Concentrations Of Zinc Oxide Nanoparticles Research Articles

Ecotoxicological Research on the Toxic Impact of Zinc Oxide and Silver Nanoparticles on Oreochromis mossambicus.

Silver nanoparticles (AgNPs) and Zinc oxide nanoparticles (ZnONPs) have been widely used and are eventually been discharged into the natural aquatic ecosystem. The current study examined and correlated the toxicity of AgNPs and ZnONPs on the Mozambique tilapia, Oreochromis mossambicus. Lethal concentration (LC50) was determined with four different concentrations (0.05, 0.10, 0.15, and 0.20 mg/L) of AgNPs and ZnONPs; subsequently, the fishes were exposed to sublethal concentrations for a period of 21 days, and the oxidative stress and antioxidant and nonantioxidant parameters were studied. Results revealed oxidative stress evinced by increased lipid peroxidation (LPO) protein carbonyl activity (PCA), glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) activity, metallothionein (MT) activity, and reduced glutathione in chronic exposure compared with acute exposure. Nonspecific immunological characteristics such as lysozyme (LYZ), myeloperoxidase (MPO), and respiratory burst activity (RBA) were also noticed in the serum. Furthermore, severe histological damages including damages in telangiectasia and epithelial cell hyperplasia were found in the combined treated group with Ag and ZnONPs than in individual treatments. When Ag and ZnONPs were combined, a reduction in the accumulation of Ag was observed in the liver, which increased drastically in individual exposure. The current findings highlight the importance of taking into account the combined exposure and correlation of NPs, their bioavailability, and toxicity in the aquatic ecosystem.

Assessing anticancer, antidiabetic, and antioxidant capacities in green-synthesized zinc oxide nanoparticles and solvent-based plant extracts

Cancer and diabetes represent significant challenges in the field of biomedicine, with major and global impacts on public health. Acacia nilotica, commonly called 'gum arabic tree,' is recognized for its unique biomedical properties. The current study aimed to investigate the pharmacological potential of A. nilotica-based zinc-oxide nanoparticles (ZnO-NPs) in comparison to the ethanol and methanol-based extracts against cancer, diabetes, and oxidative stress. Green synthesis of ZnO-NPs was performed using barks of Acacia nilotica. Different techniques for the characterization of ZnO-NPs, including UV–Visible spectroscopy, Scanning Electron Microscopy, Fourier Transmission Infrared (FT-IR) spectroscopy, and X-ray Diffraction (XRD), were utilized. The morphological analysis of ZnO-NPs revealed that the fine NPs have mean particle sizes of 15 ± 1.5 nm. For the solvent based-extraction, leaves and barks were utilized and dissolved into ethanol and methanol for further processing. The MTT assay revealed that the optimum concentration of ZnO-NPs to inhibit the proliferation of liver cancer cell line HepG2 was 100 μg/mL where 67.0 % inhibition was observed; and both ethanol- and methanol-based extracts showed optimum inhibition at 100 μg/mL. The DPPH assay further demonstrated that 250 μg/mL of ZnO-NPs and 1000 μg/mL of both ethanol- and methanol-based extracts, as the optimum concentration for antioxidant activity (with 73.1 %, 68.9 % and 68.2 % inhibition respectively). The α-Glucosidase inhibition assay revealed that 250 μg/mL of ZnO-NPs and 10 μg/mL of both ethanol- and methanol-based extracts as the optimum concentration for antidiabetic activity (with 95 %, 93.7 % and 93.4 % inhibition respectively). The study provided interesting insights into the efficacy and reliability of ZnO-NPs for potential pharmacological application. Further research should be focused on examining specific pathways and the safety of ZnO-NPs in comparison to solvent-based extracts.

