Iron Oxide Nanoparticles: Biosynthesis,Magnetic Behavior,Cytotoxic Effect

Iron oxide nanoparticles have attracted much attention because of their superparamagnetic properties and their potential applications in many fields such as magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry (SPMR), and high-sensitivity biomolecule magnetic resonance imaging (MRI) for medical diagnosis and therapeutics. In this study, iron oxide nanoparticles (Fe₂O₃ NPs) have been synthesized using a taranjabin (camelthorn or persian manna) aqueous solution. The synthesized Fe₂O₃ NPs were identified through powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), field energy scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX), vibrating-sample magnetometer (VSM) and Raman technics. The results show that the nanoparticles have a hexagonal structure with 20 to 60 nm in size. The cytotoxic effect of the synthesized nanoparticles has been tested upon application against lung cancer cell (A549) lines. It was found that there is no cytotoxic activity at lower concentrations of 200 μg/mL. The ability of the synthesized nanoparticles for lead removal in wastewaters was tested. Results show that highest concentration of adsorbent (50 mg/L) has maximum removal efficiency (96.73 %). So, synthesized Fe₂O₃ NPs can be a good candidate to use as heavy metals cleaner from contaminated waters.     

Application of copper nanoparticles containing natural compounds in the treatment of bacterial and fungal diseases

The development of nanotechnology has generated different nanoscale-sized materials, with metal-based nanomaterials being some of the most interesting and promising. Thousands of articles in various specialized journals all over the world are dedicated to different metallic nanomaterials. Metallic nanomaterials are being widely researched, with gold-, silver-, iron-, and copper-based materials showing potential in medicine. Studies have demonstrated the effect of copper nanoparticles in medicinal herbs on the prevention, control, and treatment of microbial diseases. Experiments have examined the chemical characterization and assessment of the antioxidant, cytotoxicity, antibacterial, and antifungal activities of copper nanoparticles (Cu NPs) using the aqueous extract of Stachys lavandulifolia Vahl flower. These nanoparticles were characterized by UV–visible spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy, transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis. TEM and FE-SEM images exhibited a uniform spherical morphology and diameters of 10–25 nm for the biosynthesized nanoparticles. FT-IR results suggested polysaccharides and protein in S. lavandulifolia acted as reducing agents, reducing copper ions to Cu NPs. In vitro biological experiments indicated that Cu NPs have excellent antioxidant potential against 2,2-diphenyl-1-picrylhydrazyl, antifungal effects against Candida krusei, Candida parapsilosis, Candida guilliermondii, Candida glabrata, and Candida albicans, and antibacterial activities against Staphylococcus aureus, Enterococcus faecalis, Staphylococcus saprophyticus, Bacillus subtilis, Streptococcus pneumonia, Escherichia coli O157:H7, Salmonella typhimurium, Listeria monocytogenes, Proteus mirabilis, and Pseudomonas aeruginosa. These nanoparticles did not have cytotoxicity properties against human umbilical vein endothelial cells. These results indicate that the inclusion of S. lavandulifolia extract ameliorates the solubility of Cu NPs, which leads to a remarkable enhancement in fungicidal and bactericidal effects under in vitro conditions.     

Shape‐controlled synthesis of cerium oxide nanoparticles for efficient dye photodegradation and antibacterial activities

Herein, two‐shaped cerium oxide nanoparticles (NPs), that is, spherical and cubical, were synthesized through hydrothermal approach by tuning reaction temperatures. The morphology and structural and chemical composition of both samples were characterized by transmission electron microscopy (TEM), high‐resolution TEM (HRTEM), X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS), respectively. Both types of NPs were subjected to photodegradation of industrial dye, methylene blue, under dark, sunlight, and UV irradiation, and their recyclability and reusability were also assessed. Besides, the effect of pH, concentration of NPs, and dye on degradability was also analyzed. The cubical‐shaped NPs demonstrated superior degradation of ~70% under UV irradiation than the spherical ones (<50%). The antibacterial activities of both NPs were also examined, and cubical‐shaped NPs were found to exhibit superior antimicrobial potential (zone of inhibition [ZOI]: 25.75 ± 0.25, 18.83 ± 0.76, 15.75 ± 0.66, and 15.75 ± 0.25 mm) in comparison with the spherical ones (ZOI: 19.41 ± 0.94, 14.25 ± 0.66, 12.58 ± 1.01, and 9.91 ± 1.01 nm) for Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus respectively with reduced growth and viable count. This difference in performance may be attributed to the higher surface areas of cubical‐shaped NPs and higher content of oxygen vacancies. The results presented in this study suggest that cubical NPs are excellent candidates for treating industrial wastewater with greater reproducibility. Moreover, they can be used as active growth inhibitors against different microorganisms and thus can be extremely useful in developing medical devices and to design various antimicrobial systems.     

