Green and environmentally friendly synthesis of silver nanoparticles with antibacterial properties from some medicinal plants.

Recently there have been a variety of methods to synthesize silver nanoparticles, among which the biosynthesis method is more noticeable due to features like being eco-friendly, simple, and cost-efficient. The present study aims for the green synthesis of silver nanoparticles from the extract of the three plants A. wilhelmsi, M. chamomilla, and C. longa; moreover, it pledges to measure the antibacterial activity against some variants causing a skin rash. The morphology and size of the synthesized silver nanoparticles were evaluated by UV.vis, XRD, SEM, and FTIR analyses. Then results showed a color alteration from light yellow to dark brown and the formation of silver nanoparticles. The absorption peak with the wavelength of approximately 450 nm resulting from the Spectrophotometry analysis confirmed the synthesis of silver nanoparticles. The presence of strong and wide peaks in FTIR indicated the presence of OH groups. The SEM results showed that most synthesized nanoparticles had a spherical angular structure and their size was about 10 to 20 nm. The highest inhibition power was demonstrated by silver nanoparticles synthesized from the extract combined from all three species against Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis (23 mm) which had a performance far more powerful than the extract. Thus, it can be understood that the nanoparticles synthesized from these three species can act as potential environment-friendly alternatives to inhibit some variations causing skin disorders; an issue that calls for further clinical studies.

Utilizing bio-synthesis of nanomaterials as biological agents for controlling soil-borne diseases in pepper plants: root-knot nematodes and root rot fungus.

The utilization of Trichoderma longibrachiatum filtrate as a safe biocontrol method for producing zinc nanoparticles is a promising approach for managing pests and diseases in agricultural crops. The identification of Trichoderma sp. was achieved through PCR amplification and sequencing of 18s as ON203115, while the synthesis of ZnO-NPs was accomplished by employing Trichoderma filtration. The presence of ZnO-NPs was confirmed by observing a color change to dark green, along with the use of visible and UV spectrophotometers, and the formation and chemical structure of ZnO-NPs were examined. Direct exposure to ZnO-NPs exhibited a significant inhibitory effect on the growth of Fusarium oxysporum at 80.73% compared with control. Also, the percent mortality of Meloidogyne incognita second juveniles stage (J2s) results showed 11.82%, 37.63%, 40.86%, and 89.65% after 6, 12, 24, and 72 h, respectively in vitro. Disease resistance was assessed in the greenhouse against M. incognita and F. oxysporum using the drench application of ZnO-NPs. The application of ZnO-NPs significantly reduced the disease severity of F. oxysporum and improved the quality and quantity of sweet pepper yield. In addition, the application of ZnO-NPs to M. incognita resulted in a significant reduction in the number of nematode galls, egg masses per root, eggs/egg mass, and females by 98%, 99%, 99.9%, and 95.5% respectively.Furthermore, it was observed that the application of ZnO-NPs to pepper plants not only inhibited the growth of F. oxysporum and M. incognita, but also promoted the recovery of pepper plants as indicated by improvements in stem length by 106%, root length 102%, fresh weight 112%, root fresh weight 107%, and leaf area 118% compared to healthy control plants. Additionally, real-time PCR application and DD-PCR technique revealed that the application of ZnO-NPs stimulated the secretion of certain enzymes. These findings suggest that the biosynthesized ZnO-NPs possess anti-nematode and antifungal properties, making them effective for protecting plants against M. incognita and F. oxysporum invasion in soil. This study significantly contributes to our understanding of the nematicidal and fungicidal activities of ZnO-NPs in suppressing soil-borne diseases.

Green synthesis of a dual-functional sulfur nanofertilizer to promote growth and enhance salt stress resilience in faba bean.

