Antibacterial Activity Of ZnO NPs Research Articles

Antibacterial Activity of Zinc Oxide Nanoparticles Synthesized by Green Eichhornia Crassipes Extract Method

Purpose: Zinc Oxide Nanoparticle (ZnO NPs) production has become more common because of the benefits of the green strategy, which include its ease of use, environmental friendliness, and cheap operating costs. In order to accomplish the goal of green chemistry, the green synthesis process also uses safe solvents like water and ethanol. ZnO NPs are among the metal oxide-NPs used in antibacterial and bioremediation applications. Materials and Methods: Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared spectroscopy (FT-IR), X-Ray Diffractometer (XRD), and Field Emission Scanning Electron Microscopy (FESEM) were used to analyze the green-produced ZnO NPs. Results: ZnO nanoparticles have an average size of 22.89 nm, which is corroborated by FESEM pictures, indicating that the particles are tiny. The excellent purity of ZnO NPs has been confirmed by EDX data. The antibacterial activity of ZnO NPs was assessed against a few dangerous pathogens. Zinc oxide nanoparticles were shown to have an interesting antibacterial action against both gram-positive and gram-negative bacteria at micromolar concentrations because they exhibit the maximum diameter of inhibition zone at concentrations 100 mg/ml of S. aureus, E. coli, K. pneumonia, Acintobacret spp, S. fecalis reaching (27,19,18,17, and 14) mm, respectively while S. pneumonia were resistant.The ZnO NPs recorded at a concentration of 12.5 mg/ml lowest areas of the inhibition zone against the same isolates reaching (16, 11, 11, 12, and 10) mm while S. pneumonia were resistant, respectively, as well. Conclusion: ZnO NPs, since they have excellent antibacterial properties, and are biocompatible, they will open up a new line of inquiry for antibacterial agent research because they are stable, nontoxic, and harmless.

Sustainable synthesis of zinc oxide nanoparticles using Piper betle petiole leaf extract: Antibacterial, antioxidant, and cytotoxic potential

The present study used Piper betle petiole leaf extract as an efficient reducing agent to produce zinc oxide nanoparticles (ZnO NPs). The change in the color of reaction mixture from brown to white indicates the formation of ZnO NPs, which is also noticed in UV–Visible spectral analysis (peak at 320 nm). Investigations using X-ray diffraction (XRD) revealed that the particles were crystalline. Additionally, scanning electron microscopy (SEM), Energy Dispersive X-ray diffraction (EDAX), dynamic light scattering (DLS), and Fourier transform infrared (FTIR) techniques were used to understand the structural, and elemental aspects of the as-prepared ZnO NPs. The antibacterial activity of ZnO NPs was assessed using the disc diffusion approach method against clinical strains of Escherichia coli, Pseudomonas fluorescence, Micrococcus luteus, and Bacillus subtilis. The zone of inhibition and minimum inhibitory indices (MIC) were used in this process. The as-prepared ZnO NPs showed strong antibacterial effects. In addition, the anticancer efficacy of the material was tested against MDA-MB-231 breast cancer cell lines, the results of which revealed that the tested ZnO NPs was potent in inhibiting the growth of the cancer cells. The mechanistic evaluation of such an activity carried out using in silico methods suggested that the anti-breast cancer activity of L-ZnONPs was mediated by human HER2 kinase domain. This suggests that preparation of ZnO NPs from plant sources can be an excellent method of producing biomedical goods that are both environmentally friendly and versatile.

Synthesis of organic-inorganic hybrid nanocomposites modified by catalase-like catalytic sites for the controlling of kiwifruit bacterial canker.

