Zinc Oxide Nanoparticles Suspensions Research Articles

Brassica oleracea L. (Acephala Group) based zinc oxide nanoparticles and their efficacy as antibacterial agent.

Zinc oxide nanoparticles were synthesized from the leaf extract of Brassica oleracea L. Acephala group (collard green) followed by their characterization using Scanning Electron Microscope (SEM), and Energy Dispersive X-ray (EDX). The antibacterial properties of zinc nanoparticles were tested against Gram-negative bacteria, Pseudomonas aeruginosa (ATCC ® 9027™), Escherichia coli (ATCC ® 8739™), Klebsiella pneumoniae (ATCC® BAA-1705™) and Gram-positive bacteria, Staphylococcus aureus (ATCC ® 6538™) and Listeria monocytogenes (ATCC ® 13932™), at four different concentrations (50.00 µg/ml, 100.00 µg/ml, 500.00 µg/ml and 1 mg/ml) of zinc oxide nanoparticles suspension. Results revealed that the synthesized nanoparticles exhibit strong antibacterial effects against Pseudomonas aeruginosa, Listeria monocytogenes, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli at 500.00 µg/ml-1 mg/ml concentrations. An increase in efficacy of nanoparticles with the decrease of their size was also evident. This is a first ever report on Brassica oleracea, L. based nanoparticles which demonstrates that 500.00 µg-1 mg/ml conc. of zinc oxide nanoparticles have antibacterial activity against both Gram -ve and Gram +ve bacteria and have the potential to be considered as an antibacterial agent in future.

Observing zinc oxide nanoparticles suspension stability in various media by using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS)

Zinc oxide (ZnO) nanoparticles are widely used in industry due to their ability to absorb UV light and antibacterial property. The total surface area of ZnO nanoparticles affects its properties and applications. Therefore, the size and stability control of ZnO nanoparticles is very important. We explored the ability of single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) in combination with settling process to analyze ZnO nanoparticles suspended in various media, by which the method allows to detect specific nanoparticles at very low concentration. The settling experiment of ZnO nanoparticles suspended in various media, including deionized water, non-ionic, cationic and anionic surfactants, was carried out to study size, stability and dispersion. The SP-ICP-MS along with settling experiment was set up by suspending different sizes of ZnO nanoparticles in deionized water, Triton X-100, cetyltrimethylammonium bromide and sodium dodecyl sulfate, followed by collecting the sample at various times and vertical distances. Then, the collected samples were diluted and analyzed by SP-ICP-MS to obtain the information on particle size distribution and the particle number concentration. The size and morphology of the ZnO nanoparticles were observed by transmission electron microscopy technique and zeta potential values of particles suspension were measured. The total concentrations of Zn in the suspension were also analyzed by conventional mode ICP-MS to compare with single particle mode ICP-MS. The information obtained in this work allows us to assess the stability of ZnO nanoparticles in various media and shows that the newly developed approach based on SP-ICP-MS with settling experiment can be used as an alternative characterization tool to evaluate the stability of nanoparticles.

Zinc oxide nanoparticles induce acute lung injury via oxidative stress-mediated mitochondrial damage and NLRP3 inflammasome activation: In vitro and in vivo studies