BACKGROUND: Salinity is a major abiotic stress, and the use of saline water in the agricultural sector will incur greater demand under the current and future climate changing scenarios. The objective of this study was to develop a dual-functional nanofertilizer capable of releasing a micronutrient that nourishes plant growth while enhancing salt stress resilience in faba bean (Vicia faba L.). RESULTS: Moringa oleifera leaf extract was used to synthesize sulfur nanoparticles (SNPs), which were applied as a foliar spray at different concentrations (0, 25, 50, and 100 mg/l) to mitigate the negative effects of salt stress (150 mM NaCl) on faba bean plants. The SNPs were characterized and found to be spherical in shape with an average size of 10.98 ± 2.91 nm. The results showed that salt stress had detrimental effects on the growth and photosynthetic performance (Fv/Fm) of faba bean compared with control, while foliar spraying with SNPs improved these parameters under salinity stress. SNPs application also increased the levels of osmolytes (soluble sugars, amino acids, proline, and glycine betaine) and nonenzymatic antioxidants, while reducing the levels of oxidative stress biomarkers (MDA and H2O2). Moreover, SNPs treatment under salinity stress stimulated the activity of antioxidant enzymes (ascorbate peroxidase (APX), and peroxidase (POD), polyphenol oxidase (PPO)) and upregulated the expression of stress-responsive genes: chlorophyll a-b binding protein of LHCII type 1-like (Lhcb1), ribulose bisphosphate carboxylase large chain-like (RbcL), cell wall invertase I (CWINV1), ornithine aminotransferase (OAT), and ethylene-responsive transcription factor 1 (ERF1), with the greatest upregulation observed at 50 mg/l SNPs. CONCLUSION: Overall, foliar application of sulfur nanofertilizers in agriculture could improve productivity while minimizing the deleterious effects of salt stress on plants. Therefore, this study provides a strong foundation for future research focused on evaluating the replacement of conventional sulfur-containing fertilizers with their nanoforms to reduce the harmful effects of salinity stress and enhance the productivity of faba beans.

Trichoderma cf. asperellum and plant-based titanium dioxide nanoparticles initiate morphological and biochemical modifications in Hordeum vulgare L. against Bipolaris sorokiniana.

BACKGROUND: Spot blotch is a serious foliar disease of barley (Hordeum vulgare L.) plants caused by Bipolaris sorokiniana, which is a hemibiotrophic ascomycete that has a global impact on productivity. Some Trichoderma spp. is a promising candidate as a biocontrol agent as well as a plant growth stimulant. Also, the application of nanomaterials in agriculture limits the use of harmful agrochemicals and helps improve the yield of different crops. The current study was carried out to evaluate the effectiveness of Trichoderma. cf. asperellum and the biosynthesized titanium dioxide nanoparticles (TiO2 NPs) to manage the spot blotch disease of barley caused by B. sorokiniana and to assess the plant's innate defense response. RESULTS: Aloe vera L. aqueous leaf extract was used to biosynthesize TiO2 NPs by reducing TiCl4 salt into TiO2 NPs and the biosynthesized NPs were detected using SEM and TEM. It was confirmed that the NPs are anatase-crystalline phases and exist in sizes ranging from 10 to 25 nm. The T. cf. asperellum fungus was detected using morphological traits and rDNA ITS analysis. This fungus showed strong antagonistic activity against B. sorokiniana (57.07%). Additionally, T. cf. asperellum cultures that were 5 days old demonstrated the best antagonistic activity against the pathogen in cell-free culture filtrate. Also, B. sorokiniana was unable to grow on PDA supplemented with 25 and 50 mg/L of TiO2 NPs, and the diameter of the inhibitory zone increased with increasing TiO2 NPs concentration. In an in vivo assay, barley plants treated with T. cf. asperellum or TiO2 NPs were used to evaluate their biocontrol efficiency against B. sorokiniana, in which T. cf. asperellum and TiO2 NPs enhanced the growth of the plant without displaying disease symptoms. Furthermore, the physiological and biochemical parameters of barley plants treated with T. cf. asperellum or TiO2 NPs in response to B. sorokiniana treatment were quantitively estimated. Hence, T. cf. asperellum and TiO2 NPs improve the plant's tolerance and reduce the growth inhibitory effect of B. sorokiniana. CONCLUSION: Subsequently, T. cf. asperellum and TiO2 NPs were able to protect barley plants against B. sorokiniana via enhancement of chlorophyll content, improvement of plant health, and induction of the barley innate defense system. The present work emphasizes the major contribution of T. cf. asperellum and the biosynthesized TiO2 NPs to the management of spot blotch disease in barley plants, and ultimately to the enhancement of barley plant quality and productivity.