Kiwifruit bacterial canker, caused by Pseudomonas syringae pv. Actinidiae (Psa), is one of the most important diseases in kiwifruit, creating huge economic losses to kiwifruit-growing countries around the world. Metal-based nanomaterials offer a promising alternative strategy to combat plant diseases induced by bacterial infection. However, it is still challenging to design highly active nanomaterials for controlling kiwifruit bacterial canker. Here, a novel multifunctional nanocomposite (ZnO@PDA-Mn) is designed that integrates the antibacterial activity of zinc oxide nanoparticles (ZnO NPs) with the plant reactive oxygen species scavenging ability of catalase (CAT) enzyme-like active sites through introducing manganese modified polydopamine (PDA) coating. The results reveal that ZnO@PDA-Mn nanocomposites can efficiently catalyze the conversion of H2O2 to O2 and H2O to achieve excellent CAT-like activity. In vitro experiments demonstrate that ZnO@PDA-Mn nanocomposites maintain the antibacterial activity of ZnO NPs and induce significant damage to bacterial cell membranes. Importantly, ZnO@PDA-Mn nanocomposites display outstanding curative and protective efficiencies of 47.7% and 53.8% at a dose of 200 μg mL-1 against Psa in vivo, which are superior to those of zinc thiozole (20.6% and 8.8%) and ZnO (38.7% and 33.8%). The nanocomposites offer improved in vivo control efficacy through direct bactericidal effects and decreasing oxidative damage in plants induced by bacterial infection. Our research underscores the potential of nanocomposites containing CAT-like active sites in plant protection, offering a promising strategy for sustainable disease management in agriculture.

Enhancement and Evolution of Anti-Bacterial activity of ZnO NPs by doping with Silver

In recent decades nanotechnology received a great importance because of its multidisciplinary role in various fields. Nano ZnO is one of most emerging nano metal oxide has been using in various applications such as fire retard, anti-microbe and anti-wrinkle etc. and showing good performance when doped with Silver. The Pure and Ag doped nano ZnO synthesized were subjected to characterization to know the morphology and physical properties. FTIR analysis was employed for the identification of functional group, X-Ray Diffraction is to identify the crystalline structure, SEM-EDX Analysis employed to know the morphological structure and size of the synthesized nanoparticles and elemental confirmation, and Transmission Electron Microscopy to determine the particle size and shape of synthesized nano particles. The synthesized Pure and Ag doped nano ZnO was screened for their anti-bacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis by disc diffusion method.

Green synthesis of zinc oxide nanoparticles using novel bacterium strain (Bacillus subtilis NH1-8) and their in vitro antibacterial and antibiofilm activities against Salmonellatyphimurium

Zinc oxide nanoparticles (ZnO NPs) are used in a range of applications, including food packaging, preservation, and storage. In the current investigation, extracellular green synthesis of ZnO NPs through an simple, eco-friendly, and rapid approach using a novel bacterial strain (Bacillus subtilis NH1-8) was studied. To assess the morphological, optical, and structural properties of ZnO NPs, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, and X-ray diffraction (XRD) techniques were carried out. In addition, disk diffusion, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC) methods were performed to determine the antibacterial activity of ZnO NPs. The average size of biosynthesized ZnO NPs was 39 nm, exhibiting semi-spherical, which was confirmed by TEM analyses. The UV–vis spectroscopy exhibited the absorption peak at 200–800 nm. The ZnO NPs have shown effective antimicrobial and antibiofilm activities against S. typhimurium. Thus, biosynthesized ZnO NPs could be exploited as a breakthrough technology in the surface coating of food containers and cans to minimize contamination by S. typhimurium.

Antibacterial activity of biosynthesized zinc oxide nanoparticles using Kombucha extract

Antibacterial resistance is a growing global vital medical problem when the innovation and development of new antibiotics are dwindling. Different nanomaterials were synthesized and developed as safe and effective alternative antimicrobial agents. The current study highlights the effect of the antibacterial activity of newly biosynthesized zinc oxide nanoparticles (ZnO NPs) obtained from Kombucha extract. Production of ZnO NPs was optimized and the synthesized nanoparticles were characterized using UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Zeta potential and transmission electron microscope (TEM) analysis. The optimum conditions for ZnO NPs production were at temperature 30 °C, pH 9 and 25 mM of Zn(NO3)2.6H2O. The ZnO NPs biosynthesis was detected in the extract within 24 h. at 35 °C in dark conditions. The XRD pattern displayed 100, 101, 110, and 103 crystal planes. FTIR spectrum showed bands of 1° and 2° amines at 2922.6 cm−1 and a stretching vibration band of vinyl at 1657.5 cm−1. In addition, the results confirmed the positive charge (19 ± 3 mV) and crystalline nature of spherical-shaped ZnO NPs with an average size of 23 ± 1.5 nm. The antibacterial activity of ZnO NPs was tested against different American-type culture collection strains. ZnO NPs exhibited minimum inhibition concentration (MIC) values of 25 µg/ml against Escherichia coli ATCC25922, 30 µg/ml against Staphylococcus aureus ATCC25923 and Pseudomonas aeruginosa ATCC27853, 35 µg/ml against Serratia liquefaciens OQ071699.1 and S. saprophyticus OQ071703.1 and 40 µg/ml against Lysinibacillus fusiformis OQ071701.1 and Klebsiella pneumoniae ATCC33495. Ultrastructure TEM study of the treated bacteria by MIC of ZnO NPs confirmed their highly toxic action on the bacterial cell wall, resulting in bacterial cell membrane rupture. Treated bacteria appeared as extensively damaged cells with the formation of vacuoles and lipids. The provided approach of ZnO NPs in combination with Kombucha SCOBY has a promising future in overcoming bacterial resistance problems in place of using antibiotics.