The widespread application of zinc oxide nanoparticles (ZnO-NPs) brings convenience to our lives while also renders threats to public health and ecological environment. The lung has been recognized as a primary target of ZnO-NPs, however, the detrimental effects and mechanism of ZnO-NPs on the respiratory system have not been thoroughly characterized so far. To investigate the effect of ZnO-NPs on acute lung injury (ALI), Sprague Dawley rats were intratracheally instilled with ZnO-NPs suspension at doses of 1, 2, and 4 mg/kg/day for 3 consecutive days. Our study revealed that ZnO-NPs induced ALI in rats characterized by increased airway resistance, excessive inflammatory response and lung histological damage. In addition, we identified several molecular biomarkers related to the potential mechanism of ZnO-NP-induced ALI, including oxidative stress, mitochondrial damage, and NLRP3 inflammasome activation. The results of in vitro experiments showed that the viability of A549 cells decreased with the increase in ZnO-NPs concentration. Meanwhile, it was also found that ZnO-NP treatment induced the production of ROS, the decrease in mitochondrial membrane potential and activation of NLRP3 inflammasome in A549 cells. Furthermore, to explore the underlying molecular mechanisms of ZnO-NP-induced ALI, N-acetyl-L-cysteine (a ROS scavenger), Cyclosporin A (an inhibitor for mitochondrial depolarization) and Glibenclamide (an inhibitor for NLRP3 inflammasome activity) were used to pre-treat A549 cells before ZnO-NPs stimulation in the in vitro experiments, respectively. The results from this study suggested that ZnO-NP-induced ROS production triggered the accumulation of damaged mitochondria and assembly of NLRP3 inflammatory complex, leading to maturation and release of IL-1β. Moreover, ZnO-NP-induced NLRP3 inflammasome activation was partly mediated by mitochondrial damage. Taken together, our study suggested that ZnO-NPs induced ALI through oxidative stress-mediated mitochondrial damage and NLRP3 inflammasome activation and provided insight into the mechanisms of ZnO-NPs-induced ALI.

Antimicrobial activity of in-situ bacterial nanocellulose-zinc oxide composites for food packaging

Active substances such as zinc oxide nanoparticles (ZnO) have been extensively explored due to their antimicrobial properties, low cost and scalability. Yet, their effectiveness is highly dependent on their morphology and specific surface area. Bacterial nanocellulose (BNC) is a suitable carrier due to its ability to transport and deliver active substances. In the case of nanocellulose-ZnO composites, conclusions drawn from antimicrobial studies are often based on only a few representatives of Gram-positive and Gram-negative bacteria. A more comprehensive study using different species and strains, and different methods to assess antimicrobial activity is required. Therefore, in this work, the antimicrobial activity of ZnO suspensions and BNCZnO films was assessed against a wide range of Gram-negative and Gram-positive bacteria using disc diffusion and viable cell count assays. Regarding the results of the disc diffusion assay, the increase of ZnO content (21–27% mZn/mBNCZnO) (in both ZnO suspensions and BNCZnO films), increased antimicrobial activity against all Gram-negative bacteria tested and some Gram-positive bacteria. In the viable cell count assay, BNCZnO films were effective against Escherichia coli (3 log reduction) and Listeria monocytogenes (1–3 log reduction) after 24 h. Low temperatures reduced the antimicrobial activity of BNCZnO.

Suspension of zinc oxide nanoparticles (ZnO-NP) as an intraoperative wound irrigation to prevent infection after fracture fixation

Background: Infection after fracture fixation (IAFF) associated with an implant in orthopaedic surgery is a feared complication, leading to non-union, loss of function, amputation, and even mortality and morbidity to the patient. A biofilm formation on the implant surface increases the difficulty of treatment. Therefore, surgical infection prevention with an effective antiseptic solution is required. This study aims to reveal more about the antibacterial effect of ZnO-NP suspension, particularly Staphylococcus aureus and its biofilm, in preventing surgical infection. Method: An in vitro experimental study with a posttest-only control group design was used to see the antimicrobial activity and inhibitory effect of Staphylococcus aureus biofilm formation between a 20% zinc oxide nanoparticle (ZnO-NP) suspension (20 mg/mL) compared to 0.3% povidone-iodine solution. The statistical result was tested using an independent t-test antibacterial activity. Meanwhile biofilm identification was evaluated using Mann-Whitney & Kruskal Wallis test for each group. Result: 20% ZnO-NP suspension has a minimum inhibitory concentration at 4 μg/mL and a minimum bactericidal concentration at 16 μg/mL, same as 0.3% povidone-iodine administration and its statistically significant (p-value 0.001). Minimum biofilm inhibitory concentration was seen at a concentration of 20% ZnO-NP suspension of 2 μg, while at higher doses, it showed lysis of bacterial cells. Conclusion: 20% ZnO-NP suspension is a promising solution for preventing surgical infection due to its antibacterial and antibiofilm effects.

