in old leaves. The EO composition showed the predominance of sabinene (37.17%), E-β-ocimene (8.21%), δ-3-carene (7.71%), linalool (7.35%), and limonene (5.43%) in young leaves while of sabinene (47.47%), β-sinensal (5.71%), E-β-ocimene (4.98%), δ-3-carene (4.11%), and β-caryophyllene (4.06%) in old leaves. The EOs of both young and old leaves showed potent cytotoxic activities against human lung carcinoma (A549) and colon adenocarcinoma (DLD-1) cells with IC50 < 0.1 µg/mL. The young leaf EO had higher antibacterial activity than the old leaf EO for all bacterial strains with inhibition zones (IZ) varying from 17 to 45 and 8 to 36 mm, respectively. The EOs of both young and old leaves had strong antifungal activity against all fungal strains with IZ = 90 mm. The young leaf EO was found to be the most active in protecting cells against Herpes simplex virus type-1 (HSV-1) infection during the protection, absorption, and direct periods as compared to the untreated and treated Vero cells except the replication phase. [ABSTRACT FROM AUTHOR]

Wild grapevines are a rich source of polyphenolic compounds. Various environmental factors can influence these bioactive metabolites, contributing to stress mitigation and adaptation. The present study aimed to investigate the impact of prolonged drought stress on the accumulation of phytochemicals, antioxidants, and antimicrobial activity in the roots of the endangered Tunisian wild grapevine (Vitis vinifera subsp. sylvestris) "Tebaba" genotype. The results revealed that under prolonged drought stress, there was a significant increase in total phenolic compounds, total flavonoid content, and stilbenes, which showed a positive and significant correlation with the total antioxidant activity. Furthermore, the ethanolic extracts demonstrated an enhanced in vitro antibacterial effect against selected human pathogenic bacterial strains, including Staphylococcus aureus, Methicillin-resistant S. aureus, and Enterococcus faecalis. The minimum inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) values, relative to prolonged drought stress, ranged from 125 to 250 µg/mL. The values of the ratio between MBC and the MIC showed that the activity of the root extract was bactericidal in all cases (MBC/MIC ≤ 2). This study highlights the potential of wild grapevine roots enriched with drought-inducible phenolic compounds, as a promising source of antimicrobial agents relevant to human health applications. [ABSTRACT FROM AUTHOR]

In the current study, pulsed laser ablation in a liquid process was used to create gold nanoparticles (Au NPs) in the deionized distilled water. The pulsed laser ablation in liquid (PLAL) technique was used to create the NPs in two different processes. In first method, the Au nanoparticles were prepared with different laser fluences (2.2, 4.4, 6.64, 8.85, and 11.1) J.cm−2, and the number of pulses was fixed at 300 pulses for each fluence. The second method uses different number of laser pulses (100, 200, 300, 400, and 500) while maintaining a consistent laser fluence (4.4 J.cm−2). The characterization of nanoparticles was investigated using different techniques like UV-VIS, FTIR, XRD analysis, FE-SEM, and PL spectra. The UV-visible absorbed spectrum of Au nanoparticles revealed an absorption peak at about 530 nm and another peak at about 433 nm. The FTIR measurements have successfully shown that the entire (Au NPs), which are being generated. The X-ray diffraction pattern of the nanoparticles indicated the presence of Au nanomaterials and 111, 200, and 311 planes that correspond to Au NPs. The images of FE-SEM show that the Au NPs exhibited a spherical shape framework, agglomeration, and aggregation. With increasing laser fluence, the highest level of fluorescence emission was seen at 380 and 370 nm for Au NPs. The antibacterial activities of Au NPs were investigated using well diffusion method. Two gram-positive and two gram-negative bacteria of four different species have each been exposed to antibiotic activity. Au NPs have revealed a higher activity against tested bacteria. The results revealed that the 1250 µg/mL has high activity against Pseudomonas aeruginosa and Staphylococcus aureus, while Streptococcus mutans has been affected by all concentrations of Au NPs, and Acinetobacter baumannii has been highly affected by 1000 µg/mL and 1250 µg/mL. [ABSTRACT FROM AUTHOR]

CuS nanostructures with high surface areas were produced through a hydrothermal method using simple materials. These included pure CuS, as well as CuS doped with Fe, Ag, and Mn, as well as dual-doped with Fe/Mn and Ag/Mn. X-ray diffraction (XRD), field-emission scanning electron microscopes (FE-SEM), chemical composition (EDX) analysis, zeta potential, ultraviolet–visible (UV–vis) absorption spectra, and compositional chemicals (FTIR) have been used to characterize the produced nanoparticles. The XRD patterns indicate that the CuS is in hexagonal covellite polycrystalline phases with estimated crystalline sizes of 25.14–14.25 nm. The optical measurements showed that the band gaps ranged from 3.19 to 2.24 eV. The inhibitory effects of pristine CuS, as well as CuS doping with Fe, Ag, and Mn and dual-doping with (Fe/Mn, Ag/Mn), against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, were evaluated using the inhibition zone method. All samples exhibited robust antibacterial activity against all strains. The highest level of inhibition against all strains was observed with a concentration of 4 mg/ml of copper sulfide. Out of all the tested samples, (Ag/Mn) dual-doped copper sulfide showed the highest antibacterial activity against both negative-gram and positive-gram bacteria. Hence, (Ag/Mn) dual-doped copper sulfide might be applied as an antibacterial agent with antibiotics to kill and prevent resistance bacterial development. [ABSTRACT FROM AUTHOR]

Petroleum-based plastics have been widely used as packaging materials because of their low-cost availability and good mechanical properties. However, the use of plastics has become restricted as they are highly resistant to biodegradation, causing environmental problems. This work aimed to produce and characterize emulsified pullulan films incorporating geraniol for application as food packaging materials with potential to substitute the conventional plastics. When geraniol was incorporated in the films, they showed antimicrobial activity against Enterococcus faecalis ATCC 29212 (inhibition zone diameter = 15.19 ± 0.66 mm) and Pseudomonas aeruginosa ATCC 27853 (inhibition zone diameter = 10.99 ± 1.82 mm). Furthermore, scanning electron microscopy showed the inhibition of Enterococcus faecalis ATCC 29212 biofilms when they were directly formed on the emulsified pullulan films incorporating geraniol. The produced films also demonstrated high transparency (> 90%) and hydrophilic surfaces (water contact angle < 90°). This work demonstrated the viability of using geraniol to produce pullulan active films as new food packaging materials. [ABSTRACT FROM AUTHOR]

This study proposed an innovative approach to the development of sustainable and biodegradable food packaging materials by incorporating inexpensive nano-silica (SiO2NPs) in designed hydrogel (CSG) film employing biodegradable polymers: synthetic polymer polyvinyl alcohol (PVA), natural polymer - carboxymethyl cellulose (CMC) and protein-based bio-polymer –gelatine, and a commercial crosslinker, tetraethoxysilane (TEOS) through a conventional air-dry casting technique. The CSG hydrogel blends were modified with varying amounts of SiO2NPs (0.05g, 0.1g, 0.15g and 0.2g) and compared with the blend without SiO2NPs to determine the effect of SiO2NPs loading through various characterisation techniques and applications including antioxidant and antimicrobial activity. Comprehensive characterizations of the CSG films revealed that CSG 0.1 (containing 0.1g SiO2NPs) exhibited the most favourable functional properties, low crystallinity, high flexibility, suitable pore size, thermal stability, adequate tensile strength, elongation at the breaking point and maximum stability by swelling and diffusion test. The addition of SiO2NPs consistently enhanced thermal and mechanical stability in all CSG films. Further, these CSG films were implemented for antioxidant test and antimicrobial activity against gram-positive Bacillus cereus and gram-negative Escherichia coli. SiO2NPs integration significantly elevated the antioxidant capacity in all films, with CSG 0.1 showing ⁓7% improvement. The antimicrobial activity of SiO2NPs-modified CSG films was also notable, with CSG 0.1 effectively inhibiting B. cereus by 1.2cm zone and E. coli by 0.5cm zone. A soil burial test was performed to pattern the biodegradability of CSG hydrogels. Therefore, the outstanding improvements in the intrinsic properties of CSG films, owing to SiO2NPs modification, positioned these CSG hydrogels as promising candidates for advanced food packaging materials in various industries. [ABSTRACT FROM AUTHOR]