Centrifugally spun PVP/ZnO composite fibers with different surfactants and their use as antibacterial agents

AbstractPolyvinylpyrrolidone (PVP) fibers embedded with Zinc Oxide nanoparticles (ZnO NPs) were prepared by the centrifugal spinning of aqueous PVP solutions and ZnO NPs. The ZnO NPs were synthesized and coated with either cetyltrimethylammonium bromide or hexadecyltrimethylammonium bromide. The structure and morphology of the nanocomposite fibers were studied using scanning electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, Fourier transformed infrared spectroscopy and Thermogravimetric analysis. The effect of surfactant coating on the antibacterial activity of ZnO NPs and PVP/ZnO nanocomposite fibers against Escherichia coli (E. coli) and Bacillus megaterium (B. megaterium) bacteria was systematically investigated. The present study indicated that coating the ZnO NPs with surfactants resulted in large and uniform inhibition of bacterial growth.

Green synthesised zinc oxide nanoparticles reveal potent in vivo and in vitro antibacterial efficacy against Proteus mirabilis isolates

Currently, the spread of antimicrobial resistance dissemination is expanding at an accelerated rate. Therefore, numerous researchers haveinvestigatedalternative treatments in an effort to combat this significant issue. This study evaluated the antibacterial properties of zinc-oxide nanoparticles (ZnO NPs) synthesised by Cycas circinalis against Proteus mirabilis clinical isolates. HPLC was utilised for the identification and quantification of C. circinalis metabolites. The green synthesis of ZnO NPs has been confirmed using UV–VIS spectrophotometry. The Fourier transform infrared spectrum of metal oxide bonds has been compared to the free C. circinalis extract spectrum. The crystalline structure and elemental composition were investigated using X-ray diffraction and Energy-dispersive X-ray techniques. The morphology of nanoparticles was assessed by scanning and transmission electron microscopies, which revealed an average particle size of 26.83 ± 5.87 nm with spherical outlines. The dynamic light scattering technique confirms the optimum stability of ZnO NPs with a zeta potential value equal to 26.4 ± 0.49 mV. Using agar well diffusion and broth microdilution methods, we elucidated the antibacterial activity of ZnO NPs in vitro. MIC values for ZnO NPs ranged from 32 to 128 µg/mL. In 50% of the tested isolates, the membrane integrity was compromised by ZnO nanoparticles. In addition, we assessed the in vivo antibacterial capacity of ZnO NPs by a systemic infection induction using P. mirabilis bacteria in mice. The bacterial count in the kidney tissues was determined, and a significant decrease in CFU/g tissues was observed. The survival rate was evaluated, and the ZnO NPs treated group had higher survival rates. The histopathological studies demonstrated that kidney tissues treated with ZnO NPs had normal structures and architecture. Moreover, the immunohistochemical examinations and ELISA revealed that ZnO NPs substantially decreased the proinflammatory mediators NF-kβ, COX-2, TNF-α, IL-6, and IL-1β in kidney tissues. In conclusion, the results of this study suggest that ZnO NPs are effective against bacterial infections caused by P. mirabilis.