Suspension of zinc oxide nanoparticles (ZnO-NP) as an intraoperative wound irrigation to prevent infection after fracture fixation

Background: Infection after fracture fixation (IAFF) associated with an implant in orthopaedic surgery is a feared complication, leading to non-union, loss of function, amputation, and even mortality and morbidity to the patient. A biofilm formation on the implant surface increases the difficulty of treatment. Therefore, surgical infection prevention with an effective antiseptic solution is required. This study aims to reveal more about the antibacterial effect of ZnO-NP suspension, particularly Staphylococcus aureus and its biofilm, in preventing surgical infection. Method: An in vitro experimental study with a posttest-only control group design was used to see the antimicrobial activity and inhibitory effect of Staphylococcus aureus biofilm formation between a 20% zinc oxide nanoparticle (ZnO-NP) suspension (20 mg/mL) compared to 0.3% povidone-iodine solution. The statistical result was tested using an independent t-test antibacterial activity. Meanwhile biofilm identification was evaluated using Mann-Whitney & Kruskal Wallis test for each group. Result: 20% ZnO-NP suspension has a minimum inhibitory concentration at 4 g/mL and a minimum bactericidal concentration at 16 g/mL, same as 0.3% povidone-iodine administration and its statistically significant (p-value 0.001). Minimum biofilm inhibitory concentration was seen at a concentration of 20% ZnO-NP suspension of 2 μg, while at higher doses, it showed lysis of bacterial cells. Conclusion: 20% ZnO-NP suspension is a promising solution for preventing surgical infection due to its antibacterial and antibiofilm effects.

Suspension of Zinc Oxide Nanoparticles (ZnO-NP) as an Intraoperative Wound Irrigation to Prevent Infection After Fracture Fixation

Suspension of Zinc Oxide Nanoparticles (ZnO-NP) as an Intraoperative Wound Irrigation to Prevent Infection After Fracture Fixation

Effects of Zinc Oxide Nanoparticles on Neural Tube Development in Early Chicken Embryos.

In recent years, Zinc oxide nanoparticles (ZnO-NPs) have been widely used as a mineral filter in cosmetics. Therefore, the possible exposure of pregnant women to ZnO-NPs is gradually increasing. Thus, we aimed to investigate the effect of ZnO-NPs on neural tube development in early chicken embryos. Fifty pathogen-free fertilized eggs were initially incubated for thirty hours. The eggs were divided into 5 groups. In the control group (C) the egg's apex was opened and closed without any administration. In the distilled water group (DW), 10 microliters of distilled water were injected into the sub-blastodermic area. ZnO-NP suspensions were prepared in distilled water and injected sub-blastodermically into the low, medium and high dose ZnO-NP groups (10 mg/kg, 30 mg/kg, and 50 mg/kg, respectively). Incubation was completed in 72 hours, and embryological and neural tube development was evaluated histologically with a light microscope. Embryos in all groups were evaluated according to the Hamburger-Hamilton (HH) staging. It was observed that the staging progressed by the developmental process between 68-72 hours, which is equivalent to the 19-20th stage of HH. Differentiated otic vesicle, optic cup, lens vesicle, pharynx, and Rathke\'s pouch were all observed in embryo sections. Both forebrain and hindbrain vesicles were easily distinguished in the sections by cranial flexion. Neural tube closure defect was not detected in any of the groups. In our observations, ZnO-NPs did not affect neural tube development at the applied dose ranges. We believe that additional studies with higher doses using a higher number of subjects will help clarify the conflicting data in the literature.