Green Synthesis and Biosafety Assessment of MXene.

The rise of MXene-based materials with fascinating physical and chemical properties has attracted wide attention in the field of biomedicine, because it can be exploited to regulate a variety of biological processes. The biomedical applications of MXene are still in its infancy, nevertheless, the comprehensive evaluation of MXene's biosafety is desperately needed. In this review, the composition and the synthetic methods of MXene materials are first introduced from the view of biosafety. The evaluation of the interaction between MXene and cells, as well as the safety of different forms of MXene applied in vivo are then discussed. This review provides a basic understanding of MXene biosafety and may bring new inspirations to the future applications of MXene-based materials in biomedicine.

Copper Dispersed Covalent Organic Framework for Azide-Alkyne Cycloaddition and Fast Synthesis of Rufinamide in Water.

A crystalline porous bipyridine-based Bpy-COF with a high BET surface area (1864 m2 g-1) and uniform mesopore (4.0 nm) is successfully synthesized from 1,3,5-tris-(4'-formyl-biphenyl-4-yl)triazine and 5,5'-diamino-2,2'-bipyridine via a solvothermal method. After Cu(I)-loading, the resultant Cu(I)-Bpy-COF remained the ordered porous structure with evenly distributed Cu(I) ions at a single-atom level. Using Cu(I)-Bpy-COF as a heterogeneous catalyst, high conversions for cycloaddition reactions are achieved within a short time (40 min) at 25 °C in water medium. Moreover, Cu(I)-Bpy-COF proves to be applicable for aromatic and aliphatic azides and alkynes bearing various substituents such as ester, hydroxyl, amido, pyridyl, thienyl, bulky triphenylamine, fluorine, and trifluoromethyl groups. The high conversions remain almost constant after five cycles. Additionally, the antiepileptic drug (rufinamide) is successfully prepared by a simple one-step reaction using Cu(I)-Bpy-COF, proving its practical feasibility for pharmaceutical synthesis.

N, O-Doped Walnut-Like Porous Carbon Composite Microspheres Loaded with Fe/Co Nanoparticles for Adjustable Electromagnetic Wave Absorption.

This study addresses the challenge of designing simple and environmentally friendly methods for the preparation of effective electromagnetic wave (EMW) absorbing materials with tailored microstructures and multi-component regulation. N, O doped walnut-like porous carbon composite microspheres loaded with FeCo nanoparticles (WPCM/Fe-Co) are synthesized through high-temperature carbonization combined with soap-free emulsion polymerization and hydrothermal methods, avoiding the use of toxic solvents and complex conditions. The incorporation of magnetic components enhances magnetic loss, complementing dielectric loss to optimize EMW attenuation. The unique walnut-like morphology further improves impedance matching. The proportions of Fe and Co components can be adjusted to regulate the material's reflection loss, thickness, and bandwidth, allowing for fine-tuning of absorption performance. At a low filling ratio (16.7%), the optimal WPCM/Fe-Co composites exhibit a minimum reflection loss (RLmin) of -48.34 dB (10.33 GHz, 3.0 mm) and an overall effective absorbing bandwidth (EAB) covering the entire C bands, X bands, and Ku bands. This work introduces a novel approach to composition regulation and presents a green synthesis method for magnetic carbon composite absorbers with high-performance EMW absorption at low loading.

Molecular farming for sustainable production of clinical-grade antimicrobial peptides.