Trichoderma-Mediated ZnO Nanoparticles and Their Antibiofilm and Antibacterial Activities

Antimicrobial resistance is a major global health concern and one of the gravest challenges to humanity today. Antibiotic resistance has been acquired by certain bacterial strains. As a result, new antibacterial drugs are urgently required to combat resistant microorganisms. Species of Trichoderma are known to produce a wide range of enzymes and secondary metabolites that can be exploited for the synthesis of nanoparticles. In the present study, Trichoderma asperellum was isolated from rhizosphere soil and used for the biosynthesis of ZnO NPs. To examine the antibacterial activity of ZnO NPs against human pathogens, Escherichia coli and Staphylococcus aureus were used. The obtained antibacterial results show that the biosynthesized ZnO NPs were efficient antibacterial agents against the pathogens E. coli and S. aureus, with an inhibition zone of 3-9 mm. The ZnO NPs were also effective in the prevention of S. aureus biofilm formation and adherence. The current work shows that the MIC dosages of ZnO NPs (25, 50, and 75 μg/mL) have effective antibacterial activity and antibiofilm action against S. aureus. As a result, ZnO NPs can be used as a part of combination therapy for drug-resistant S. aureus infections, where biofilm development is critical for disease progression.

OPTIMIZATION SYNTHESIS OF ZINC OXIDE NANOPARTICLES USING FACTORIAL DESIGN AND ITS ANTIBACTERIAL ACTIVITY

Due to their chemical stability, potent antibacterial activity, and comparatively low hazardous profile, inorganic metal oxides may be used as efficient antibacterial. Zinc oxide nanoparticles (ZnO NPs) significantly slow down the growth of various bacteria. This study aimed to determine the effect and interaction of pH, calcination temperature, and pectin (capping agent) on the synthesis and antibacterial activity of ZnO NPs. The synthesis was carried out by the precipitation method. Synthesis optimization using Design Expert software (factorial design) with parameters including yield, particle size, polydispersity index, zeta potential, particle shape, and inhibition zone of bacteria (P.acnes, S.aureus, and S.epidermidis). This study proves that the synthesis of ZnO NPs is influenced by pH, calcination temperature, and pectin. Various characteristics of the synthesized ZnO NPs have different antibacterial activity. The results of Design Expert analysis with 3 g of precursor obtained the optimum combination at pH 8.8, calcination temperature of 600°C, and pectin 0.76%.

A novel green preparation of zinc oxide nanoparticles with Hibiscus sabdariffa L.: photocatalytic performance, evaluation of antioxidant and antibacterial activity

ABSTRACT This study investigates the eco-friendly synthesis of zinc oxide nanoparticles (ZnO NPs) utilizing an aqueous solution of Hibiscus sabdariffa L. flower extract, which is acts as reducing agent as well as capping agent. The Fourier transform infrared spectroscopy (FTIR) results revealed the presence of flavonoids and phenols in the plant extract, indicating that they were the major agents capable of reducing zinc nitrate salt. According to our x-ray diffraction (XRD) results, ZnO-NPs exhibit a particular phase wurtzite structure. The ZnO-NPs are spherical in shape and have an average size of 15 nm, according to the measurements of electron microscope (SEM) and transmission electron microscope (TEM) measurements. Energy dispersion (EDX) analysis demonstrates that the NPs are mainly composed of zinc and oxygen. The zeta potential of these nanoparticles shows that they are very stable. The antibacterial activity of ZnO-NPs was tested using agar dilutions with a variety of gram-positive and gram-negative microorganisms. According to the research results, ZnO-NPs can be established as an extremely specific antibacterial agent for a wide variety of organisms to prevent bacterial growth. Furthermore, the antioxidant properties of ZnO-NPs were determined using the 2,2 diphenyl-1-picrylhydrazyl hydrate (DPPH) radical scavenging approach, and the IC50 value of 38 μg/mL was measured for ZnO-NPs. Furthermore, the biosynthesized ZnO-NPs showed significant catalytic performance of methyl orange (MO) under UV irradiation. Overall, ZnO-NPs in their produced state have excellent potential in biomedical and wastewater treatment applications. Radical scavengers were used to evaluate the role of radicals in the reaction mechanism.

Physiotherapeutic Protocol and ZnO Nanoparticles: A Combined Novel Treatment Program against Bacterial Pyomyositis.