Response of Different Doses of Zinc Oxide Nanoparticles in Early Growth of Mung Bean Seedlings to Seed Priming under Salinity Stress Condition

Background: Salinity impacts physiological processes, including germination, seedling development, ionic balance and water relations, leading to growth inhibition. Mung bean’s early stage is susceptible to salt stress. Our study aimed to mitigate salt stress at early stage using zinc oxide nanoparticles (ZnO-NPs) to enhance mung bean tolerance. Methods: Pot experiment was carried out to incorporate ZnO-NPs into mung bean seedlings. Two Mung bean genotypes, TMB-37 (tolerant) and MH-1314 (sensitive), were chosen. Seeds were primed with ZnO-NPs at various concentrations (0.00 ppm, 50 ppm, 100 ppm, 500 ppm and 1000 ppm) and shown in saline soil. Result: ZnO-NP priming notably increased germination percentage, shoot length and shoot dry weight in both genotypes. In 25-days-old seedlings, ZnO-NPs elevated antioxidant enzyme activity, proline content, especially superoxide dismutase (SOD) and peroxidase (POX) activity, while reducing lipid peroxidation and membrane injury. 1000 ppm ZnO-NPs had the negative impact on the root trait of sensitive genotype. Lower doses of ZnO-NP (50 ppm) concentrations was very effective in mitigating the adverse effect of salinity stress in both the genotypes offering a key approach for Mung bean’s salt stress mitigation.

Formulation of geopolymer coating spray and its antifungal activity

This study aimed to develop an antifungal coating using a geopolymer in combination with zinc oxide nanoparticles (ZnONPs). The coating spray was formulated by adjusting the Si/Al ratio, while maintaining a constant Na/Al ratio. This study assessed the performance of coatings on cement mortar and evaluated their resistance to biodeterioration using Cladosporium under UV and dark conditions. At the optimal Si/Al ratio, an adhesion strength of 0.90 MPa was obtained. However, the adhesion strength abruptly decreased when ZnONPs were introduced to the spray formulation and decreased slightly further with an increase in ZnONP content. Beyond the initial period, mycelial growth on the geopolymer coating without ZnONPs gradually reduced and eventually disappeared after 28 days, which was attributed to the high-pH environment. However, the geopolymer coating incorporating ZnONPs exhibited enhanced antifungal activity compared to that of the ZnONP-free coating. Under UV light, the geopolymer coating with ZnONPs resulted in less mycelial growth than under dark conditions.

A Novel Study on Antioxidant Activity and Catalytic Reduction of Methylene Blue using ZnO Nanoparticles Synthesized via the Middle Part of Walnut Shell (Juglans regia) Extract

Abstract: The synthesized ZnO nanoparticles were characterized using UV-Vis spectroscopy, SEM, XRD, FTIR, and TEM analysis. The catalytic activity of the prepared green catalyst ZnO nanoparticles was also investigated in the dye methylene blue (MB) decomposition. The catalytic decomposition reaction completed within 20 minutes, demonstrating the excellent catalytic properties of ZnO nanoparticles in reducing MB. This research describes the green synthesis of ZnO nanoparticles using an extract of the middle part of a walnut shell (Juglans regia). The antioxidant activities (radical capture capacity) of the synthesized ZnO nanoparticles were evaluated by the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) assay at different ZnO nanoparticle concentrations, and the radical capture activity was achieved at IC50 = 146.32 μg / mL. The radical capture activity was achieved at IC50 = 146.32 μg / mL. The biosynthesis of ZnO nanoparticles was caused by hydroxide precipitation at room temperature after calcination at 450°C.

Amelioration of phytotoxic impact of biosynthesized zinc oxide nanoparticles: Plant growth promoting rhizobacteria facilitates the growth and biochemical responses of Eggplant (Solanum melongena) under nanoparticles stress