Antibacterial,antioxidant and photocatalytic activity of novel Rubus ellipticus leaf mediated silver nanoparticles

Nanotechnology is an emerging field of science that has significant applications in applied sciences. In this study, silver nanoparticles (SNPs) were synthesized utilizing the leaf filtrate of Rubus ellipticus. SNPs were characterized using UV–visible spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction patterns to determine their morphology and chemical composition. The surface plasmon resonance of SNPs revealed a peak at 415 nm. The synthesized SNPs were mainly spherical crystals with an average size of 21.43 nm. When compared to plant extract and positive controls (AgNO₃ and penicillin), SNPs demonstrated significant bactericidal activity against all the tested bacteria (gram-positive and gram-negative). The most effective bactericidal activity was found against Pseudomonas aeruginosa, with a minimum inhibitory concentration of 1.25 µg/mL. In addition, a dose-dependent antioxidant activity of SNPs was found against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical with an average IC50 value of 72.84 µg/mL. The photocatalytic activity of Methylene blue (MB) dye decomposition under sunlight was studied. The results showed that MB degraded by 98 % after 150 min in the sun. Overall, the findings of this study indicate that R. ellipticus biosynthesized SNPs may have bactericidal and photocatalytic effects.     

Green synthesis of silver nanoparticles by bloom forming marine microalgae Trichodesmium erythraeum and its applications in antioxidant,drug-resistant bacteria,and cytotoxicity activity

In the present study, we developed an eco-friendly method of stable silver nanoparticles (AgNPs) production using the aqueous extract of Trichodesmium erythraeum. The biosynthesized AgNPs were characterized using UV–Vis spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Energy-Dispersive X-ray (EDX), and X-ray diffraction (XRD). The results affirmed that synthesized AgNPs were crystalline in nature, cubical in shape, and the average size of T. erythraeum silver nanoparticles (TENPs) was 26.5 nm. The antioxidant potential of synthesized AgNPs (500 µg/ml) was 77.01 ± 0.17% in DPPH, 67.5 ± 0.22% in Deoxy-ribose, 52.77 ± 0.42% in ABTS and 88.12 ± 0.26% in nitric oxide radical scavenging assays. The antibacterial results showed excellent inhibition against the clinical strains (Staphylococcus aureus and Proteus mirabilis) and drug-resistant bacterial strains such as E. coli (Amikacin^R), S. aureus (Tetracycline^R) and S. pneumoniae (Penicillin^R). The maximum anti-proliferative effect of TENPs was seen using 50 µg concentration against He La and MCF-7 cell lines, and IC₅₀ values were 25.0 ± 0.50 µg/ml and 30.0 ± 0.50 µg/ml, respectively, at 24 h.     

Biosynthesis,characterization, biological and photo catalytic investigations of Elsholtzia blanda and chitosan mediated copper oxide nanoparticles

Bio synthesis of nanoparticles using plant parts has gained considerable attention, given the fact that the method is green, environment friendly, cheaper, simple and involves no hazardous substances. The present study involves the green synthesis of copper oxide nanoparticles (CuO NPs) using chitosan and the aqueous leaf extract of Elsholtzia blanda, an aromatic medicinal herb. The synthesized E.blanda-chitosan mediated copper oxide nanoparticles (CPCE) and E. blanda mediated copper oxide nanoparticles (PCE) were subjected to different characterization techniques, Ultraviolet–visible (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray Analysis (EDAX), High Resolution Transmission Electron Microscopy (HRTEM) and Selected Area Electron Diffraction (SAED). The absorbance peaks in UV–Vis spectroscopy at 286 nm and 278 nm for CPCE and PCE respectively indicated the formation of nanoparticles. TEM and SEM employed for studying the surface morphology showed rod-like and spherical morphology bearing average size of 47.71 nm for CPCE and 36.07 nm for PCE. The antibacterial activities of the prepared nanoparticles were tested against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Salmonella typhi by agar well diffusion method. The results indicate that CuO NPs possess effective antibacterial potential against all tested bacteria with a maximum zone of inhibition of 18 mm for Enterococcus faecalis. Antioxidant studies revealed the highest DPPH scavenging activity of 89% at 25 μg/mL concentration of the nanoparticles. The percentage of the photo catalytic degradation of Congo red was found to be 95% after 10 h.     