Antimicrobial peptides (AMPs) are emerging as next-generation therapeutics due to their broad-spectrum activity against drug-resistant bacterial strains and their ability to eradicate biofilms, modulate immune responses, exert anti-inflammatory effects and improve disease management. They are produced through solid-phase peptide synthesis or in bacterial or yeast cells. Molecular farming, i.e. the production of biologics in plants, offers a low-cost, non-toxic, scalable and simple alternative platform to produce AMPs at a sustainable cost. In this review, we discuss the advantages of molecular farming for producing clinical-grade AMPs, advances in expression and purification systems and the cost advantage for industrial-scale production. We further review how 'green' production is filling the sustainability gap, streamlining patent and regulatory approvals and enabling successful clinical translations that demonstrate the future potential of AMPs produced by molecular farming. Finally, we discuss the regulatory challenges that need to be addressed to fully realize the potential of molecular farming-based AMP production for therapeutics.

Escaping the ESKAPE pathogens: A review on antibiofilm potential of nanoparticles.

ESKAPE pathogens, a notorious consortium comprising Enterococcusfaecium, Staphylococcusaureus, Klebsiellapneumoniae, Acinetobacterbaumannii, Pseudomonasaeruginosa, and Enterobacter species, pose formidable challenges in healthcare settings due to their multidrug-resistant nature. The increasing global cases of antimicrobial-resistant ESKAPE pathogens are closely related to their remarkable ability to form biofilms. Thus, understanding the unique mechanisms of antimicrobial resistance of ESKAPE pathogens and the innate resilience of biofilms against traditional antimicrobial agents is important for developing innovative strategies to establish effective control methods against them. This review offers a thorough analysis of biofilm dynamics, with a focus on the general mechanisms of biofilm formation, the significant contribution of persister cells in the resistance mechanisms, and the recurrence of biofilms in comparison to planktonic cells. Additionally, this review highlights the potential strategies of nanoparticles for managing biofilms in the ESKAPE group of pathogens. Nanoparticles, with their unique physicochemical properties, provide promising opportunities for disrupting biofilm structures and improving antimicrobial effectiveness. The review has explored interactions between nanoparticles and biofilms, covering a range of nanoparticle types such as metal, metal-oxide, surface-modified, and functionalized nanoparticles, along with organic nanoparticles and nanomaterials. The additional focus of this review also encompasses green synthesis techniques of nanoparticles that involve plant extract and supernatants from bacterial and fungal cultures as reducing agents. Furthermore, the use of nanocomposites and nano emulsions in biofilm management of ESKAPE is also discussed. To conclude, the review addresses the current obstacles and future outlooks in nanoparticle-based biofilm management, stressing the necessity for further research and development to fully exploit the potential of nanoparticles in addressing biofilm-related challenges.

Green synthesis of biogenic selenium nanoparticles functionalized with ginger dietary extract targeting virulence factor and biofilm formation in Candida albicans.

To treat the systemic infections caused by Candida albicans (C. albicans), various drugs have been used, however, infections still persisted due to virulence factors and increasing antifungal resistance. As a solution to this problem, we synthesized selenium nanoparticles (SeNPs) by using Bacillus cereus bacteria. This is the first study to report a higher (70 %) reduction of selenite ions into SeNPs in under 6 h. The as-synthesized, biogenic SeNPs were used to deliver bioactive constituents of aqueous extract of ginger for inhibiting the growth and biofilm (virulence factors) in C. albicans. UV-visible spectroscopy revealed a characteristic absorption at 280 nm, and Raman spectroscopy showed a characteristic peak shift at 253 cm-1 for the biogenic SeNPs. The synthesized SeNPs are spherical with 240-250 nm in size as determined by electron microscopy. Fourier transform infrared spectroscopy confirmed the functionalization of antifungal constituents of ginger over the SeNPs (formation of Ginger@SeNPs nanoconjugates). In contrast to biogenic SeNPs, nanoconjugates were active against C. albicans for inhibiting growth and biofilm formation. In order to reveal antifungal mechanism of nanoconjugates', real-time polymerase chain reaction (RT-PCR) analysis was performed, according to RT-PCR analysis, the nanoconjugates target virulence genes involved in C. albicans hyphae and biofilm formation. Nanoconjugates inhibited 25 % growth of human embryonic kidney (HEK) 293 cell line, indicating moderate cytotoxicity of active nanoconjugates in an in-vitro cytotoxicity study. Therefore, biogenic SeNPs conjugated with ginger dietary extract may be a potential antifungal agent and drug carrier for inhibiting C. albicans growth and biofilm formation.