The consistently increasing use of zinc oxide nanoparticles (ZnONPs) in crop optimization practices and their persistence in agro-environment necessitate expounding their influence on sustainable agro-environment. Attempts have been made to understand nanoparticle-plant beneficial bacteria (PBB)- plant interactions; the knowledge of toxic impact of nanomaterials on soil-PBB-vegetable systems and alleviating nanotoxicity using PBB is scarce and inconsistent. This study aims at bio-fabrication of ZnONPs from Rosa indica petal extracts and investigates the impact of PBB on growth and biochemical responses of biofertilized eggplants exposed to phyto-synthesized nano-ZnO. Microscopic and spectroscopic techniques revealed nanostructure, triangular shape, size 32.5 nm, and different functional groups of ZnONPs and petal extracts. Inoculation of Pseudomonas fluorescens and Azotobacter chroococcum improved germination efficiency by 22% and 18% and vegetative growth of eggplants by 14% and 15% under NPs stress. Bio-inoculation enhanced total chlorophyll content by 36% and 14 %, increasing further with higher ZnONP concentrations. Superoxide dismutase and catalase activity in nano-ZnO and P. fluorescens inoculated eggplant shoots reduced by 15–23% and 9–11%. Moreover, in situ experiment unveiled distortion and accumulation of NPs in roots revealed by scanning electron microscope and confocal laser microscope. The present study highlights the phytotoxicity of biosynthesized ZnONPs to eggplants and demonstrates that PBB improved agronomic traits of eggplants while declining phytochemicals and antioxidant levels. These findings suggest that P. fluorescens and A. chroococcum, with NPs ameliorative activity, can be cost-effective and environment-friendly strategy for alleviating NPs toxicity and promoting eggplant production under abiotic stress, fulfilling vegetable demands.

Influence of Zinc Oxide Nanoparticles in In Vitro Culture and Bacteria Bacillus thuringiensis in Ex Vitro Conditions on the Growth and Development of Blackberry (Rubus fruticosus L.)

The blackberry, valued for its delicious fruit, has gained attention for its medicinal bioactive compounds. In vitro cultivation methods, including nanoparticle enhancement, are increasingly chosen due to their advantages over traditional propagation techniques. We tested the effect of commercial zinc oxide nanoparticles (ZnONPs) on the growth and development of blackberry (Rubus fruticosus L.) of the Navaho variety in an in vitro culture on MS medium supplemented with 0.6 mg dm−3 BA, 0.1 mg dm−3 IBA, 0.01 mg dm−3 GA3, and various concentrations of zinc oxide nanoparticles: 0 (control), 10, 20, 30, and 40 mg dm−3. The morphological features of the plantlets were assessed two and three months after the start of the culture. Selected biological characteristics of the plantlets were determined. The values of the morphological and biological parameters assessed in the plantlets from in vitro culture depended on the concentration of ZnONPs in the medium. Increasing the concentration of ZnONPs negatively affected the number and length of shoots and roots and the fresh weight of the plantlets. The total phenolic content in the plantlets from the treatments with ZnONPs was lower than in the control plants, but the total antioxidant capacity as measured by the ABTS method was higher. The content of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in the blackberry plantlets decreased at higher concentrations of ZnONPs in the medium. The addition of zinc oxide nanoparticles increased the zinc content and reduced the iron content in the blackberry plantlets. Concentrations of 10–30 mg dm−3 ZnONPs increased the concentrations of potassium, calcium, magnesium, zinc, manganese, and copper, while at the highest concentration of 40 mg dm−3 ZnONPs, the concentrations of these minerals were similar to the control, except for a lower content of calcium and manganese. The plantlets from the in vitro culture growing in the presence of ZnONPs were acclimatized to ex vitro conditions in control soil and soil inoculated with Bacillus thuringiensis. Bacteria added to the ex vitro substrate favourably influenced the growth and development of the shoots and roots of the blackberry plants and their fresh weight.