Anticancer and antibacterial potential of Rhus punjabensis and CuO nanoparticles

Abstract

The present study reports ecofriendly synthesis of CuO nanoparticles (NPs) using an extract of Rhus punjabensis as a reducing agent. NPs structural and composition analysis are evaluated by X-rays diffraction (XRD), Fourier transform infrared, Energy dispersive spectroscopy, Scanning electron microscopy, Transmission electron microscopy, and Thermal analysis. The NPs have pure single phase monoclinic geometry with spherical structure and high stability toward heat and with average particle size of about 36.6 and 31.27?nm calculated by XRD and SEM, respectively. NPs are tested for antibacterial, protein kinase (PK) inhibition, SRB cytotoxic, and NF-κB activities. Antibacterial activity is observed against B. subtilis and E. coli. Significant PK and SRB cytotoxic activity is observed with some NF-κB inhibition. NPs IC₅₀ values against HL-60 and PC-3 prostate cancer cells are 1.82?±?1.22 and 19.25?±?1.55?μg/mL. The results encourage further studies for antibacterial and anticancer drug development of NPs using animal models.     

Preparation,Antibacterial Activity,and Catalytic Application of Magnetic Graphene Oxide-Fucoidan in the Synthesis of 1,4-Dihydropyridines and Polyhydroquinolines

Polymer-coated magnetic nanoparticles are emerging as a useful tool for a variety of applications, including catalysis. In the present study, fucoidan-coated magnetic graphene oxide was synthesized using a natural sulfated polysaccharide. The prepared BaFe₁₂O₁₉@GO@Fu (Fu=fucoidan, GO=graphene oxide) was characterized using Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) analysis, vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), Raman spectroscopy, and X-ray diffraction (XRD). The catalytic proficiency of BaFe₁₂O₁₉@GO@Fu was investigated in the synthesis of 1,4-dihydropyridine and polyhydroquinoline derivatives. Excellent turnover numbers (TON) and turnover frequencies (TOF) (6330 and 25320 h⁻¹) testify to the high efficiency of the catalyst. Moreover, the antimicrobial activity of BaFe₁₂O₁₉@GO@Fu was evaluated against Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) through the Agar well diffusion method, indicating that BaFe₁₂O₁₉@GO@Fu has antibacterial activity against S. aureus.     

Chemical composition and in vitro anticancer,antimicrobial and antioxidant activities of essential oil and methanol extract from Rumex nervosus

Chemical composition, antioxidant, anticancer, and antimacrobial activities of essential oil obtained from leaves of Rumex nervosus has been evaluated here for the first time. GC/MS analysis reveals the presence of Palmitoleic Acid (28.35%) and Palmitic acid, (25. 37%) as their methyl ester as major components. The essential oil showed significant DPPH radical scavenging activity (94.907 ± 0.1089% and 94.003 ± 0.0749%) at concentration (100 and 80) μg/mL respectively. The oil showed promising activity against staph aureus, while showed weak activity against (Hela and 3T3) cell lines. The crude extract / fractions of R. nervosus (leaves) showed significant antioxidant activity at dose (100 and 80) μg/mL. Futhermore the crude showed significant activity against (MCF-7 and MDA-MB-231) cell lines with IC₅₀ (20.5138 ± 0.933 and 25.1728 ± 0.9176) μg/mL respectively, and chloroform fraction showed good activity against (MCF-7 and MDA-MB-231) cell lines with IC₅₀ (31.154 ± 0.965 and 42.269 ± 2.1045) μg/mL.     

Ecofriendly synthesis of silver nanoparticles using Kei-apple (Dovyalis caffra) fruit and their efficacy against cancer cells and clinical pathogenic microorganisms