With the increasing concern for health and safety, it is crucial to investigate how antibacterial agents demonstrate high antibacterial activity in two-phase blend systems. In this study, we prepared antibacterial films comprising a low concentration (0.2%) zinc oxide/ethylene-octene copolymer (ZnO/POE) and ZnO/linear low-density polyethylene (LLDPE) with high antibacterial activity (99.9%) and an antibacterial property value (R) of 6.9. The addition of nanometer (nano) ZnO induces the crystallization of pure materials, increasing their crystallinity and long period and significantly reducing spherulite size. Using a two-phase blending process, we achieved an antibacterial activity of (ZnO/POE)/(ZnO/LLDPE) (0.2%) of 99.9% with an R-value of 6.9, superior to the single-phase blending of POE/(ZnO/LLDPE) (0.2%) (99.0%, R = 2.0). Significantly, this difference can be attributed to the fact that nano-ZnO promotes the compatibility of POE and LLDPE in the two-phase blending process. Additionally, the two-phase blending process enhances tear strength and light transmittance compared to single-phase blending. These findings are of great significance for developing nano-ZnO-based two-phase blend antibacterial materials with low concentration and high antibacterial activity. [ABSTRACT FROM AUTHOR]

This research aimed to prepare wheat gluten-based films activated by free and encapsulated L. majorana Origanum essential oil (MEO). Tween 80 and whey protein isolate were utilized to prepare MEO-loaded nanoemulsion (NE) and Pickering emulsion (PE), respectively. PE and NE had particle sizes of 186.7 nm and 149.5 nm, respectively. The NE had lower zeta potential and higher encapsulation efficiency. After incorporation of the obtained nanocapsules and free MEO into the gluten films at three levels (1, 3 and 5 wt%), the morphological, physical, antioxidant and antibacterial characteristics of the active films were assessed. According to the FE-SEM analysis, the surface roughness of films increased by adding free MEO and nanocapsules. XRD test revealed that the free MEO causes a decrease in the crystallinity of the film, but its encapsulated forms had no adverse effect. Improving the thermal properties of gluten films after the incorporation of PE-MEO nanocarriers was approved by TGA analysis. Adding free and encapsulated MEO led to an increase in the water solubility of films and a decrease in the WVP. The weakening effect of MEO on the mechanical characteristics of gluten films was the lowest when the PE nanocapsules were incorporated. The antioxidant activity of the films increased significantly (p < 0.05) with the addition of free and encapsulated MEO. However, the encapsulation slightly decreased the antibacterial potential of MEO against E. coli and S. aureus. To conclude, the produced active gluten film with encapsulated MEO, especially the PE one, presented considerable potential for use as active food packaging. [ABSTRACT FROM AUTHOR]

Black textile filaments having good mechanical strength and low water absorbency were spun from carboxymethylated cellulose cross-linked with amine functionalized carboxylated carbon nanotubes (afc-CNT). Incorporating 1 wt.% afc-CNT by crosslinking resulted in filaments with increased mechanical strength (tenacity ~ 1.2 cN/dtex) and a lower water absorbency (water absorbency ~ 0.62 g water/g fiber). The fabricated cellulosic textile filaments also demonstrated antibacterial activity and UV protection capability due to incorporation of afc-CNT. Excellent level of color fastness was achieved for the composite textile filaments because of a chemical bond formation between carboxymethylated cellulose and afc-CNT. [ABSTRACT FROM AUTHOR]

Double epoxy group double quaternary ammonium salts (DEpDQAS) were synthesized by epichlorohydrin (ECH) reacting with N,N,N'N'-tetramethylethylenediamine (TMEDA) and N,N,N'N'-tetramethyl-1,6-hexanediamine (TMHDA), respectively. The results of orthogonal experiments showed that temperature and time were the key factors influencing on epoxy value and quaternarization ratio respectively. The optimal condition for higher epoxy value was the reaction temperature at 15 °C and methanol as solvent. The reaction kinetic process was determined by conductivity, which showed that the reaction had a short induction period and appeared discontinuity in progress that the reaction rate of the first stage was almost constant, while the reaction rate of the second stage decreased gradually. The product was characterized by infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H NMR). The results of surface tension testing showed that DEpDQAS-6 with longer spacer chain had better surface activity and lowered the solution surface tension to 26 mN·m−1 at 25 °C and CMC 0.27 mol·L−1. The thermodynamic parameters of micellization were obtained basing on charged pseudo-phase model. The studies of cytotoxicity in vitro and antibacterial activity showed that DEpDQAS was biocompatible and its antibacterial activity was more effective against Escherichia coli than against Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Vibrio harveyi and Vibrio parahaemolyticus are species of the Vibrio genus that often cause disease and mass mortality in crustaceans. If not handled quickly and appropriately, these diseases can cause considerable losses to farmers. Therefore, it is necessary to find a solution with safe and environmentally friendly disease prevention technology using natural ingredients, among others from plants, namely oil palm. Some parts of oil palm, namely leaves, fronds, fibres and oil palm pulp, which are palm waste, contain antibacterial compounds. This study aimed to assess the antibacterial activity of palm waste extracts, namely pulp, leaves, fronds and fibres using n‐hexane, ethyl acetate, chloroform, ethanol and water maceration solvents against pathogenic bacteria V. harveyi and V. parahaemolyticus, and identify active compounds contained in palm waste. The results of the research are expected to produce innovative and sustainable solutions to control diseases in shrimp farming, contribute to the development of a sustainable fishing industry and open up the potential for utilizing palm waste as a value‐added resource in the field of aquatic health. The results of observations on antibacterial activity tests and identifying the content of palm waste extract compounds were analysed descriptively displayed in the form of figures, tables and graphs. The results showed that palm waste extracts (pulp, leaves, fronds and fibres) with ethyl acetate and ethanol maceration solvents had very strong antibacterial potential, namely 20.14 ± 0.31 mm–25.52 ± 1.42 mm on V. harveyi bacteria and 20.41 ± 0.55 mm–25.00 ± 0.51 mm on V. parahaemolyticus bacteria. Palm extracts with n‐hexane (>20 mm) and chloroform solvents generally have strong category antibacterial potential (10–20 mm), and palm extracts in water solvents have medium category potential (5–10 mm) against V. harveyi and V. parahemolyticus bacteria. The results of phytochemical tests on palm waste extracts with ethyl acetate and ethanol maceration solvents contain bioactive compounds of flavonoids, saponins, polyphenols and alkaloid tannins, steroids and triterpenoids. Palm extracts with n‐hexane and chloroform solvents generally contain saponins, alkaloids, steroids and triterpenoids, while palm waste extracts with water solvents contain saponins. [ABSTRACT FROM AUTHOR]