Impact of toxicity effects of zinc oxide nanoparticles in rats within acute and subacute experiments

Introduction. Occupational air is contaminated with zinc oxide nanoparticles in the copper smelting industry, especially in the smelting of brass and copper. A wide range of toxic effects with varied clinical symptomatology is observed in zinc and its compounds. Competitive relations with many other metals, including calcium, copper, and iron, are the foundation of most cases of zinc intoxication. Long-term administration of zinc or its compounds to laboratory rodents affects enzymes, carbohydrates and mineral metabolism. Materials and methods. Subchronic intoxication with repeated intraperitoneal injections and acute low respiratory tract reaction to a single intratracheal injection of zinc nanoparticles were simulated in outbred white rats. Water suspensions of zinc oxide nanoparticles with a 30-80 nm diameter were applied in both experimental models. Upon completion of the exposure, the condition of the rats in all groups was evaluated in many generally accepted criteria for toxicity. The student’s t-test was applied for statistical analysis of the obtained data. Results. Moderate intoxication development in a subchronic experiment is demonstrated. Homogeneous ultrastructural changes in the spleen tissue were revealed. Mitochondrial damage with partial or complete loss of crista is the most common. The fragmentation ratio of DNA was found by a statistically significant increase. A single intratracheal injection of zinc oxide nanoparticles revealed the increase in the attraction of cells capable of their phagocytosis (mainly neutrophils) into the low respiratory tract. This shows their cytotoxicity. Conclusion. Moderate general toxic and cytotoxic effects of zinc oxide nanoparticles on the rat body were identified.

Impact of zinc oxide nanoflowers on growth dynamics and physio-biochemical response of Triticum aestivum

Flower like zinc oxide nanoparticles have been synthesized and the effects of their aqueous suspensions at 200–1000 mg/L on seed germination and seedlings of Triticum aestivum have been investigated. When treated with suspensions of zinc oxide nanoparticles at concentrations of 200–1000 mg/L, germination was reduced to 45% and photosynthetic pigments (chlorophyll a, b, and carotenoids) were also depressed. Enzymatic and non-enzymatic plant defense mechanisms were adversely affected at the maximum concentration. Abnormalities in the concentrations of proline, malondialdehyde, phenols and flavonoids were observed in the roots and shoots of plant due to the zinc oxide nanoparticles at different concentrations.

Preparation, Characterization, and Evaluation of Zinc Oxide Nanoparticles Suspension as an Antimicrobial Media for Daily Use Soft Contact Lenses

ABSTRACT Purpose Infection and inflammation during wearing contact lenses are the problems for the users of daily soft contact lenses. All Gram-positive bacteria, Gram-negative bacteria, and fungi play a role in this problem. In past decades, nanoparticles have largely been studied and shown good antimicrobial activity against various microorganisms. The present study aimed to prepare, characterize, and evaluate zinc oxide nanoparticles (ZNPs) as antimicrobial agents against different microorganisms. Materials and Methods The ZNPs were synthesized in a special structure using the sol-gel process and characterized by XRD, TEM, and EDX. Antimicrobial properties of ZNPs suspension were investigated against different microorganisms (i.e., Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, and Candida albicans) by the Scanning Electron Microscopy of lens surfaces and pour plate method of immersed lens suspension for microbial enumeration. Results The XRD, TEM, and EDX spectrum showed hexagonal structure and no impurity in the nanoparticles with a size of about 20 to 40 nanometers. Sterilized suspension of ZNPs was applied against bacterial species, and the results indicated 4 logarithms (CFU/mL) microbial growth reduction for most Gram-positive and Gram-negative species, except for Pseudomonas aeruginosa that showed 3.5 logarithms (CFU/mL) growth reduction. Furthermore, 1 and 1.7 logarithms (CFU/mL) growth reduction were observed for Candida albicans, applying 250 and 500 ppm ZNPs suspension, respectively, which is an acceptable result for fungal growth inhibition. Findings of this study indicated that the suspensions of ZNPs with 250 and 500 ppm showed acceptable bacteriostatic and bactericidal effects. Conclusions In vitro antimicrobial activity showed that the suspension of ZNPs with 250 ppm concentration could effectively cause a proper reduction and inhibition in the growth of both Gram-positive and Gram-negative microorganisms. Therefore, the results revealed the efficacy of the antibacterial properties of synthesized ZNPs suspension in aqueous media. Abbreviations ZNPs: Zinc oxide nanoparticles; XRD: X-ray diffraction; FWHM: Full width at half maximum; TEM: Transmission electron microscope; SEM: Scanning electron microscope; EDX: Energy-dispersive X-ray spectroscopy; S. aureus: Staphylococcus aureus; S. epidermidis: Staphylococcus epidermidis; L. monocytogenes: Listeria monocytogenes; B. subtilis: Bacillus subtilis; P. aeruginosa: Pseudomonas aeruginosa; S. typhi: Salmonella typhi; E. coli: Escherichia coli; C. albicans: Candida albicans; MK: Microbial keratitis; CLARE: Contact lens-induced acute red eye; CLPU: Contact lens-induced peripheral ulceration; IK: Infiltrative keratitis; AIK: Asymptomatic infiltrative keratitis; MIC: Minimum inhibitory concentration; MBC: Minimum bactericidal concentration; BHI: Brain heart infusion; TSB: Tryptic soy broth; BHIA: Brain heart infusion agar; TSA: Tryptone soya agar.