Green fabrication has become a safe approach for producing nanoparticles. Plant-based biogenic synthesis of silver nanoparticles (AgNPs) has emerged as a possible alternative to traditional chemical production. In this paper, we provide a low-cost, green synthesis of AgNPs utilizing using Kei-apple (Dovyalis caffra) fruit extract. Ultraviolet–visible (UV–Vis) spectroscopy, Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Scanning-Electron Microscope (SEM), and Dynamic Light Scattering (DLS) analyses were used to characterize green produced AgNPs. The formation of AgNPs was shown to have a surface resonance peak of 415 nm in UV–visible spectra, and FTIR spectra verified the participation of biological molecules in Synthesis of AgNPs. The TEM revealed that the biosynthesized AgNPs were mostly spherical in form, with size range of 12–53 nm. XRD diffractogram was used to demonstrate the face cubic centre (fcc) character of AgNPs. Excellent anticancer activity of AgNPs was recorded where more than 80% of Prostate Cancer (PC-3) cell lines was inhibited by 100–150 µg/mL of AgNPs, while 38% only was recorded using AgNO₃ and 55.62% was recorded D. caffra fruit extract at 150 µg/mL. Destructions of PC-3 cell was observed as a result of exposed to AgNPs, followed by D. caffra fruit extract, while minor alterations were recorded as exposed to AgNO₃. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging using AgNPs was three fold using fruit extract at 100 µg/mL indicating good antioxidant activity. Excellent inhibitory activity of AgNPs was recorded against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus fumigatus with inhibition diameter zone 28.22 ± 0.25 mm, 23.21 ± 0.35 mm, 27.25 ± 0.03 mm, 28.40 ± 0.15 mm, 29.23 ± 0.44 mm, and 9.52 ± 0.5 mm, respectively compared with AgNO₃. D. caffra fruits considered a promising and safe source for fabrication of AgNPs with multi-biological functions.     

In vitro antimicrobial activity of extracts and compounds isolated from Cladonia uncialis

Heptane (Hep), diethyl ether (Et₂O), acetone (Me₂CO) and methanolic (MeOH) extracts, as well as ( ? )-usnic acid and squamatic acid, were obtained from thallus of Cladonia uncialis (Cladoniaceae). The antimicrobial activities of these extracts, ( ? )-usnic acid and squamatic acid, were tested against reference strains: Staphylococcus aureus, Escherichia coli and Candida albicans. In addition, Me₂CO extract was analysed against 10 strains of Methicillin-resistant S. aureus (MRSA) isolated from patients. All extracts exerted antibacterial activity against the reference strain S. aureus, comparably to chloramphenicol [minimum inhibitory concentration (MIC) = 5.0 μg/mL]. The Me₂CO extract exhibited the strongest activity against S. aureus (MIC = 0.5 μg/mL), higher than ( ? )-usnic acid, whereas squamatic acid proved inactive. The Me₂CO extract showed potent antimicrobial activity against MRSA (MIC 2.5–7.5 μg/mL). Also no activity of C. uncialis extracts against E. coli and C. albicans was observed.     

The surface modification of spherical ZnO with Ag nanoparticles: A novel agent,biogenic synthesis,catalytic and antibacterial activities

Nowadays, the industrial wastewater pollutants including toxic dyes and pathogenic microbes have caused serious environmental contaminations and human health problems. In the present study, eco-friendly and facile green synthesis of Ag modified ZnO nanoparticles (ZnO-Ag NPs) using Crataegus monogyna (C. monogyna) extract (ZnO-Ag@CME NPs) is reported. The morphology and structure of the as-biosynthesized product were characterized by field emission scanning electron microscopy (FESEM), X-Ray diffraction (XRD), differential reflectance spectroscopy (DRS), dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS) techniques. TEM and FESEM images confirmed the oval and spherical-like structure of the products with a size of 55–70 nm. The EDS analysis confirmed the presence of Zn, Ag, and O elements in the biosynthesized product. The photocatalytic results showed ZnO-Ag@CME NPs were degraded (89.8% and 75.3%) and (94.2% and 84.7%) of methyl orange (MO) and basic violet 10 (BV10), under UV and sunlight irradiations, respectively. The Ag modified ZnO nanoparticles exhibited enhanced catalytic activity towards organic pollutants, and showed better performance than the pure ZnO nanoparticles under UV and sunlight irradiations. This performance was probably due to the presence of silver nanoparticles as a plasmonic material. Antibacterial activity was performed against different bacteria. ZnO-Ag@CME NPs showed high antibacterial activity against K. pneumoniae, S. typhimurium, P. vulgaris, S. mitis, and S. faecalis with MIC values of 50, 12.5, 12.5, 12.5, and 12.45 µg/mL, respectively. All in all, the present investigation suggests a promising method to achieve high-efficiency antibacterial and catalytic performance.     