Simple SummaryBacterial infections are among the widely disturbing diseases and leading cause of mortality around the world. Some bacterial strains can invade the skeletal muscles by producing proteolytic enzymes, causing pyomyositis. The aim of the present investigation was to evaluate ZnO nanoparticles (ZnO-NPs) as an effective treatment for bacterial pyomyositis in combination with a physiotherapeutic program (consisting of swimming and a low-level laser treatment (LLLT)). Results revealed the significant and synergistic effect of both ZnO-NPs along with the physiotherapeutic program in enhancing the histoarchitecture, immunity and hemostasis, and some vital physiological biomarkers. This emphasizes the urgency of spreading more awareness about the importance of the combined effect between nanotechnology and physiotherapeutic programs in muscle regeneration after pyomyositis caused by virulent infection with proteolytic bacteria.Myositis tropicans or pyomyositis is a muscle inflammation resulting from a bacterial infection of skeletal muscle (commonly caused by Staphylococcus aureus) that usually leads to hematogenous muscle seeding. The present study was designed to estimate the role of ZnO-NPs and a physiotherapeutic program in the management of induced biceps femoris atrophy in rats through histological, biochemical, and radiological examinations at different time intervals. At the beginning, several bacterial strains were evaluated through a proteolytic enzyme activity assay and the highest activity was recorded with the Staphylococcus aureus strain. ZnO-NPs were synthesized with the arc discharge method with an average size of 19.4 nm. The antibacterial activity of ZnO-NPs was investigated and it was revealed that the prepared ZnO-NPs showed a minimum inhibitory concentration of 8 µg/mL against the tested bacterium. The cytotoxicity of the prepared ZnO-NPs was tested in C2C12 myoblast cells, and it was elaborated that CC50 was 344.16 µg/mL. Biceps femoris pyomyositis was induced with a potent strain (Staphylococcus aureus); then, a physiotherapeutic program combined with the prepared ZnO-NPs treatment protocol was applied and evaluated. The combined program claimed antibacterial properties, preventing muscle atrophy, and resulted in the most comparable value of muscle mass.

Experimental investigations on effects of ZnO NPS and annona muricata extract for in vitro and in vivo antibacterial activity

ZnO NPs and annona muricata extract was used as antibacterial against some pathogenic bacteria isolated from different sources of infections. Furthermore, this work demonstrated the effect of oral dosage of ZnO NPs and annona muricata extract on the infected experimental animals. Moreover, the results showed the sensitivity of studied bacteria is variance against ZnO NPs and annona muricata extract and this sensitivity increase with increasing the concentration of both ZnO NPs and annona muricata extract. The in vitro study included using five bacterial species (S.aureus, S.epidermidis, P.aeruginosa, Proteus sp. and E.coli) and two in vivo studies (S.aureus and E.coli) which were given orally to experimental animals to verify the antibacterial activity of ZnO NPs and annona muricata extract against infections resulting from these pathogenic bacteria. The results were showed the effectiveness of ZnO NPs and annona muricata extract and no negative effect to be used as antibacterial agents. Therefore, this study can be considered important in the field of medicine, because the results of healing are very effective for these two substances.

Biogenic ZnO Nanoparticles Synthesized from Origanum vulgare Abrogates Quorum Sensing and Biofilm Formation in Opportunistic Pathogen Chromobacterium violaceum.

This study presents an inexpensive, eco-friendly, and simple green synthesis of ZnO nanoparticles using Origanum vulgare extract. These nanoparticles are non-hazardous, environmentally friendly, and cheaper than other methods of biosynthesis. Ongoing research determines the role of phytochemicals in the fabrication and biosynthesis of ZnO NPs and their role in antibacterial activity and biomedical applications. Characterizations by fourier transform infrared spectroscopy (FTIR), diffuse reflectance UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) determine the successful biosynthesis of ZnO NPs. Meanwhile, TEM and X-ray diffraction studies approximated the spherical morphology and crystalline nature of biosynthesized ZnO NPs of nano size in the range of 20–30 nm. The global increase in drug resistance necessitates the search for new drugs with different mechanisms of action. Quorum sensing (QS), a cell-to-cell communication, has gained attention as an emerging drug target. It controls numerous biochemical processes in bacteria, which are essential for their survival and pathogenicity. The potential of nanomedicines has also been tested to synthesize new antibiotics to tackle drug resistance. ZnO NPs were explored for their antibacterial, antiquorum sensing, and antibiofilm activities with a bioreporter strain of Chromobacterium violaceum. Susceptibility testing results indicated the potential antibacterial activity of ZnO NPs with a minimum inhibitory concentration (MIC) of 4 µg/mL and minimum bactericidal concentration (MBC) of 16 µg/mL. Antiquorum-sensing assays revealed that these nanoparticles inhibit quorum sensing with minimum antiquorum sensing activity (MQSIC) of 1 µg/mL, without causing any bacterial growth inhibition. In addition, ZnO NPs inhibit biofilm formation at inhibitory and higher concentrations. RT-qPCR results supported the downregulation of the quorum sensing genes when C. violaceum was treated with ZnO NPs. The outcomes of this study are promising with regard to the biofilm and quorum sensing, emphasizing the potential applications of ZnO NPs against bacterial communication and biofilm formation.