Diabetics are susceptible to severe trophic problems and wounds, which are frequently referred to as "unhealable wounds". Untreated diabetic wounds provide an ideal habitat for the growth of bacteria, which can eventually develop resistance to standard treatments and need amputation. This study aimed to assess the in vitro antibacterial activity of ethanolic and aqueous extracts of Eriosema robustum leaves on the same bacterium, as well as the resistance profile of bacteria isolated from diabetic wounds to conventional antibiotics. Thirty samples from diabetic wounds were collected at the Baleveng Hospital, subjected to bacteria isolation and antibiotics resistance tests using the disk diffusion method. On the other hands, leaves of Eriosema robustum were collected, hydroethanolic extraction were performed. The extract obtained was used for the antibacterial (by determination of the MIC) and antioxidant (DPPH and FRAP tests) activities as well as phytochemicals composition (using HPLC methods) assessment. Amon the 30 samples analyzed, 19 (63.33 %) showed bacterial infections and Staphylococcus aureus was the most common pathogen (48 %), followed by Pseudomonas aeruginosa (24 %), Klebsiella pneumoniae (19 %), and Streptococcus agalactiae (9 %). Fifty percent (50 %) of S. aureus isolates were MRSA (methicillin-resistant S. aureus). The MIC value obtained 64 µg/mL against S. aureus, Streptococcus agalactiae and Pseudomonas aeruginosa. Phytochemicals analysis of fractions from the 70 ° hydroethanolic leaves of Eriosema robustum revealed the presence of coumarin, gallic acid, quinoline, vanillin, ascorbic acid, caffeic acid, kaempferol, and cinnamic acid. The antibacterial and antioxidant potential of the extracts highlighted in this study could make this plant a good avenue for the discovery of new molecules effective against infected diabetic wounds. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the antimicrobial effectiveness of cinnamaldehyde (CIN) and potassium sorbate (P.S.), alone and in combination, against Salmonella Typhimurium and Staphylococcus aureus in vitro and in apple jam. Antimicrobial activity in vitro was investigated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), time-kill assay and determination of fractional inhibitory concentration index. CIN MIC and MBC was 312 μg/mL. P.S. MIC and MBC were 2500 and 5000 μg/mL, respectively, against S. Typhimurium; and 10,000 and 20,000 μg/mL, respectively, against S. aureus. The compounds combined exhibited a synergistic effect (FIC < 0.5), inhibiting S. Typhimurium growth after 12 h and S. aureus after 24 h. The effect of CIN and P.S., at sub-inhibitory concentrations, against bacterial strains in apple jam was evaluated during storage. Physicochemical and sensory analyses were also performed. No cultivable S. Typhimurium or S. aureus cells were recovered in apple jam supplemented with CIN + P.S. on the third day of storage. The addition of CIN and P.S. did not affect the physicochemical properties and sensory evaluation showed a score above 7.0. CIN and P.S. association at sub-inhibitory concentrations was effective in controlling foodborne pathogens and improved the shelf life of apple jam. [ABSTRACT FROM AUTHOR]

This study was conducted to determine whether the macroalgae Ulva papenfussi and Ulva nematoidea could be alternatives for preventing Litopenaeus vannamei vibriosis caused by the bacterium Vibrio parahaemolyticus. Phytochemical screening was performed on methanolic extracts to qualitatively determine the main groups of bioactive compounds, previous to an in vitro antibacterial test against V. parahaemolitycus. Phenols, polyphenols, flavonoids, and the high presence of carbohydrates were found in both macroalgae. U. papenfussi showed more presence of lipids and alkaloids than U. nematoidea. Macroalgae extracts prepared (v:v) with a 1:1 methanol: dichloromethane solvent was used for the in vitro test using the disc diffusion method (MDD). Filter paper discs impregnated with 1.0, 1.5, 2.0, 3.0, and 4.0 mg of the extracts showed antibacterial activity against V. Parahaemolitycus in a dose-dependent manner in both macroalgae. The inhibition zone varied significantly (p < 0.05) from 8.33 ± 0.12 to 11.41 ± 0.73 mm for 1 to 3 mg of extract levels, respectively. In conclusion, both macroalgae have antibacterial activity in their crude extracts against this bacteria. It is suggested to evaluate it as a feed additive for L. vannamei. This study is the first report on a phytochemical screening and antibacterial activity of these macroalgae against V. parahaemolyticus. [ABSTRACT FROM AUTHOR]

The antibacterial effect of nanoparticles is mainly studied on the ensembles of the bacteria. In contrast, the optical tweezer technique allows the investigation of similar effects on individual bacterium. E. coli is a self-propelled micro-swimmer and ATP-driven active microorganism. In this work, an optical tweezer is employed to examine the mechanical properties of E. coli incubated with ZnO and Ag nanoparticles (NP) in the growth medium. ZnO and Ag NP with a concentration of 10 µg/ml were dispersed in growth medium during active log-growth phase of E. coli. This E. coli-NP incubation is further continued for 12 h. The E. coli after incubation for 2 h, 6 h and 12 h were separately studied by the optical tweezer for their mechanical property. The IR laser (λ = 975 nm; power = 100 mW) was used for trapping the individual cells and estimated trapping force, trapping stiffness and corner frequency. The optical trapping force on E. coli incubated in nanoparticle suspension shows linear decreases with incubation time. This work brings the importance of optical trapping force measurement in probing the antibacterial stress due to nanoparticles on the individual bacterium. [ABSTRACT FROM AUTHOR]

Bacterial species referred to as magnetotactic bacteria (MTB) biomineralize iron oxides and iron sulphides inside the cell. Bacteria can arrange themselves passively along geomagnetic field lines with the aid of these iron components known as magnetosomes. In this study, magnetosome nanoparticles, which were obtained from the taxonomically identified MTB isolate Providencia sp. PRB-1, were characterized and their antibacterial activity was evaluated. An in vitro test showed that magnetosome nanoparticles significantly inhibited the growth of Staphylococcus sp., Pseudomonas aeruginosa, and Klebsiella pneumoniae. Magnetosomes were found to contain cuboidal iron crystals with an average size of 42 nm measured by particle size analysis and scanning electron microscope analysis. The energy dispersive X-ray examination revealed that Fe and O were present in the extracted magnetosomes. The extracted magnetosome nanoparticles displayed maximum absorption at 260 nm in the UV-Vis spectrum. The distinct magnetite peak in the Fourier transform infrared (FTIR) spectroscopy spectra was observed at 574.75 cm−1. More research is needed into the intriguing prospect of biogenic magnetosome nanoparticles for antibacterial applications. [ABSTRACT FROM AUTHOR]

The potential risk of bacteria‐induced prosthetic infection during implantation/post‐operative healing raises a serious concern about the success of implant/surgery. In this context, the present study successfully established the antibacterial efficacy of the electret form of Mg1‐xCaxSi1‐xZrxO3 (x = 0, 0.1, 0.2, 0.3, 0.4 [MCSZO‐X]) bioceramics, toward both, Escherichia Coli and Staphylococcus aureus bacteria with reference to those of hydroxyapatite (HAP). MCSZO‐X bioceramics were synthesized using a solid‐state route. The influence of Ca‐ and Zr co‐doping on the crystallite size of MCSZO‐X has been analyzed using X‐ray peak profile analyses. The electrets were developed by corona poling of sintered MCSZO‐X samples at voltage and temperature of 20 kV and 500°C (30 min), respectively. The charge, stored on the surface of MCSZO‐X electret samples was calculated to be 0.253, 0.294, 0.320, 0.173, and 0.161 µC/cm2 via thermally stimulated depolarized current measurement. The positive and negative ends of MCSZO‐ X electrets exhibited a reduction in the viability of E. coli bacteria by (24%, 25%, 30%, 43%, and 42%) and (29%, 37%, 39%, 51%, and 48%), respectively, in comparison to those of HAP. On the contrary, the viability of S. aureus bacteria has decreased by (26%, 33%, 35%, 46%, and 42%) and (21%, 22%, 27%, 395, and 37%) on the surfaces of the positive and negative ends of MCSZO‐ X electrets, respectively, with the reference of those of HAP. The mechanism of electret‐induced antibacterial activity has been revealed via various assays, such as catalase activity, superoxide production (SOD), , protein estimation, and lipid peroxidation (LPO) assays. The positive ends of MCSZO‐X electrets demonstrate antibacterial efficacy by means of more reactive oxygen species generation as compared to their negative ends of electrets and uncharged surfaces of MCSZO‐X samples, as revealed by SOD, protein estimation, catalase activity, and LPO assays. However, the negative ends of electrets prevent the adhesion of bacterial cells via electrostatic repulsion. [ABSTRACT FROM AUTHOR]