Green Synthesis, Characterization and Antibacterial Activities of Silk Sericin Capped Zinc Oxide Nanoparticles

In recent years, interest in metal-based antibacterial materials has increased due to microorganisms gaining resistance to antibiotics. Silk sericin obtained from Bombyx mori cocoon has found use in many different areas thanks to its biocompatibility, hydrophilic character and biodegradability. Zinc oxide nanoparticles (ZnONPs) obtained in various zinc salts exhibit broad-spectrum antibacterial properties. In this study, to be produce metal based antibacterial materials, synthesis of silk sericin-coated ZnONPs (SS-ZnONPs) in a green and scalable method was investigated by using silk sericin protein as both reducing and capping agent to obtain ZnONPs. For producing SS-ZnONPs, 2% silk sericin solution was mixed with Zn(NO3)2 solution and the blend solution was heated at 100 °C for a certain period of time. Observing surface plasmon resonance (SPR) peak specific at 380 nm in the UV-vis spectrum of SS-ZnONPs represented the formation of ZnONPs. Then, the chemical, morphological, crystalline, thermal, and antibacterial properties of the synthesized SS-ZnONPs were examined. Characteristic peak of the Zn-O band was found in fourier transform infrared spectroscopy (FTIR) analysis of SS-ZnONPs. According to scanning electron microscopy (SEM) analyses, ZnONPs had morphology similar to cubic/hexagonal shape, showed a uniform structure, and did not represent any agglomerations. In energy dispersive spectroscopy (EDS) analyses of SS-ZnONPs, peaks belonging to carbon, nitrogen, oxygen, sulphur, and zinc elements were observed. The formation of Zn peak indicated that the zinc ions were transformed into ZnONPs. In addition, characteristic peaks of zinc were seen in the X-ray diffractometer (XRD) result of SS-ZnONPs. Thermogravimetric analysis (TGA) showed that the thermal stability and remaining amount of SS-ZnONPs was higher compared to pure silk sericin powder due to the formation of ZnONPs. Lastly, agar well diffusion test was carried out with Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) bacteria and SS-ZnONPs showed antibacterial action against S. aureus. It has been observed that the obtained SS-ZnONPs can be used as antibacterial agents. However, it was also understood that the ZnONPs concentration in this study was low for high antibacterial activity.

Preparation, characterization, and the antimicrobial activity of PVA-PVP/ZnO nanofiber films via indigenous electrospinning setup

The study aimed to produce composite nanofibers (NFs) using the electrospinning method from Polyvinyl alcohol- Polyvinylpyrrolidone/Zinc oxide (PVA-PVP/ZnO) solutions. X-ray diffraction analysis confirmed that in the composite nanofibers, the relative intensity of the dominant crystal plane (101) associated with the wurtzite hexagonal structure of ZnO nanoparticles (NPs) decreased, and its broadness increased in the composite, indicating the presence of an amorphous part in the sample. The existence of functional groups from polymer systems was confirmed by Fourier-transform infrared spectroscopy (FTIR) spectral analysis. Field emission scanning electron microscope (FESEM) images revealed linear and branched uniform nanofiber structures with smooth surfaces of PVA-PVP/ZnO electrospun. The absorbance of PVA-PVP/ZnO NFs increased with the increase in ZnO NPs content, and an absorption band was observed in the ultra violet (UV) region at around 310 nm. The calculation of the optical energy gap using the absorption spectra fitting (ASF) approach roughly aligned with Tauc's model, ranging from 3.47 to 3.24 eV. The highest inhibition zone (14 and 15 mm) was observed at the ratios of 4 and 6 wt.% of ZnO NPs against gram-negative bacteria (Escherichia coli).

Impact of ZnO nanopriming on physiological and biochemical traits of wheat (Triticum aestivum L.) seedling