Antibacterial Potential of Biosynthesized Zinc Oxide Nanoparticles against Poultry-Associated Foodborne Pathogens: An In Vitro Study.

Simple SummaryThe overuse of antibiotics in the poultry industry has led to the emergence of multidrug-resistant microorganisms. Thus, there is a need to find an alternative to conventional antibiotics. Recently, zinc oxide nanoparticles (ZnO NPs) have gained much attention due to their excellent antibacterial activity. In addition, ZnO NPs is an essential trace mineral in poultry diets. In this sense, incorporating ZnO NPs into poultry can promote growth and performance while serving as an alternative antibacterial agent to control diseases. Therefore, this study aimed to assess the in vitro antibacterial activity and antibacterial mechanisms of ZnO NPs against poultry-associated foodborne pathogens (Salmonella spp., Escherichia coli, and Staphylococcus aureus). The obtained findings demonstrated effective antibacterial actions against the tested microorganisms. The nanotechnology approach could represent a new tool for combating pathogens in the poultry industry.Since the emergence of multidrug-resistant bacteria in the poultry industry is currently a serious threat, there is an urgent need to develop a more efficient and alternative antibacterial substance. Zinc oxide nanoparticles (ZnO NPs) have exhibited antibacterial efficacy against a wide range of microorganisms. Although the in vitro antibacterial activity of ZnO NPs has been studied, little is known about the antibacterial mechanisms of ZnO NPs against poultry-associated foodborne pathogens. In the present study, ZnO NPs were successfully synthesized using Lactobacillus plantarum TA4, characterized, and their antibacterial potential against common avian pathogens (Salmonella spp., Escherichia coli, and Staphylococcus aureus) was investigated. Confirmation of ZnO NPs by UV-Visual spectroscopy showed an absorption band center at 360 nm. Morphologically, the synthesized ZnO NPs were oval with an average particle size of 29.7 nm. Based on the dissolution study of Zn2+, ZnO NPs released more ions than their bulk counterparts. Results from the agar well diffusion assay indicated that ZnO NPs effectively inhibited the growth of the three poultry-associated foodborne pathogens. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed using various concentrations of ZnO NPs, which resulted in excellent antibacterial activity as compared to their bulkier counterparts. S. aureus was more susceptible to ZnO NPs compared to the other tested bacteria. Furthermore, the ZnO NPs demonstrated substantial biofilm inhibition and eradication. The formation of reactive oxygen species (ROS) and cellular material leakage was quantified to determine the underlying antibacterial mechanisms, whereas a scanning electron microscope (SEM) was used to examine the morphological changes of tested bacteria treated with ZnO NPs. The findings suggested that ROS-induced oxidative stress caused membrane damage and bacterial cell death. Overall, the results demonstrated that ZnO NPs could be developed as an alternative antibiotic in poultry production and revealed new possibilities in combating pathogenic microorganisms.