New arsenals for old armour: Biogenic nanoparticles in the battle against drug-resistant Candidaalbicans.

Candida albicans is a common commensal fungus and fourth most frequent causative agent of nosocomial infections including life-threatening invasive candidiasis in humans. The effectiveness of present antifungal therapies using azoles, polyenes, flucytosine and echinocandins has plateaued in managing fungal infections. The limitations of these antifungal drugs are related to polymorphic morphology, biofilm formation, emergence of drug-resistant strains and production of several virulence factors. Development of new antifungal agents, which can particularly afflict multiple cellular targets and limiting evolving resistant strains are needed. Recently, metal nanoparticles have emerged as a source of new antifungal agents for antifungal formulations. Furthermore, green nanotechnology deals with the use of biosynthetic routes that offer new avenue for synthesizing antifungal nanoparticles coupled with less toxic chemical inventory and environmental sustainability. This article reviews the recent developments on C. albicans pathogenesis, biofilm formation, drug resistance, mode of action of antifungal drugs and antifungal activities of metal nanoparticles. The antifungal efficacy and mode of action of metal nanoparticles are described in the context of prospective therapeutic applications.

Antimicrobial efficiency against fish pathogens on the green synthesized silver nanoparticles.

Fish-borne pathogens such as A. hydrophila and F. aquidurense are the most resistant strains in pisciculture farming. Removing the aforementioned pathogens without antibiotics presents a formidable challenge. To overcome this problem, silver nanoparticles (AgNPs) are synthesized using silver nitrate, water medium, and as an AzadirachtaIndica leaf extract via the green synthesis route. X-ray diffraction (XRD) pattern results authenticate the synthesized material is the face-centered cubic structure of silver. The optical absorption edge of the synthesized product was found at the wavelength of 440 nm from the UV-visible spectra, which is confirmed to relate to the Surface Plasmon Resonance peaks of silver particles. In addition, the optical band gap value of the synthesized Ag sample is measured to be 2.81 eV from the obtained optical absorption spectra. EDX spectrum of the synthesized product also supports confirming the silver particle formation. The FT-IR spectra of the neem extract and silver nanoparticles showed their characteristic functional groups, respectively. The presence of bands between 1000 cm-1 to 500 cm-1 indicates to the formation of silver particles. Spherical particles appeared in the synthesized Ag using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The particle size of Ag NPs was measured as 40 nm and 62 ± 10 nm by TEM and Dynamic Light Scattering (DLS). The zeta potential was also measured as -12 mV showing the synthesized sample's stable nature. Using the DPPH assay, synthesized AgNPs were taken along with the various concentrations of ascorbic acid (20, 40, 60, 80, and 100 µg/mL) to examine the free radical scavenging activity (RSA). RSA value is higher (84 ± 2 %) for synthesized AgNPs at higher concentration (100 µg/mL) than 21 ± 2 % at low concentration (100 µg/mL). The antimicrobial efficacy of the AgNPs against A. hydrophila and F. aquidurense was performed through the agar diffusion method and its results showed the inhibitory zones of the F.aquidurense and A. hydrophila were measured as 25 ± 3 mm, and 28 ± 4 mm respectively. The synthesized Ag particles showed excellent antimicrobial and antioxidant properties confirmed by antimicrobial and DPPH experiments. It implies that the green synthesized silver nanoparticles could be a good alternative for antibiotics in aquaculture farms. The exposure of low concentrations of silver nanoparticles to zebrafish and brine shrimp does not affect the viability and morphology. The exposure of silver nanoparticles in the fisheries in optimized concentration and time could control the fish-borne pathogens without antibiotics.

Biosynthesis of silver nanoparticle using Bacillus licheniformis culture-supernatant for combating pathogenic biofilms.