A new epipolythiodioxopiperazine with antibacterial and cytotoxic activities from the endophytic fungus Chaetomium sp. M336

A new compound 6-formamide-chetomin (1) together with chetomin (2) was isolated from solid fermentation products of the endophytic fungus Chaetomium sp. M336, which were elucidated by extensive spectroscopic analyses, including 1D and 2D NMR, and HR-ESI-MS experiments. The bioassay result showed that compound 1 had strong antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhimurium ATCC 6539 and Enterococcus faecalis with minimum inhibitory concentration (MIC) value of 0.78 μg/mL; meanwhile it exhibited strong cytotoxicity with IC₅₀ values of 21.6–27.1 nM against cell lines HeLa, SGC-7901 and A549.     

Chlorhexidine/losartan ionic pair binding and its nanoprecipitation: physico-chemical characterisation and antimicrobial activity

Chlorhexidine is a widely used, di-cationic, broad-spectrum antimicrobial agent and losartan is a well-known, anionic-specific antagonist of AT1 renin–angiotensin receptor that acts as an anti-hypertensive agent. The combination of these molecules gives a chlorhexidine di-losartanate (ClxLos₂) hydrophobic ion pair that spontaneously aggregates into nanoparticles (NPs). This work investigated the formation of ClxLos₂ NPs using the analysis of the solid state by fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy and in aqueous environment by calorimetric, zeta potential and dynamic light scattering titrations. Furthermore, to demonstrate the potential antimicrobial activity of ClxLos₂, in vitro antibacterial tests were conducted against Staphylococcus aureus (ATCC 27664), Streptococcus viridans (ATCC 11563) and Enterococcus faecalis (ATCC 14508). Based on these studies, it is proposed that ClxLos₂ could be used for controlled drug release based on ionic dissociation during dilution, thereby avoiding the use of any solid matrix.     

In vitro anticancer activity of binuclear Ru(II) complexes with Schiff bases derived from 5-substituted salicylaldehyde and 2-aminopyridine with notably low IC50 values

The binuclear Ru(II) complexes with Schiff bases derived from 5-chlorosalicyladehyde and 2-aminopyridine and its 5-substituted salicylideneimine homologues were tested in vitro against cervical carcinoma (HeLa), metastatic colorectal adenocarcinoma (SW620), lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and human lung fibroblast (WI-38) cell lines. All compounds showed strong antiproliferative activity with extremely low IC₅₀ values. The compounds expressed strong activity against gram-positive bacteria, Staphylococcus aureus and Enterococcus faecalis.     

Iron oxide superparamagnetic nanocarriers bearing amphiphilic N‐heterocyclic choline analogues as potential antimicrobial agents

Magnetic nanoparticles represent an advanced tool in biomedicine because they can be simultaneously functionalized and guided using a magnetic field. Iron oxide magnetic nanoparticles precoated with oleic acid and bearing novel antimicrobial N‐heterocyclic choline analogues, namely O‐, N‐ and O,N‐bis‐undecyl‐substituted N‐(2‐hydroxyethyl)‐1,2,3,4‐tetrahydroisoquinolinium derivatives, have been obtained as potential biomedical agents for drug delivery and antimicrobial therapy. Structural and size determinations for the novel synthesized magnetic nanosystems were carried out based upon magnetogranulometry, dynamic light‐scattering measurements and X‐ray diffraction analysis. The most expected iron oxide core diameter was 6.2–10.5 nm. The magnetization analyses showed that the particles are superparamagnetic at room temperature. Aqueous magnetic fluids of the synthesized nanoparticles were examined in vitro concerning Gram‐positive (Staphylococcus aureus MSCL 334, Bacillus cereus MSCL 330) and Gram‐negative (Escherichia coli MSCL 332, Pseudomonas aeruginosa MSCL 331, Proteus mirabilis MSCL 590) bacterial strains and fungi (Candida albicans MSCL 378, Aspergillus niger MSCL 324). It was found that the samples have magnetic properties and possess antimicrobial activity. The minimum inhibitory concentration against S. aureus for the most active magnetic fluid was determined as 16 µg ml^?1. Copyright © 2015 John Wiley & Sons, Ltd.     

Green synthesis and characterization of monodispersed silver nanoparticles obtained using oak fruit bark extract and their antibacterial activity

Green synthesis of silver nanoparticles (Ag NPs) has been achieved using oak fruit bark extract as a reducing, capping and stabilizing agent. The biosynthesized Ag NPs were characterized using various techniques. UV–visible spectrum of prepared silver colloidal solution showed absorption maximum at 433 nm. X‐ray diffraction and transmission electron microscopy analysis revealed that Ag NPs have a face‐centred cubic structure being spherical in shape with an average particle size of 20–25 nm. The toxicity of the Ag NPs was tested on bacterial species such as Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli by comparison based on diameter of inhibition zone in disc diffusion tests and minimum inhibitory concentration and minimum bactericidal concentration of NPs dispersed in liquid cultures. The antimicrobial activity of Ag NPs was greater towards Gram‐positive bacteria (S. aureus and B. subtilis) compared to Gram‐negative bacteria as determined using standard Kirby–Bauer disc diffusion assay and serial dilution. Copyright © 2016 John Wiley & Sons, Ltd.     