In the present study, copper oxide (CuO) nanoparticles were biosynthesized from an Aspergillus niger cell-free extract (CFE), and several optimal operating parameters that affected the formation and dimensions of the CuO nanoparticles were determined, as follows: 15 mmol/L metal salt and 90 mL of CFE at room temperature for 24 h, to achieve an average size of 77 nm. Spectroscopic studies revealed an association between alcohol, alkene, and amine functional groups and the grain-shaped CuO nanoparticles. The elemental composition of the nanoparticles was confirmed by energy dispersive X-ray spectroscopy (EDX) data. Mycogenic CuO nanoparticles exhibited excellent antibacterial activity against Gram-positive bacterial species compared with Gram-negative bacterial species, i.e., Streptococcus pneumoniae MTCC 2672, Staphylococcus aureus MTCC 737, Micrococcus luteus MTCC 11948, Pseudomonas aeruginosa MTCC 424, and Escherichia coli MTCC 443, at 200 mg/mL, with inhibition zones of 9.2, 8.3 7.7, 7.2, and 6.1 mm, respectively. Finally, myogenic CuO nanoparticles exhibited good antifungal activity against Aspergillus fumigatus and Aspergillus versicolor. [ABSTRACT FROM AUTHOR]

Pistacia lentiscus leaf extract has been used as a reducing and capping agent for the green production of zinc oxide nanoparticles (ZnO NPs) to evaluate their antioxidant and antibacterial properties. The optical and structural properties were determined by ultraviolet-visible (UV-Vis) spectra, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). In the UV-Vis spectra, an absorption peak at 310 nm was observed, whereas the FTIR spectra revealed a peak at 680 cm-1, attributed to the vibration of ZnO NPs and confirmed their formation. X-ray analysis showed the crystalline quality of the ZnO product, with well-defined peaks on the (002), (100), and (101) planes, confirming a hexagonal structure (JCPDS-file: 36-1451). The grain size of the ZnO NPs was approximately 33.90 nm in diameter. Using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (EDS), the morphology of the nanoparticles resembled dried cotton, whereas EDS confirmed the presence of zinc (Zn) and oxygen (O). The evaluation of antioxidant activity involved the DPPH test, thin-layer chromatography (TLC) bioautography, and spectrophotometric assay. The methanolic extract exhibited high antiradical potential, followed by aqueous, etheric, and finally ZnO NPs. Testing the antibacterial activity against two Gram-positive bacterial strains (Staphylococcus aureus and Bacillus cereus) and two Gram-negative strains (Escherichia coli and Pseudomonas aeruginosa) involved determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The results showed that zinc oxide nanoparticles displayed considerable antibacterial effects compared with crude extracts, demonstrating inhibition zones of (24 ± 1) mm and (20 ± 2) mm, respectively, against E. coli and P. aeruginosa, with a bactericidal effect evident by a MBC/MIC ratio of 2. [ABSTRACT FROM AUTHOR]

\nPractical ApplicationsThis work aimed to evaluate the effect of different extraction solvents on the polyphenolic content, antioxidant and antibacterial activity of Pistacia lentiscus stems. The results obtained show that the extraction yield depends strongly on the polarity of the solvent and the extraction method. The ethanolic extract had the highest yield in both extraction methods investigated, namely Soxhlet (R = 9.89%) and cold maceration (R = 9.20%). The free radical scavenging activity of the extracts showed that the ethanolic extract had the highest antioxidant activity in both extraction methods with an IC50 = 0.023 mg/mL (cold maceration) and an IC50 = 0.034 mg/ml (Soxhlet). The HPLC analysis of the extracts indicates that gallic acid and catechin are the major phenolic compounds. The FTIR results showed that the shift of the stretching is responsible for O-H and C-H bonding. The GC-MS analysis revealed the presence of stearic acid and palmitic acid methyl ester as main compounds. The bacterial analysis of the extracts showed that the aqueous extract represents the most active one against Staphylococcus aureus and Pseudomonas aeruginosa; on the other hand, no antifungal activity was appreciated. Overall, the results indicate that the investigated extracts might be considered valuable sources of bioactive compounds.The study provides an overview of the yield, phenolic composition, and biological activities of Pistacia lentiscus stems. No information is available on research conducted to compare extraction techniques and solvent effects on the recovery of phenolic components, flavonoids, and antioxidant activity; only one paper has reported so far the phenolic characterization of Pistacia lentiscus stems. The data can be useful for future in vivo studies to support their antioxidant and antimicrobial properties. In addition, the sample preparation technique used in this study can provide a basis for the extraction of similar phenolic compounds in other parts of the plant. [ABSTRACT FROM AUTHOR]

This work aims to fabricate the antibacterial coating with green biocide successfully. For this purpose, mimosa tannins were acylated with lauroyl chloride’s aid and pyridine’s support as a catalyst in the 1,4-dioxane, hexane and xylene solvents. Infrared analysis showed that mimosa tannins synthesized in the 1,4-dioxane were acylated better than in the other two solvents. FE-SEM analysis of the paint film showed that the acylated mimosa tannins at a content of 5 % dispersed quite well in the polymer matrix. The results of analyzing the mechanical properties of the paint film containing acylated mimosa tannins with contents ≤5 % show that the mechanical properties of the paint film are only slightly reduced compared to the mechanical properties of the pure coating, reaching the values: adhesion of size #1; abrasion resistance of 132.8 L/mil; impact strength of 170 kg cm and a relative hardness of 0.78. Antibacterial testing shows that the paint film containing 5 wt% acylated mimosa tannins have good antibacterial activity. [ABSTRACT FROM AUTHOR]

From the perspective of possible antiviral and antibacterial activity of vanadium‐based complexes, we report the synthesis of new Schiff base ligand (L4) and a new Schiff‐base‐vanadium complex (C2). Both the ligand and the complex were characterized by Fourier transform infrared spectroscopy and Nuclear magnetic resonance techniques. Single‐crystal X‐ray Diffraction analysis has been used to confirm the structure of ligand L4 and complex C2. In addition, L1–4 and C1–3 were tested for their antibacterial effects against Escherichia coli and Staphylococcus aureus. Among the compounds, L2 demonstrated the most potent inhibition of both bacteria, exhibiting the lowest values for minimum inhibitory concentration (CMI) and minimum bactericidal concentration (CMB) (CMI = 0.16, CMB = 0.31 against E. coli, and CMI = CMB = 0.16 against S. aureus). Additionally, L2 produced the largest inhibition zones with diameters of 15.5 ± 0.15 against E. coli and 14.5 ± 0.04 against S. aureus. Furthermore, the antiviral efficacy of L1, L2, L4, C1, C2, and C3 against RNA viruses was assessed. C2 and C3 exhibited the most potent antiviral activity among the tested compounds. [ABSTRACT FROM AUTHOR]