Gut-brain communication in hyperfunction of 5-hydroxytryptamine induced by oral zinc oxide nanoparticles exposure in young mice

Zinc oxide nanoparticles (ZnONPs) have been widely used in food storage containers and food additives in daily life. However, the impact of oral intake of ZnONPs on nervous system is extremely limited, especially on children and adolescents. In this study, four weeks old mice were treated with either vehicle or ZnONPs suspension solution at 26 mg/kg by intragastric administration for 30 days. Our results demonstrated that oral ZnONPs exposure could induce pathological changes in gut and abnormal excitement of enteric neurons. Interestingly, we found that ZnONPs caused enhancement of 5-hydroxytryptamine (5-HT) in gut by activation of its biosynthesis, transport and receptors, and subsequently resulting in increased level of 5-HT in brain via gut-brain communication by blood. Our data also showed that there were no apparent changes on the expressions of interleukin (Il)-6, Il-1β, C–C motif chemokine ligand 2 (Ccl2), tumor necrosis factor (Tnf) in gut and zinc chelator Mt2 in gut and cortex. Meanwhile, no significant changes were observed on the expressions of tryptophan hydroxylase type 1, 5-HT receptor 3A (Htr3a) and Htr4 in hippocampus and cortex. Our study indicate that oral ZnONPs exposure causes hyperfunction of 5-HT in gut in young mice which may further spread to brain via gut-brain communication.

Plasmonic photodegradation of textile dye Reactive Black 5 under visible light: a vibrational and electronic study

Heterogeneous photocatalysis using semiconductor oxides as a photocatalyst is an intensely employed technique in photodegradation processes under UV irradiation. More recently, plasmonic photocatalysis came in as a technique that promotes intensification of photodegradation processes, in addition to allowing moving the excitation toward the visible range of wavelengths. Such improvements are achieved by hybrid photocatalysts formed between coinage metal nanoparticles, which present the LSPR (Localized Surface Plasmon Resonance) phenomenon, and semiconductor oxides, resulting in plasmonic photocatalysts. In this paper, Ag/ZnO hybrid nanostructured photocatalysts were obtained by associating silver (AgNP) and zinc oxide nanoparticles suspensions (mZnO/mAg ratio of 114.5). The plasmonic photocatalyst Ag∕ZnO was characterized by UV-Vis and powder XRD and used in the degradation of the Reactive Black 5 (RB5) textile dye under visible radiation. The photodegradation process of RB5 was monitored by UV-Vis, resonance Raman (RR), and surface enhanced Raman spectroscopies (SERS) and showed a gain of 54% in the rate constant for the Ag/ZnO plasmonic photocatalyst as compared to the process using only ZnO as the catalyst. Resonance Raman and SERS results provided valuable mechanistic information of degradation pathway under visible light and showed that the initial steps in the mineralization of the dye involve the cleavage of at least one of the azo groups in RB5 and consequent rupture of the chromophoric conjugated π system.