Biological Applications of Synthesized ZnO Nanoparticles Using Pleurotus djamor Against Mosquito Larvicidal,Histopathology, Antibacterial,Antioxidant and Anticancer Effect

The present study pertained to biosynthesis, characterization and biomedical application (larvicidal, histopathology, antibacterial, antioxidant and anticancer activity) of Zinc oxide nanoparticles (ZnONPs) from Pleurotus djamor. The synthesized NPs were characterized using spectral and microscopic analyses and further confirmed by UV–Visible spectrophotometer with apeak of 350 nm. The ZnONPs showed strong antioxidant property (DPPH, H₂O₂ and ABTS⁺ radical assay) and expressed good larval toxicity against Ae. aegypti and Cx. quinquefasciatus (IVth instar larvae) with the least LC₅₀ and LC₉₀ values (10.1, 25.6 and 14.4, 31.7 mg/l) after 24 h treatment, respectively. We noticed the morphological changes (damaged anal papillae area and the cuticle layers) in the treated larvae. For the antibacterial assay, the highest growth inhibition zone was recorded in C. diphteriae (28.6?±?0.3 mm), followed by P. fluorescens (27?±?0.5 mm) and S. aureus (26.6?±?1.5 mm). The in vitro cytotoxicity assay depicted a significant level of cytotoxic effects (LC₅₀ values 42.26 μg/ml) of ZnONPs against the A549 lung cancer cells, even at low dose. The overall findings of the study suggest that P. djamor had the ability for the biosynthesis of ZnONPs and could act as an alternative biomedical agent for future therapeutic applications in medical avenues.

     

Fluorescent Bioconjugate Based on Gold Nanoparticles for the Determination of Staphylococcus aureus

A practical method to determine Staphylococcus aureus using bioconjugated gold nanoparticles is reported. The protocol uses gold nanoparticles stabilized by tetramethylrhodamine isothiocyanate-labeled streptavidin followed by functionalization with biotinylated anti-S. aureus antibodies. The streptavidin-stabilized gold nanoparticles were obtained by titration and analyzed by ultraviolet–visible spectroscopy and transmission electron microscopy. The obtained fluorescent bioconjugate selectively linked to the surface of S. aureus in samples contaminated with the microorganism, as demonstrated by confocal micrographs. The biorecognition process was performed by mixing the fluorescent bioconjugate with the sample. Bacterial dilutions from 1 × 108 to 1 × 102 cell/ml of S. aureus were determined, obtaining sensitivity values of 1 × 105 cell/ml by photoluminescence and 1 × 102 cell/ml by bioimpedance. This methodology represents a useful bioanalytical approach for the determination of S. aureus.     

Physico-chemical characterization and anti-laryngeal cancer effects of the gold nanoparticles

Most recently, gold nanoparticles due to anticancer properties have been considered in medical science. So the aim of the study was green synthesis of gold nanoparticles using Ocimum basilicum extract and its anticancer activity. The prepared Au nanoparticles were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX), X-ray Diffraction (XRD) and UV–vis spectroscopy study. It has been established that Au nanoparticles have a spherical shape with a mean diameter from 19 to 44 nm. In the cellular and molecular part of the recent study, the treated cells with Au nanoparticles were assessed by MTT assay for 48 h about the cytotoxicity and anti-human laryngeal cancer properties on normal (HUVEC) and cancer (HEp-2, TU212, KB, UM-SCC-5, UM-SCC-11A and UM-SCC-11B) cell lines. In the antioxidant test, the IC50 of Au nanoparticles and BHT against DPPH free radicals were 228 and 208 µg/mL, respectively. The IC50 of Au nanoparticles were 174, 231, 179, 143, 230, and 216 µg/mL against HEp-2, TU212, KB, UM-SCC-5, UM-SCC-11A and UM-SCC-11B cell lines, respectively. The viability of malignant cell lines reduced dose-dependently in the presence of Au nanoparticles. It appears that the anti-cancer effect of Au nanoparticles e to their antioxidant effects.