AbstractThe green synthesis of metallic nanoparticles using plant extracts is attracting increasing attention as it is cost-effective, environmentally friendly, and suitable for large-scale production. Phytochemicals in plant extracts are used to reduce and stabilize metal nanoparticles. This study highlights the synthesis of silver nanoparticles (Ag NPs) at room temperature using Laurus nobilis (L. nobilis) leaf extract and their antibacterial and cytotoxic activities for biomedical applications. Ag nanoparticles (Ag NPs) were synthesized using L. nobilis leaf extract via the green approach. The synthesized Ag NPs were characterized by UV–Visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier transform infrared, and X-ray diffraction (XRD) analysis. According to TEM, SEM, and XRD diffraction analysis, it was found that the synthesized Ag NPs have a face-centered cubic crystal structure with a mean particle size of 13 ± 4 nm. The synthesized Ag NPs were tested for their in vitro antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The minimum inhibition concentration (MIC) and minimum bactericidal concentration values of Ag NPs were 3.5, 0.45, and 7, 0.9 μg/mL, respectively. The synthesized Ag NPs were screened toward the human liver cancer cell line in vitro. The results show that the Ag NPS synthesized using L. nobilis leaf had high cytotoxic activity with an IC50 value of 8.86 ± 0.74 µL/mL. [ABSTRACT FROM AUTHOR]

Herein, a borophene/zinc oxide (BZ) nanocomposite is synthesized through a straightforward one‐step solvothermal process, avoiding the need for any rigorous reducing agent. The BZ nanocomposites are introduced into semi‐interpenetrating polymer networks to form hydrogels via in situ UV triggered free radical gelation during three‐dimensional (3D) microextrusion printing. The hydrogels exhibit mechanical robustness, high compressibility, pH sensitivity, and microporosity. The diffusion behavior of the hydrogel shows a combination of swelling and molecular chain relaxation based on its water uptake kinetics. Hydrogels are tested in rigorous pH environments over multiple cycles to ensure structural integrity. The rheological assessment of the hydrogels proves their high elasticity. The uniaxial mechanical properties support its mechanical toughness and zero permanent set resulting elastomeric soft matrix. The cyclic compression test up to 100 cycles has negligible data deviations in calculating compression moduli (≈24 kPa). The hydrogels are non‐toxic and found to be effective bactericidal materials for both Gram‐positive and Gram‐negative bacteria. The hydrogel demonstrates pH‐responsive time‐dependent payload release behavior, suggesting its potential as a soft matrix drug carrier in biomedical research. To the best of the authors knowledge, this is the first report of BZ‐based soft biomaterial with antibacterial properties serving as an excellent controlled drug delivery device. [ABSTRACT FROM AUTHOR]

Organosulfur compounds derived from plants of the Allium genus, such as propyl‐propane‐thiosulfinate (PTS) and propyl‐propane‐thiosulfonate (PTSO), have been proposed as an alternative in antibiotic resistance. The aim of this study was to compare the activity of these substances with other antibiotics against clinical isolates of carbapenem‐resistant (CAR‐R) and carbapenem‐susceptible (CAR‐S) Gram‐negative bacteria. A total of 126 clinical isolates of CAR‐R and 155 CAR‐S bacteria were selected, including Enterobacterales, A. baumannii and P. aeruginosa. The antibiotic susceptibility of all isolates was assessed using the microdilution and Kirby–Bauer methods for PTS, PTSO, amoxicillin/clavulanate, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, ciprofloxacin, and amikacin. Both PTS and PTSO demonstrated in vitro bactericidal activity against CAR‐R Enterobacteriaceae and A. baumannii, with no significant difference in activity compared to their response against CAR‐S isolates. However, both compounds were less active against P. aeruginosa than against any of the other bacteria, regardless of their resistance to carbapenems. In all cases, the minimum inhibitory concentration values of PTSO were significantly lower than those of PTS. These findings offer valuable information about the potential antibacterial use of these substances, particularly against infections that currently have limited therapeutic options. [ABSTRACT FROM AUTHOR]

Bacterial infection is a common complication in bone defect surgery, in which infection by clinically resistant bacteria has been a challenge for the medical community. Given this emerging problem, the discovery of novel natural-type inhibitors of drug-resistant bacteria has become imperative. Brucine, present in the traditional Chinese herb Strychnine semen, is reported to exert analgesic and anti-inflammatory effects. Brucine's clinical application was limited because of its water solubility. We extracted high-purity BS by employing reflux extraction and crystallization, greatly improved its solubility, and evaluated its antimicrobial activity against E. coli and S. aureus. Importantly, we found that BS inhibited the drug-resistant strains significantly better than standard strains and achieved sterilization by disrupting the bacterial cell wall. Considering the safety concerns associated with the narrow therapeutic window of BS, a 3D BS-PLLA/PGA bone scaffold system was constructed with SLS technology and tested for its performance, bacteriostatic behaviors, and biocompatibility. The results have shown that the drug-loaded bone scaffolds had not only long-term, slow-controlled release with good cytocompatibility but also demonstrated significant antimicrobial activity in antimicrobial testing. The above results indicated that BS may be a potential drug candidate for the treatment of antibiotic-resistant bacterial infections and that scaffolds with enhanced antibacterial activity and mechanical properties may have potential applications in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Prediction of the antibacterial activity of new chemical compounds is an important task, due to the growing problem of bacterial drug resistance. Generalized linear models (GLMs) were created using 85 amidrazone derivatives based on the results of antimicrobial activity tests, determined as the minimum inhibitory concentration (MIC) against Gram-positive bacteria: Staphylococcus aureus, Enterococcus faecalis, Micrococcus luteus, Nocardia corallina, and Mycobacterium smegmatis. For the analysis of compounds characterized by experimentally measured MIC values, we included physicochemical properties (e.g., molecular weight, number of hydrogen donors and acceptors, topological polar surface area, compound percentages of carbon, nitrogen, and oxygen, melting points, and lipophilicity) as potential predictors. The presence of R1 and R2 substituents, as well as interactions between melting temperature and R1 or R2 substituents, were also considered. The set of potential predictors also included possible biological effects (e.g., antibacterial, antituberculotic) of tested compounds calculated with the PASS (Prediction of Activity Spectra for Substances) program. Using GLMs with least absolute shrinkage and selection (LASSO), least-angle regression, and stepwise selection, statistically significant models with the optimal value of the adjusted determination coefficient and of seven fit criteria were chosen, e.g., Akaike's information criterion. The most often selected variables were as follows: molecular weight, PASS_antieczematic, PASS_anti-inflam, squared melting temperature, PASS_antitumor, and experimental lipophilicity. Additionally, relevant to the bacterial strain, the interactions between melting temperature and R1 or R2 substituents were selected, indicating that the relationship between MIC and melting temperature depends on the type of R1 or R2 substituent. [ABSTRACT FROM AUTHOR]

Metal and metal oxide nanostructured materials have been chemically and physically characterized and tested concerning methylene blue (MB) photoremoval and UV antibacterial activity against Escherichia coli and Staphylococcus aureus. In detail, silver nanoparticles and commercial BaTiO3 nanoparticles were modified to obtain nanocomposites through sonicated sol–gel TiO2 synthesis and the photodeposition of Ag nanoparticles, respectively. The characterization results of pristine nanomaterials and synthetized photocatalysts revealed significant differences in specific surface area (SSA), the presence of impurities in commercial Ag nanoparticles, an anatase phase with brookite traces for TiO2-based nanomaterials, and a mixed cubic–tetragonal phase for BaTiO3. Silver nanoparticles exhibited superior antibacterial activity at different dosages; however, they were inactive in the photoremoval of the dye. The silver–TiOx nanocomposite demonstrated an activity in the UV photodegradation of MB and UV inhibition of bacterial growth. Specifically, TiO2/AgNP (30–50 nm) reduced growth by 487.5 and 1.1 × 103 times for Escherichia coli and Staphylococcus aureus, respectively, at a dose of 500 μg/mL under UV irradiation. [ABSTRACT FROM AUTHOR]