Zinc Oxide Nanoparticles Boosts Phenolic Compounds and Antioxidant Activity of Capsicum annuum L. during Germination

The effects of zinc oxide nanoparticles on seed germination and seedling growth of Capsicum annuum L. were determined in this research. Total phenols content, total flavonoids, and condensed tannins, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant capacity was determined. Results indicated that treatment with zinc oxide nanoparticles (ZnO-NPs) improved seed germination rate during the first seven days. The seed vigor germination increased 123.50%, 129.40% and 94.17% by treatment with ZnO-NPs suspensions at 100, 200 and 500 ppm, respectively. The morphological parameters tested revealed that ZnO-NPs treatments did not significantly affect plumule development, but they had a significant impact (p ≤ 0.01) on radicle length. Suspensions at 100, 200 and 500 ppm of ZnO-NPs inhibited seedling radicle growth and promoted accumulation of phenolic compounds, with a phytotoxic effect in this organ. Results suggested that zinc oxide nanoparticles influence seed vigor and seedling development and promoted the accumulation of desirable phenolic compounds in the radicle.

Effects of zinc oxide nanoparticles on growth and antioxidant enzymes of Capsicum chinense

The effects of suspensions of zinc oxide nanoparticles at concentrations between 100 and 500 mg L−1 on germination of Capsicum chinense seeds and vigor of plants were evaluated using a randomized complete design with four replications, resulting in increased germination and improved development of lengths of plumule and radicle. The activities of peroxidase, catalase and ascorbate peroxidase were determined, showing that at all concentrations the activities of the former two enzymes were increased, whereas the activity of the latter was reduced at 500 mg L−1. Pretreatments of seeds with ZnO nanoparticles can improve germination and development of seedlings and the activities of antioxidant enzymes.

Zinc oxide nanoparticle-induced atherosclerotic alterations in vitro and in vivo.

Engineered zinc oxide nanoparticles (ZnO-NPs) are currently being produced in high tonnage. Exposure to ZnO-NPs presents potential risks to cardiovascular system. Thus far, the toxicological effects of ZnO-NPs on cardiovascular system have not been well characterized. In this study, human coronary artery endothelial cells (HCAECs) were exposed to ZnO-NPs directly or indirectly using a transwell coculture system with human alveolar epithelial cell line A549 to mimic the lung/circulation interaction. It was shown that levels of proinflammatory mediators (interleukin-8 [IL-8] and tumor necrosis factor-α [TNF-α]) and biomarkers of atherosclerogenesis (heme oxygenase-1 [HO-1] and platelet endothelial cell adhesion molecules-1 [PECAM-1]) in the supernatants of culture media were significantly increased. Pretreatment of A549 cells on the apical side of the coculture system with the phagocytosis inhibitor cytochalasin B (CB) blocked ZnO-NP-induced HO-1 and PECAM-1 expression in HCAEC, indicating that endocytosis of ZnO-NPs by alveolar epithelial cells was involved in ZnO-NP-induced HO-1 or PECAM-1 expression in endothelial cells. Moreover, Wistar rats were intratracheally instilled with ZnO-NP suspension and high fat diet (positive control). ZnO-NP treatment induced lung and systemic inflammation, dyslipidemia, increased levels of serum HO-1 and PECAM-1, and aortic pathological damage. Taken together, exposure to ZnO-NPs could induce atherosclerotic alterations, which might involve phagocytosis of nanoparticles and inflammation in the lung.

Role of physical and chemical interactions in the antibacterial behavior of ZnO nanoparticles against E. coli

Zinc oxide (ZnO) nanoparticles (NPs) exhibit antibacterial activity against both Gram-positive and Gram-negative bacteria. However, the antimicrobial mechanism of ZnO NPs remains unclear. In this study, we investigated the interactions among ZnO NPs, released chemicals (Zn2+ and Reactive Oxygen Species, ROS) and Escherichia coli (E. coli) cells. ZnO NPs without contacting with bacterial cells showed strong antibacterial effect. The results of the leakage of intracellular K+ and integrity of carboxyfluoresce in-filled liposomes showed that ZnO NPs have antimicrobial activity against E. coli by non-specifically disrupting E. coli membranes. Traces of zinc ions (1.25mg/L) and hydrogen peroxide (from 1.25 to 4.5μM/L) were detected in ZnO NPs suspensions, but was insufficient to cause the antibacterial effect. However, the addition of radical scavengers suppressed the bactericidal effect of ZnO coated films against E. coli, potentially implicating ROS generation, especially hydroxyl radicals, in the antibacterial ability of ZnO NPs.