Bacterial biofilms pose a significant threat to healthcare due to their recalcitrance to antibiotics and disinfectants. This study explores the anti-biofilm potential of Bacillus licheniformis cell-free culture supernatant (CFS) and its derived silver nanoparticles (bSNPs) against Staphylococcus aureus and Pseudomonas aeruginosa. The CFS exhibited potent anti-biofilm activity against both bacterial species, even at low concentrations, while devoid of significant bactericidal effects, mitigating resistance risks. Characterization studies revealed the non-proteinaceous nature and thermal stability of the CFS's anti-biofilm agent, suggesting a robust and heat-resistant structure. Green synthesis of bSNPs from CFS resulted in nanoparticles with significant anti-biofilm properties, particularly against P. aeruginosa, indicating differences in susceptibility between the bacterial species. Epifluorescence microscopy confirmed bSNPs' ability to inhibit and partially disrupt biofilm formation without inducing cellular lysis. The study highlights the potential of B. licheniformis CFS and bSNPs as promising biofilm control agents, offering insights into their mechanisms of action and broad-spectrum efficacy. Further research elucidating the underlying molecular mechanisms and identifying specific bioactive compounds is warranted for the translation of these findings into clinically relevant applications for combating biofilm-associated infections.

Exploring non-cytotoxic, antioxidant, and anti-inflammatory properties of selenium nanoparticles synthesized from Gymnema sylvestre and Cinnamon cassia extracts for herbal nanomedicine.

The increasing need for pharmaceutical agents that possess attributes such as safety, cost-effectiveness, environmental sustainability, and absence of side effects has driven the advancement of nanomedicine research, which lies at the convergence of nanotechnology and medicine. AIMS AND OBJECTIVES: The study aimed to synthesize non-toxic selenium nanoparticles (SeNPs) using Gymnema sylvestre (G. sylvestre) and Cinnamon cassia (C. cassia) extracts. It also sought to develop and evaluate versatile nanomedicine formulations i.e. selenium nanoparticles of G. sylvestre and C. cassia (SeNPs), drug (lupeol) loaded SeNPs (DLSeNPs), drug-loaded and coated (PEG) SeNPs (DLCSeNPs) without side effects. METHODS: The SeNPs formulations were hydrothermally synthesized, loaded with lupeol to improve efficacy, coated with polyethylene glycol (PEG) for targeted delivery, and characterized using UV-Vis spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), zeta potential analysis, size distribution analysis, and X-ray diffraction (XRD). Hemolytic cytotoxicity, 2,2-Diphenyl-1-picrylhydzayl (DPPH), total Reducing power, and total antioxidant capacity (TAC) antioxidant assays, carrageenan-induced paw edema, and histological studies were used to estimate the acute anti-inflammatory activity of the synthesized SeNPs. RESULTS: The final form of PEGylated and drug (lupeol)-loaded selenium nanoparticles (DLCSeNPs) exhibited an average particle size ranging from 100 to 500 nm as evidenced by SEM, and Zeta potential results. These nanoparticles demonstrated no cytotoxic effects and displayed remarkable antioxidant (IC50 values 19.29) and anti-inflammatory capabilities. These results were fed into Graph-pad Prism 5 software and analyzed by one-way ANOVA, followed by Tukey's post hoc test (p < 0.001). All nano-formulations exhibited significant overall antioxidant activity, with IC50 values ≤ 386 (p < 0.05) as analyzed by ANOVA. The study's results suggest that G. sylvestre outperformed C. cassia in terms of reducing 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical, potassium ferricyanide, and ammonium molybdate in respective antioxidant assays. As far as anti-inflammatory activities are concerned drug (lupeol)-loaded and PEG-coated G. sylvestre SeNPs exhibited the highest anti-inflammatory potential from all other nano-formulations including drug (lupeol)-loaded and PEG-coated C. cassia SeNPs, as exhibited to reduce the release of pro-inflammatory signals i.e. cytokines and NF-kB, making them innovative anti-inflammatory nanomedicine. CONCLUSION: The study synthesized lupeol-loaded and PEG-coated SeNPs, showcasing the potential for biocompatible, cost-effective anti-inflammatory nanomedicines. G. Sylvester's superior antioxidant and anti-inflammatory performance than Cinnamon cassia emphasizes medicinal plant versatility.