Hybrid nanomaterials have attracted considerable interest in biomedicine because of their fascinating characteristics and wide range of applications in targeted drug delivery, antibacterial activity, and cancer treatment. This study developed a gelatin-coated Titanium oxide/palladium (TiO2/Pd) hybrid nanomaterial to enhance the antibacterial and anticancer capabilities. Morphological and structural analyses were conducted to characterize the synthesized hybrid nanomaterial. The surface texture of the hybrid nanomaterials was examined by high-resolution transmission electron microscopy (HR-TEM) and field-emission scanning electron microscopy (FE-SEM). The FE-SEM image revealed the bulk of the spherically shaped particles and the aggregated tiny granules. Energy dispersive X-ray spectroscopy (EDS) revealed Ti, Pd, C, and O. X-ray diffraction (XRD) revealed the gelatin-coated TiO2/Pd to be in the anatase form. Fourier transform infrared spectroscopy examined the interactions among the gelatin-coated TiO2/Pd nanoparticles. The gelatin-coated TiO2/Pd nanomaterials exhibited high antibacterial activity against Escherichia coli (22 mm) and Bacillus subtilis (17 mm) compared to individual nanoparticles, confirming the synergistic effect. More importantly, the gelatin-coated TiO2/Pd hybrid nanomaterial exhibited remarkable cytotoxic effects on A549 lung cancer cells which shows a linear increase with the concentration of the nanomaterial. The hybrid nanomaterials displayed higher toxicity to cancer cells than the nanoparticles alone. Furthermore, the cytotoxic activity against human cancer cells was verified by the generation of reactive oxygen species and nuclear damage. Therefore, gelatin-coated TiO2/Pd nanomaterials have potential uses in treating cancer and bacterial infections. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is a natural polymer renowned for its unique physicochemical and mechanical attributes, including notable water-holding capacity, crystallinity, and a pristine fiber network structure. While BC has broad applications spanning agriculture, industry, and medicine, its industrial utilization is hindered by production costs and yield limitations. In this study, Rhizobium sp. was isolated from bean roots and systematically assessed for BC synthesis under optimal conditions, with a comparative analysis against BC produced by Komagataeibacter hansenii. The study revealed that Rhizobium sp. exhibited optimal BC synthesis when supplied with a 1.5% glucose carbon source and a 0.15% yeast extract nitrogen source. Under static conditions at 30 °C and pH 6.5, the most favorable conditions for growth and BC production (2.5 g/L) were identified. Modifications were introduced using nisin to enhance BC properties, and the resulting BC-nisin composites were comprehensively characterized through various techniques, including FE-SEM, FTIR, porosity, swelling, filtration, and antibacterial activity assessments. The results demonstrated that BC produced by Rhizobium sp. displayed properties comparable to K. hansenii-produced BC. Furthermore, the BC-nisin composites exhibited remarkable inhibitory activity against Escherichia coli and Pseudomonas aeruginosa. This study contributes valuable insights into BC’s production, modification, and characterization utilizing Rhizobium sp., highlighting the exceptional properties that render it efficacious across diverse applications. [ABSTRACT FROM AUTHOR]

This study developed a kind of PEG-crosslinked O-carboxymethyl chitosan (O-CMC–PEG) with various PEG content for food packaging. The crosslinking agent of isocyanate-terminated PEG was firstly synthesized by a simple condensation reaction between PEG and excess diisocyanate, then the crosslink between O-carboxymethyl chitosan (O-CMC) and crosslinking agent occurred under mild conditions to produce O-CMC–PEG with a crosslinked structure linked by urea bonds. FT-IR and 1H NMR techniques were utilized to confirm the chemical structures of the crosslinking agent and O-CMC–PEGs. Extensive research was conducted to investigate the impact of the PEG content (or crosslinking degree) on the physicochemical characteristics of the casted O-CMC–PEG films. The results illuminated that crosslinking and components compatibility could improve their tensile features and water vapor barrier performance, while high PEG content played the inverse effects due to the microphase separation between PEG and O-CMC segments. The in vitro degradation rate and water sensitivity primarily depended on the crosslinking degree in comparison with the PEG content. Furthermore, caused by the remaining –NH2 groups of O-CMC, the films demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus. When the PEG content was 6% (medium crosslinking degree), the prepared O-CMC–PEG−6% film possessed optimal tensile features, high water resistance, appropriate degradation rate, low water vapor transmission rate and fine broad-spectrum antibacterial capacity, manifesting a great potential for application in food packaging to extend the shelf life. [ABSTRACT FROM AUTHOR]

Sulfur polymers, prepared by inverse vulcanization using elemental sulfur and vinylic monomers, are emerging functional materials of current research interest; however, sulfur polymers suffer from limited water solubility due to the hydrophobic nature of conventional comonomers and sulfur. Herein, the preparation of ionic liquid (IL)‐containing sulfur polymers are reported using the hydrophilic ionic liquid, 1‐allyl‐3‐vinylimidazolium chloride (AVImCl) as a comonomer. The introduction of IL significantly enhances the hydrophilicity of sulfur polymers, enabling them to dissolve in water. Benefiting from the thorough contact with aqueous mercury ions, the resultant sulfur polymer possesses high uptake capacity (436 mg g−1). After binding mercury, a coordination complex is formed and precipitated. The charged sulfur polymers gain a new application in demulsification. The polymer quickly breaks oil‐in‐water (O/W) emulsions through anion exchange between Cl− of the polymer and dodecylbenzenesulfonate (DBS−) of the surfactant. In addition, the polymer has a growth inhibitory effect against Staphylococcus aureus. The integration of IL and elemental sulfur provides a novel approach to modifying the wettability of sulfur polymers. Also, this novel water‐soluble IL‐containing sulfur polymer, with mercury capture, demulsification, and antibacterial activity, can be considered as a multifunctional material in practical water purification. [ABSTRACT FROM AUTHOR]

AbstractHighly pure, crystalline and spherical-shaped Copper oxide nanoparticles (NPs) have been synthesized via facile chemical coprecipitation. Various models including the Scherrer, Monshi-Scherrer, Williamson-Hall, Size-Strain Plot and Halder-Wagner method have been applied to study the crystal structure characteristics. The lattice parameters associated with the monoclinic crystal lattice of CuO NPs were estimated to be a = 4.69 Å, b = 3.41 Å, c = 5.14 Å and β = 99.87(degree), unit cell volume V = 81.35Å3 and cell density dx = 6.49 g/cm3. The photocatalytic dye degradation proficiency at 20 mg/l CuO concentration and 120 min sunlight exposure results the order of percentage dye degradation Malachite Green (88.4%) > Crystal Violet (70.8%) > Eosin Yellow (70.2%) > Methylene Blue (54.08%) dyes. The antimicrobial activity assessment was done against the broad-spectrum pathogenic microbes unveiled the exceptional microbial controlling capability of CuO NPs. Furthermore, the antioxidant activity test demonstrated the potential free radical scavenging activity of CuO NPs with an IC50 value of 47.733 µg/ml. HighlightsSynthesis of pure and spherical shaped nanocrystalline CuO was done by using low cost and facile chemical coprecipitation method.XRD, FTIR, FESEM, EDX, UV-Vis, and Raman spectroscopic techniques were used for characterization purpose.The structural and crystallographic parameters of monoclinic crystal structure of CuO NPs were evaluated successfully.The photocatalytic performance of CuO NPs follow the percentage dye degradation order as MG (88.4%) > CV (70.8%) > EY (70.20%) > MB (54.08%) after 120 minutes of sunlight exposure.CuO NPs exhibit promising antifungal activity against COVID-19 associated Pulmonary Aspergillosis (CAPA) causing pathogenic fung.CuO NPs show potential DPPH free radical scavenging activity with an IC50 value of 47.733 µg/ml.Synthesis of pure and spherical shaped nanocrystalline CuO was done by using low cost and facile chemical coprecipitation method.XRD, FTIR, FESEM, EDX, UV-Vis, and Raman spectroscopic techniques were used for characterization purpose.The structural and crystallographic parameters of monoclinic crystal structure of CuO NPs were evaluated successfully.The photocatalytic performance of CuO NPs follow the percentage dye degradation order as MG (88.4%) > CV (70.8%) > EY (70.20%) > MB (54.08%) after 120 minutes of sunlight exposure.CuO NPs exhibit promising antifungal activity against COVID-19 associated Pulmonary Aspergillosis (CAPA) causing pathogenic fung.CuO NPs show potential DPPH free radical scavenging activity with an IC50 value of 47.733 µg/ml. [ABSTRACT FROM AUTHOR]