Peculiarities of metal oxide nanoparticles obtained in acoustoplasma discharge

Nanoparticles of tungsten, copper, iron, and zinc oxides were synthesized in acoustoplasma discharge. Their size distribution was studied by electron microscopy and laser correlation spectroscopy. Ultrasound was found to narrow significantly the size distribution width of zinc oxide nanoparticles. Water suspensions of zinc oxide nanoparticles showed photoluminescence in red and near infrared spectral ranges, which makes them a promising material for luminescent diagnostics of biological systems.

Targeting Mice Mammary Adenocarcenoma Cells with Zinc Oxide Nanoparticles

The cytotoxic effect of zinc oxide nanoparticles against mice mammary adenocarcenoma cells wascarried out in vitro. The used nanoparticles were synthesized by pulsed laser ablation in liquidmethods; the used liquid was deionized water. Colloidal suspension of zinc oxide nanoparticles wassynthesized by Q-switched Nd: YAG pulse laser device (1064 nm) laser energy was 600 mJ and pulseduration was 10 nanosecond. High purity metallic zinc plate was submerged in 10 ml deionizedwater in 50 ml glass baker and ablated with 1000 pulse at room temperature. The nanospecificitiesof the synthesized nanoparticle colloidal were characterized with UV-Vis scanningspectrophotometer. Atomic force microscope was used to determine the particle size distribution andparticles shape. The ZnO crestless formation was characterized by X-ray diffraction.Mice mammary adenocarcenoma cells was treated with 25, 50, 100 ppm of ZnO nanoparticles.Results indicated a significant toxicity of the ZnO nanoparticles toward cancer cells, this toxicitycorrelated directly with ZnO nanoparticles elevated concentrations. These result need to be furtherinvestigated and the molecular mechanism of ZnO nanoparticles effect should be more clarify.

Particle-specific toxic effects of differently shaped zinc oxide nanoparticles to zebrafish embryos (Danio rerio).

A general approach is proposed that allows for quantifying the relative toxic contribution of ions released from metallic nanoparticles and of the particles themselves, as exemplified for the case of differently shaped zinc oxide (ZnO) nanoparticles (NPs) exposed to zebrafish embryos. First of all, the toxicity of suspensions of ZnO nanoparticles (NP(total))--nanospheres, nanosticks, cuboidal submicron particles (SMPs), and Zn(NO3)2--to the embryos was assessed. The observed toxicity of ZnO NP(total) is assumed to result from the combined effect of the particles present in the suspensions (NP(particle)) and of the dissolved Zn(2+) ions released from the particles (NP(ion)). Different addition models were used to explicitly account for the toxicity of NP(particle). The median lethal concentrations (LC50) of NP(particle) of nanospheres, nanosticks, and SMPs were found to range between 7.1 mg Zn/L and 11.9 mg Zn/L (i.e., to differ by a factor of 1.7). Behavioral performance showed no significant differences among all types of the NP(particle). The median effective concentrations (EC50) of the particles were found to range between 1.0 mg Zn/L and 2.2 mg Zn/L. At the LC50 of each particle suspension, the main contribution to lethality to zebrafish embryos was from the NP(particle) (52%-72%). For hatching inhibition, the NP(particle) was responsible for 38% to 83% of the adverse effects observed. The ZnO nanosticks were more toxic than any of the other NPs with regard to the endpoints mortality and hatching inhibition. The main contribution to toxicity to zebrafish embryos was from the NP(particle) at the LC50 and EC50 of each particle suspension.