Electrosynthesis of 1,2,3-Benzotriazines through an Iodide-Catalyzed Skeletal Editing of 3-Aminoindazoles.

This report describes an environmentally benign synthesis of 1,2,3-benzotriazines through an iodide-catalyzed electro-oxidative N-centered [1,2]-rearrangement of 3-aminoindazoles. The developed method demonstrates the activation of heteroatoms via electrochemically generated reactive iodide species without using any metal catalysts and peroxides. The protocol features practical and mild reaction conditions and displays a wide substrate scope. Various mechanistic experiments and cyclic voltammetric studies have been instrumental in elucidating the reaction mechanism, operating via a skeletal rearrangement of 3-aminoindazoles.

Photochemical Aerobic Upcycling of Polystyrene Plastics via Synergistic Indirect HAT Catalysis.

Plastic pollution constitutes an evergrowing urgent environmental problem, since overaccumulation of plastic waste, arising from the immense increase of the production of disposable plastic products, overcame planet's capacity to properly handle them. Chemical upcycling of polystyrene constitutes a convenient method for the conversion of plastic waste into high-added value chemicals, suggesting an attractive perspective in dealing with the environmental crisis. We demonstrate herein a novel, easy-to-perform organocatalytic photoinduced aerobic protocol, which proceeds via synergistic indirect hydrogen atom transfer (HAT) catalysis under LED 390 nm Kessil lamps as the irradiation source. The developed method employs a BrCH2CN-thioxanthone photocatalytic system and was successfully applied to a variety of everyday-life plastic products, leading to the isolation of benzoic acid after simple base-acid work up in yields varying from 23-49 %, while a large-scale experiment was successfully performed, suggesting that the photocatalytic step is susceptible to industrial application.

Synthesis of Pyridazino[4,5-b]indoles by [3+3] Annulation of 2-Alkenylindoles and Hydrazonyl Chlorides.

A novel [3+3] annulation reaction of 2-alkenylindoles with hydrazonyl chlorides in the presence of base for the formation of pyridazino[4,5-b]indoles was developed. This approach provided a convenient and efficient way to synthesize a series of functionalized pyridazino[4,5-b]indoles derivatives. The method exhibited a broad substrate scope and provided the corresponding pyridazino[4,5-b]indoles products with excellent yields.

Synthesized arsenic nanoparticles and their high potential in biomedical applications: A review.

Arsenic with the scientific name AS is an element that exists everywhere. It is the fourth among the abundant elements in water, the twelfth in the human body, and the twentieth in the earth's crust. This element exists in sulfide, carbonate, and elemental forms. Different names of arsenic are known as white arsenic (As2O3), yellow arsenic (As2S3), and red arsenic (As4S4). Nowadays, due to its unique properties, arsenic has received much attention from researchers for use in the synthesis of arsenic nanoparticles. According to various studies, arsenic nanoparticles are synthesized by various methods, including biological, physical, and chemical, and it has been shown that the synthetic method used is very important because it has a significant effect on their shape, size, and biological function. Arsenic nanoparticles are among the nanoparticles that have attracted the attention of researchers due to their particle potential as well as their anticancer, antitumor, cytotoxic, and antimicrobial applications. Therefore, the aim of this study is to investigate arsenic nanoparticles biosynthesized by different physical, biological, and chemical methods and their biomedical applications.

Study of ZnO nanoparticle-doped dental adhesives on enamels with fluorosis: Electron microscopy, elemental composition and shear bond strength analysis.