Optimized Synthesis of Biopolymer-Based Zinc Oxide Nanoparticles and Evaluation of Their Antibacterial Activity

Owing to their unique properties, zinc oxide nanoparticles (ZnO NPs) have a broad range of exciting applications. However, the problem of nanoparticles aggregation remains challenging. So, biopolymers of polysaccharides can provide green and promising stabilizers as alternatives to the current toxic chemical stabilizers during ZnO NPs synthesis. The main idea in this investigation is to tune ZnO NPs with an appropriate texture, shape, and size for antibacterial application. So, this work compares the use of three different eco-friendly stabilizers namely starch, carboxymethyl cellulose, and hydroxyethyl cellulose as alternatives capping agents in the fabrication of ZnO NPs at various times. The optimized ZnO NPs sample was obtained using starch as the optimum stabilizer at reaction conditions of 0.5 h, room temperature (25 °C), 1:2) MZn:MNaOH) ratio and 1% (w/v) starch concentration. The optical, texture, and structural properties of prepared ZnO NPs were characterized by UV–Vis, DLS, zeta potential, FT-IR, and TEM techniques. ZnO NPs showed a mean zeta potential of −21.6 mV, explaining that they are moderately stable. The analysis by TEM confirmed that the NPs were spherical and have an average size of 23 nm. The antibacterial properties of ZnO NPs against Gram-positive (Bacillus subtilis and Staphylococcus epidermidis) and Gram-negative (Enterobacter cloacae and Escherichia coli) bacteria were evaluated based on the zone of inhibition (ZOI) values expressed in mm. The results showed promising performances for their antibacterial activity against the tested bacteria which indicated a strong antibacterial activity of ZnO NPs against B. subtilis, S. epidermidis, and E. cloacae with ZOI values of 17, 14 and 16 mm, respectively, and it showed moderate activity against E. coli (ZOI = 10 mm). The synthesis of biopolymer stabilized ZnO NPs by this approach could be eco-friendly and cost-effective and synthesized ZnO NPs can serve as promising antibacterial agents.

Facile synthesis of Te-doped ZnO nanoparticles and their morphology-dependent antibacterial studies

The present study aims to carry out synthesis and characterization of Te-doped ZnO nanoparticles using an easy, low cost and solution-free thermo-mechanical method. The structural, morphological, optoelectronic characteristics of the as-prepared Te-doped ZnO NPs were analyzed by several techniques. From the FE-SEM studies, both pristine and Te-doped ZnO showed tube-shaped morphology when ground for 60 min. Remarkably, different grinding times caused the change in the shape of spherical ZnO NPs to tube-like ZnO. SEM images illustrate that spherical-like and hexagonal tube-like ZnO were prepared with grinding times 30 min and 60 min, respectively. XRD of Te-doped ZnO NPs (0.5wt%, 3wt%, 5wt%) revealed crystallite size of 10–20 nm. XPS results showed evidence for the binding energies of ZnO and Te. Disk diffusion assay showed that Te-doped ZnO NPs demonstrated good antibacterial activity against E. coli DH5α cells compared with pristine ZnO NPs. The mechanism of antibacterial activity of ZnO NPs was due to the generation of reactive oxygen species (ROS), causing lipid peroxidation of the bacterial cell wall and resulting in the leakage of cellular contents and cell death. The photoexcited electrons were trapped by the oxygen vacancies and prevented the interaction between oxygen available on the exterior of the ZnO NPs and photoexcited electrons. This results in reducing the amount of ROS generation and subsequently lower antibacterial activity.

Optimization delivery of 5-fluorouracil onto different morphologies of ZnO NPs: release and functional effects against colorectal cancer cell lines

The excellent antimicrobial and anticancer efficacy of zinc oxide nanoparticles (ZnO NPs) with strong adsorption capability, low toxicity, low-cost and biocompatibility have spun these nanomaterials into one of the drug delivery systems. Herein, we prepared ZnO NPs with different morphologies and particle size using different methods. ZnO NPs were characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, dynamic light scattering, zeta potential analyzer, scanning electron microscopy and transmission electron microscopy. Spheres with different average diameter ranged from 27 to 94.3 nm, flowers like shape with an average diameter of 250 nm, rod like shape with an average diameter of 92 nm, average length of 337 nm and a semispherical nanosheets with an average diameter of 49 nm were obtained. The nanoparticles were loaded by 5-fluorouracil as anticancer drug model. Adsorption capacity is influenced by the morphology and the size of nanoparticles. Kinetics using pseudo-first-order, pseudo-second-order and intra particle diffusion models was studied. Adsorption isotherms was explored using Langmuir, Freundlich and Temkin isotherm equations. Antibacterial activity of ZnO NPs onto gram-negative and gram-positive bacteria was studied by using disk diffusion agar method. The release of 5-fluorouracil from loaded ZnO NPs was studied at different pH media (2, 7.4) by using UV–visible spectrophotometer. 5-fluorouracil loaded ZnO NPs were examined against colon cancer (HCT) cell line. The spheres and flower-loaded drug showed higher efficacy than pure drug against colon cancer cell line. The results suggest that changing ZnO NPs morphology and particle size will affect antibacterial, anticancer activity, loading capacity of 5-fluorouracil and release profile.