AbstractThe green synthesis of metal nanoparticles with curcumin which is a compound with antibiotic effects, was considered for the synthesis of metal nanoparticles. Gold and silver nanoparticles were synthesized with an average diameter of 19.8 ± 6.2 nm and 29.8 ± 6.4 nm respectively. Both particles represent stability in the physiological environment and after a series of washing procedures to remove unreacted precursors. The antimicrobial efficacy of the synthesized nanoparticles was investigated in different techniques such as disk diffusion, agar well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration tests. The results of both curcumin-coated metal nanoparticles in the disk diffusion test were negative. However, in the agar dilution and MIC tests of antibacterial effect of both nanoparticles on the tested bacteria was observed. The silver nanoparticles had an inhibitory effect on all selected bacteria in the agar dilution (8-256 µg/ml). However, gold nanoparticles had a lower inhibitory effect on the growth of some of the selected bacteria (64-512 µg/ml). In conclusion, silver nanoparticles were more effective than gold nanoparticles in most of the investigated methods. [ABSTRACT FROM AUTHOR]

TiO 2 photocatalyst was synthesised via a low-temperature sol-gel process using organic solvents (TO) and aqueous extract of mangrove leaves (TM) as media. The photocatalytic activities of the obtained TiO 2 nanoparticles (NPs) were evaluated by degrading reactive red 195 (RR195) dye under UV irradiation. An increase in the dosage of both TO and TM photocatalysts, coupled with a decrease in the initial concentration of RR195 dye, enhanced the dye degradation rate. Reactive species scavenger analysis revealed that •O 2 − radicals and electrons were the primary species involved in the photocatalytic degradation of RR195 dye. The antibacterial properties of both TO and TM NPs were also tested against S. aureus , E. faecalis and V. damsela bacteria using the disc diffusion method. The green method utilising TM demonstrated resistance to all three bacteria types, while TO exhibited greater resistance, specifically against V. damsela. Notably, TM NPs exhibiting inhibition comparable to Ciprofloxacin when used as a positive control. [ABSTRACT FROM AUTHOR]

Bromouracil derivatives are synthesized using an environmentally acceptable bromination protocol involving NaBr as a promoter. A minimum of 1.5 equivalent NaBr was required to reach the maximum yield. The reactions were conducted in an acidic medium in the presence of H2O2 under ambient conditions. We successfully synthesized ten novel 5‐bromouracil derivatives available in our laboratory and characterized them using various spectroscopic methods such as 1H‐NMR, 13C‐NMR, and SC‐XRD. All the derivatives are screened for anti‐bacterial activities against gram‐positive and gram‐negative bacteria. In particular, compounds 5‐bromo‐4‐chloro‐6‐methylpyrimidin‐2‐amine and 5‐bromo‐6‐chloropyrimidine‐2,4‐diamine exhibited prominent antibacterial activity against gram‐negative E. coli with IC50 values of ~9.8 and ~5.7 μg/mL. The structural‐activity relationship revealed that the presence of the −NH2 group in both the bromo derivatives affirms improving activity. Molecular docking studies also supported the experimental result and showed good binding energy of −4.4 (2 a) and −4.8 (2 b) kcal/mol against E. coli primase. [ABSTRACT FROM AUTHOR]

Treatment of isatin with ammonia in methanol under reflux, followed by hydrazine substitution of the methoxy group afforded isamic hydrazide in up to 79 % yield. Subsequent condensation of isamic hydrazide with selected aromatic ketones and aldehydes gave access to novel 2‐oxo‐1,2‐dihydro‐1′H‐spiro[indoline‐3,2′‐quinazoline]‐4′‐carbohydrazones (4–11) in yields between 59 % and 74 %. Detailed structural analysis of synthesized compounds was done using spectroscopic techniques. Antibacterial screening of the hydrazone derivatives (4–11) demonstrated broad‐spectrum activity against evaluated bacterial strains, with inhibition zones ranging from 10 to 32 mm. Specifically, compound 9 exhibited superior activity compared to the standard streptomycin against various bacterial strains, including B. polymyxa (LIO), B. cereus (NCBI 6349), C. pyogenes (LIO), B. subtilis (NCBI 3610), S. aureus (NCBI 8588), E. coli (NCIB 86), P. aeruginosa (NCIB 950), and K. pneumoniae (NCIB 418). Moreover, the inhibitory concentrations of compound 9 were lower than those of streptomycin, underscoring its efficacy as a potential antibacterial agent. These findings suggest that the synthesized hydrazone derivatives possess significant potential as novel and effective antibacterial agents, warranting further exploration in the field of antibacterial drug development. [ABSTRACT FROM AUTHOR]

In this study, we report the growth of surfactant‐free silver nanoparticles (NPs) on cotton through a facile chemical reduction method, iteratively applied to gradually increase and control the concentration of silver NPs. Our substrates showed enhanced performance in surface enhanced Raman spectroscopy (SERS), catalytic, and antibacterial properties, all attributable to the high concentration of NPs on the cotton and their surfactant‐free nature. While the antibacterial properties improve with increasing growth cycles, SERS and catalytic properties first increase from the first to fourth growth cycles and then decrease for the fifth growth cycle. For substrate with optimum deposition for SERS, rhodamine 6G (R6G) analyte down to nanomolar concentrations were detectable, with a linear correlation of intensity versus concentration and exhibit excellent uniformity in the SERS signal. Furthermore, the catalytic activity of our substrates against the degradation of methyl orange (MO) was impressive with a rate constant of 0.0866 min−1 for the first growth cycle, which increased by ~3.4‐fold to 0.2979 min−1 for the fourth growth cycle. Finally, the substrates showed excellent antibacterial activity towards both Gram‐negative (E. coli) and Gram‐positive (S. aureus) bacteria. For both bacteria, the zone of inhibition increased with increasing growth cycles. [ABSTRACT FROM AUTHOR]

The problem of antimicrobial resistance is becoming a daunting challenge for human society and healthcare systems around the world. Hence, there is a constant need to develop new antibiotics to fight resistant bacteria, among other important social and economic measures. In this regard, murepavadin is a cyclic antibacterial peptide in development. The synthesis of murepavadin was undertaken in order to optimize the preparative protocol and scale-up, in particular, the use of new activation reagents. In our hands, classical approaches using carbodiimide/hydroxybenzotriazole rendered low yields. The use of novel carbodiimide and reagents based on OxymaPure® and Oxy-B is discussed together with the proper use of chromatographic conditions for the adequate characterization of peptide crudes. Higher yields and purities were obtained. Finally, the antimicrobial activity of different synthetic batches was tested in three Pseudomonas aeruginosa strains, including highly resistant ones. All murepavadin batches yielded the same highly active MIC values and proved that the chiral integrity of the molecule was preserved throughout the whole synthetic procedure. [ABSTRACT FROM AUTHOR]