This study aimed to evaluate dental adhesives containing different concentrations of zinc oxide nanoparticles (ZnO-NPs) for their use in the treatment of dental fluorosis, observe the interaction of the adhesive on healthy enamel surfaces and with mild and moderate fluorosis, measure the adhesive strength and fluorosis, and determine the phosphorus (P) and calcium (Ca) content on these surfaces, as a reference for the potential use of this adhesive with ZnO-NPs for dental fluorosis treatment. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to characterise the ZnO-NPs and analyse the weight percentages of P and Ca in the enamel using X-ray energy dispersive spectroscopy (EDS) and the adhesive strength using a universal mechanical testing machine. FESEM characterisation revealed that the ZnO-NPs were less than 100 nm in size, with quasi-spherical and hexagonal prism shapes. The synthesis of the ZnO-NPs was confirmed by TEM, revealing their hexagonal crystalline structure. The adhesive strength by the universal mechanical testing machine showed that the adhesive with a 3% wt. concentration of ZnO-NPs was better in the three groups of teeth, showing higher adhesive strength in teeth with mild (15.15 MPa) and moderate (12.76 MPa) fluorosis surfaces, and was even higher than that in healthy teeth (9.65 MPa). EDS analysis showed that teeth with mild and moderate fluorosis had the highest weight percentages of P and Ca, but there were no statistically significant differences compared to healthy teeth and teeth treated with adhesives. Lay description: This study focused on testing a new dental adhesive containing small particles called ZnO nanoparticles (ZnO-NPs). This study aimed to demonstrate whether this adhesive with ZnO-NPs could be useful for treating dental fluorosis by improving its adhesion to teeth. One of the first objectives was to determine whether the dental adhesive could adhere better to teeth affected by mild or moderate fluorosis than to healthy teeth by measuring whether the levels of two important elements for healthy teeth, calcium (Ca) and phosphorus (P), were affected by the adhesive. The size and shape of the small particles and teeth with mild or moderate fluorosis were observed using scanning electron microscopy. The nanoparticles were small (< 100 nm) and had specific quasi-spherical and hexagonal prismatic shapes. More damage to the enamel was observed in teeth with mild or moderate fluorosis than in healthy teeth. The adhesive strength test demonstrated that the dental adhesive with 3% ZnO-NPs had the best adhesion on all healthy conditions of teeth. It was particularly effective in teeth with mild or moderate fluorosis. Finally, the evaluation of the levels of P and Ca on the enamel showed that teeth with fluorosis had higher levels of these elements, but using the dental adhesive with ZnO-NPs did not change the levels of these elements significantly because the adhesive avoided greater detachment because of greater adhesion to these surfaces. In conclusion, adding these small particles to dental adhesives could be an option for treating teeth affected by fluorosis. It stuck well and did not affect the levels of the important elements in the teeth.

Induction of tomato plant biochemical immune responses by the synthesized zinc oxide nanoparticles against wilt-induced Fusarium oxysporum.

The current study used zinc oxide nanoparticles (ZnO-NPs) to protect the tomato plant against Fusarium wilt. Gamma rays were used to synthesize ZnO-NPs, and the designed ZnO-NPs were characterized using high-resolution transmission electron microscopy (HRTEM), scanning electron microscope (SEM), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDX), and ultraviolet-visible (UV-Vis.) spectroscopy. We found that the 20 kGy dose is the most effective for ZnO-NPs synthesis, with the highest O.D. = 1.65 (diluted 3 times) at 400 nm. The scale of ZnO-NPs ranged from 10.45 to 75.25 nm with an average diameter of 40.20 nm. The results showed that the designed ZnO-NPs showed promising activity as a potent inducer of plant physiological immunity against Fusarium wilt disease. Likewise, ZnO-NPs significantly reduced the wilt disease symptoms incidence by 28.57% and high protection by 67.99% against F. oxysporum. Additionally, infected tomato plants treated with ZnO-NPs show improved shoot length (44.71%), root length (40.0%), number of leaves (60.0 %), chlorophyll a (36.93%), chlorophyll b (16.46%), and carotenoids (21.87%) versus infected plants. Notably, in the treatment of tomato seedlings, the beneficial effects of ZnO-NPs extended to increase not only in osmolyte contents but also total phenol contents in comparison with control plants. In conclusion, the designed ZnO-NPs can control Fusarium wilt disease and improve and develop biochemical compounds responsible for defense against fusarial infection.