Investigation of antibacterial and photocatalytic efficiency of green ZnO nanoparticles that synthesized with Celosia Cristata flower extract.

Increasing interest in green chemistry has led scientists to an environmentally friendly nanoparticle synthesis approach that has many advantages, such as simple, affordable and versatility for a wide range of commercial production. In this study, green synthesis of zinc oxide nanoparticles (ZnO NPs), which is widely researched in the field of nanotechnology, was performed under different conditions (volume ratio of CC flower extract to Zn(CH3COO)2 solution, time, pH and temperature) using the aqueous extract of Amarant (Celosia cristata L., CC, cockscome) plant flowers. Produced ZnO NPs were characterized by UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) analysis. The characteristic absorption peak seen at λmax: 364 nm in the UV-Vis absorption spectrum and the band seen at 381 cm-1 in the FTIR spectrum indicate that ZnO NPs were synthesized. TEM image also confirmed the formation of nanoparticles. The average size of nanoparticles is approximately 22-27 nm and the shape of the ZnO NPs as nearly spherical. The effect of different calcination temperatures (100, 200, 300, 400, and 500 °C) on the size of ZnO NPs was investigated and it was observed that the particle size decreased as the calcination temperature increased. ZnO NPs were also used as photo catalyst for removal of basic yellow28 (BY28) and basic violet39 (BV39) dyestuffs which are used in textile industry and ecologically toxic. The decolorization efficiency was found 95%-100% and 62% respectively when the BV39 and BY28 dyestuffs were exposed to UV light for 160 min. Antibacterial activity of ZnO NPs produced with different amounts of CC flower extract and calcined at different temperatures (100, 200, 300, 400, and 500 °C) was investigated using modified disc diffusion method. Produced ZnO NPs displayed antibacterial activity against Staphylococcus aureus and Escherichia coli bacterial strains and were more effective against gram-positive pathogens. The findings displayed that the antibacterial activity of ZnO NPs is related to the particle size. This new environmentally friendly synthesis approach is a suitable technique for large-scale commercial production and can be considered as an alternative to chemical methods.

Boswellia sacra leaf extract mediated biosynthesis of ZnO nanoparticles: Characterization, photocatalytic and antibacterial activity

The Boswellia sacra or Olibanum tree has unique herbal properties in the Burseraceae family and has already been considered a versatile material in traditional Arabic medicine. Zinc oxide nanoparticles (ZnO NPs) were synthesized using B. sacra aqueous leaf extract as a mediator in the present study. As a critical reducing and stabilizing agent for ZnO NPs, B. sacra aqueous extract with reducing polysaccharides and phytochemicals have been used. UV-visible spectroscopy has preliminarily confirmed the formation of ZnO NPs. FTIR, XRD, and SEM analyses were used to classify the photosynthesized nanoparticles. The functional group present in the nanoparticles was analyzed using FTIR. X-ray diffraction has been used to validate the particles’ crystalline existence. SEM technique determined the nanoparticles’ morphology and crystalline phase of the nanoparticles. The enhanced photocatalytic activity for methylene blue as model pollutant dye under solar irradiation was 84% in 100 minutes. The antibacterial activity of ZnO NPs was tested using the agar diffusion technique against Staphylococcus aureus, Bacillus subtilis (gram-positive), and Escherichia coli Pseudomonas aeruginosa (gram-negative) species. ZnO NPs synthesized using B. sacra leaf extract exhibited promising results against Gram-positive and Gram-negative bacterial strains with a maximum inhibition zone of 15 mm and 14 mm, respectively. In conclusion, the results indicated that the protocol is quick, fast, one-step, eco-friendly, non-toxic, and alternative to physical/chemical traditional methods.