Pleopeltis crassinervata is a fern documented in ethnobotanical records for its use in Mexican traditional medicine to treat gastric disorders and mouth ulcers. Consequently, conducting biological and pharmacological assays is crucial to validate the therapeutic efficacy of this plant within the context of traditional medicine. In the present study, we investigated the biological activity of extracts and fractions obtained from P. crassinervata organs against bacteria (Salmonella typhimurium, Salmonella typhi, Staphylococcus aureus, Proteus mirabilis, Shigella flexneri, Bacillus subtilis, Escherichia coli) and Trichomonas vaginalis using in vitro models. The precipitate fraction obtained from the frond methanolic extract showed significant antibacterial activity (minimal inhibitory concentration [MIC] 120 µg/mL) against the Staphylococcus aureus strain and was effective against both Gram-positive and Gram-negative bacteria. The hexane fraction also obtained from frond methanolic extract, showed a trichomonacidal effect with an IC50 of 82.8 μg/mL and a low cytotoxic effect. Hsf6 exhibited the highest activity against T. vaginalis, and the GC-MS analysis revealed that the predominant compound was 16-pregnenolone. The remaining identified compounds were primarily terpene-type compounds. [ABSTRACT FROM AUTHOR]

As the risk of antibiotic-resistant bacteria increases, interest in non-antibiotic treatment is also increasing. Among the methods used in non-antibiotic therapy, natural antibiotics such as essential oils have disadvantages such as low efficiency. In the case of phototherapy, the light used for antibacterial activities has low penetration into the human body because of its short wavelength, making it of low medical utility. To solve this problem, this study aimed to determine conditions for enhancing the antibacterial activity of natural phytochemicals and visible light. Four natural phytochemical extracts that showed high antibacterial properties in previous studies were analyzed. Synergistic effects on antibacterial activity and cytotoxicity were determined when natural phytochemical extracts and visible light were simultaneously used. As a result, it was confirmed that the antibacterial activity increased by four times when Sanguisorba officinalis L. was irradiated with 465 nm for 10 min and 520 nm for 40 min, and Uncaria gambir Roxb. was irradiated with 465 nm for 10 min and 520 nm for 60 min compared to when Sanguisorba officinalis L. and Uncaria gambir Roxb. were used alone. The synergistic effect on antibacterial activity was independent of the absorption peak of the natural phytochemical extracts. In addition, in the case of natural phytochemical extracts with improved antibacterial activity, it was confirmed that the improvement of antibacterial activity was increased in inverse proportion to the light irradiation wavelength and in proportion to the light irradiation time. The antibacterial activity was enhanced regardless of antibiotic resistance. In the case of cytotoxicity, it was confirmed that there was no toxicity to A549 cells when treated with 465 nm, the shortest wavelength among the natural phytochemical extracts. These results show how to replace blue light, which has been underutilized due to its low transmittance and cytotoxicity. They also demonstrate the high medical potential of using natural phytochemical and visible light as a combination therapy. [ABSTRACT FROM AUTHOR]

The fermentation of a soil-derived fungus Acremonium sp. led to the isolation of thirteen ascochlorin congeners through integrated genomic and Global Natural Product Social (GNPS) molecular networking. Among the isolated compounds, we identified two unusual bicyclic types, acremochlorins O (1) and P (2), as well as two linear types, acremochlorin Q (3) and R (4). Compounds 1 and 2 contain an unusual benzopyran moiety and are diastereoisomers of each other, the first reported for the ascochlorins. Additionally, we elucidated the structure of 5, a 4-chloro-5-methylbenzene-1,3-diol with a linear farnesyl side chain, and confirmed the presence of eight known ascochlorin analogs (6–13). The structures were determined by the detailed interpretation of 1D and 2D NMR spectroscopy, MS, and ECD calculations. Compounds 3 and 9 showed potent antibacterial activity against Staphylococcus aureus and Bacillus cereus, with MIC values ranging from 2 to 16 μg/mL. [ABSTRACT FROM AUTHOR]

Calcium phosphate (CaP) particles immobilizing antibacterial agents have the potential to be used as dental disinfectants. In this study, we fabricated CaP particles with immobilized ciprofloxacin (CF), a commonly prescribed antibacterial agent, via a coprecipitation process using a supersaturated CaP solution. As the aging time in the coprecipitation process increased from 2 to 24 h, the CaP phase in the resulting particles transformed from amorphous to low-crystalline hydroxyapatite, and their Ca/P elemental ratio, yield, and CF content increased. Despite the higher CF content, the particles aged for 24 h displayed a slower release of CF in a physiological salt solution, most likely owing to their crystallized matrix (less soluble hydroxyapatite), than those aged for 2 h, whose matrix was amorphous CaP. Both particles exhibited antibacterial and antibiofilm activities along with an acid-neutralizing effect against the major oral bacteria, Streptococcus mutans, Porphyromonas gingivalis, and Actinomyces naeslundii, in a dose-dependent manner, although their dose–response relationship was slightly different. The aging time in the coprecipitation process was identified as a governing factor affecting the physicochemical properties of the resulting CF-immobilized CaP particles and their functionality as a dental disinfectant. [ABSTRACT FROM AUTHOR]

Increasing antimicrobial resistance (AMR) challenges conventional antibiotics, prompting the search for alternatives. Extracellular vesicles (EVs) from pasteurised cattle milk offer promise, due to their unique properties. This study investigates their efficacy against five pathogenic bacteria, including Staphylococcus aureus ATCC 25923, aiming to combat AMR and to develop new therapies. EVs were characterised and tested using various methods. Co-culture experiments with S. aureus showed significant growth inhibition, with colony-forming units decreasing from 2.4 × 105 CFU/mL (single dose) to 7.4 × 104 CFU/mL (triple doses) after 12 h. Milk EVs extended lag time (6 to 9 h) and increased generation time (2.8 to 4.8 h) dose-dependently, compared to controls. In conclusion, milk EVs exhibit dose-dependent inhibition against S. aureus, prolonging lag and generation times. Despite limitations, this suggests their potential in addressing AMR. [ABSTRACT FROM AUTHOR]

This work presents the design, synthesis and biological activity of novel N-substituted benzimidazole carboxamides bearing either a variable number of methoxy and/or hydroxy groups. The targeted carboxamides were designed to investigate the influence of the number of methoxy and/or hydroxy groups, the type of substituent placed on the N atom of the benzimidazole core and the type of substituent placed on the benzimidazole core on biological activity. The most promising derivatives with pronounced antiproliferative activity proved to be N-methyl-substituted derivatives with hydroxyl and methoxy groups at the phenyl ring and cyano groups on the benzimidazole nuclei with selective activity against the MCF-7 cell line (IC50 = 3.1 μM). In addition, the cyano-substituted derivatives 10 and 11 showed strong antiproliferative activity against the tested cells (IC50 = 1.2–5.3 μM). Several tested compounds showed significantly improved antioxidative activity in all three methods compared to standard BHT. In addition, the antioxidative activity of 9, 10, 32 and 36 in the cells generally confirmed their antioxidant ability demonstrated in vitro. However, their antiproliferative activity was not related to their ability to inhibit oxidative stress nor to their ability to induce it. Compound 8 with two hydroxy and one methoxy group on the phenyl ring showed the strongest antibacterial activity against the Gram-positive strain E. faecalis (MIC = 8 μM). [ABSTRACT FROM AUTHOR]