To ascertain the ideal dosage of ZnO NPs (Zinc Oxide Nanoparticles), we conducted an investigation on the priming effects of varying concentrations of ZnO NPs on germination and physio-biochemical parameters of wheat. In this study, ZnO NPs were synthesized and characterized for their physico-chemical properties followed by confirmation of the formation of ZnO NPs. Throughout this study, wheat seeds were subjected to ZnO NPs at various concentrations of 5, 50, 100, 250, and 500 ppm for a period of 4 h via continuous aeration. The primed seeds were sowed in plastic bags, allowed to grow for 21 days, following which comprehensive evaluations of physio-biochemical attributes were conducted. At 250 ppm, an impressive 100% of seeds successfully germinated compared to the control group. The examined physiological factors such as shoot length, root length, and fresh as well as dry weights of leaf and root tissues all exhibited notable increases with the ascending concentrations of ZnO NP up to 250 ppm. However, beyond this threshold, at 500 ppm, these parameters experienced a decline. Inductively coupled plasma atomic absorption spectrophotometer (ICP-AAS) measurements validated the progressive increase in Zinc content in the nanoprimed seedlings, further affirming the dose-dependent trend. Zinc oxide nanoparticles notably improved key biochemical features, including elevated levels of total chlorophyll, malondialdehyde (MDA), total protein, and the accumulation of osmolytes such as proline and glycine-betaine. Additionally, the presence of ZnO NPs led to increased activity of antioxidant enzymes like superoxide dismutase (SOD) and catalase in a dose-dependent mananer. Collectively, the amassed data underscores the efficacy of the 250 ppm ZnO NPs treatment, which emerged as superior in comparison to both the control group and other administered treatments. These findings underscore the potential of ZnO NPs at a concentration of 250 ppm as a valuable seed nanopriming agent, effectively enhanced germination and robust early-stage growth in young plants.

تأثير دقائق اوكسيد الزنك النانوية المصنعة بايولوجيًا على النمط الظاهري والجيني للغشاء الحيوي لبكتريا Proteus mirabilis

تصنف بكتريا Proteus mirabilis كثالث مسبب لالتهاب المجاري البولية المصاحب لتركيب أنابيب القسطرة البولية. تعد الاغشية الحيوية من عوامل الضراوة اللتي تستعملها البكتريا لمقاومة المضادات الحيوية وفي ضل تطور مقاومة البكتريا للمضادات الحيوية, صار لزامًا على العلماء والباحيثن في مجال الاحياء المجهرية أيجاد بدائل ذات كفائة عالية قادرة على اختراق جدار الخلية البكتيرية وبالتالي قتلها.في السنوات الاخيرة, اكتسبت دقائق النانو المصنعة بايولوجيا والصديقة للبيئة أهتمامًا كبيرًا من قبل الباحثين لأمتلاكها خصائص مميزة كصغر حجمها المتناهي واشكالها المختلفة يمَكنهم من استعمالها كمواد مضادة للبكتيريا في مختلف المجلات الطبية والصحية. تهدف هذه الدراسة الى التحري عن قدرة دقائق اوكسيد النحاس النانوية المصنعة بايولوجيا على تثبيط تكوين الغشاء الحيوي المنتج من قبل بكتيريا Proteus mirabilis. أنتجت هذه الدقائق بأستعمال راشح بكتيري يحتوي على الانزيمات المختزلة لملح النحاس واستخدمت عدة تقنيات لتحديد الصفات الفيزيائية المظهرية لدقائق النانو المنتجة حيث استخدمت تقنية XRD لتأكيد التركيب خماسي الشكل لهذه الدقائق , بينما استعملت تقنية TEM لتحديد قطر الجزيئات المنتجة بمعدل 84.45 نانومتر. اما FESEM فقد تم استخدامه لتحديد الصفات الخارجية لسطح جزيئات النانو المنتجة , تم تأكيد النتائج بأستخدام تقنية AFM للكشف عن توزيع و وعورة جزيئات النانو.اما UV فقد سجلت ااقصى امتصاصية على الطول الموجي nm287 .تم التحري في هذه الدراسة عن فعالية دقائق اوكسيد النحاس النانوية في منع تكون الغشاء الحيوي حيث أستعمل مستحلب دقائق اوكسيد النحاس النانوي بالتركيز تحت القاتل 32 μg/ml . سجلت نتائج هذه الدراسة انخفاضا ملحوضَا في انتاج الغشاء الحيوي للبكتريا المنتجه له حيث سجلت العزلات ذات الانتاجية العالية للغشاء الحيوي ضعفأ في الانتاج بعد معاملتها بالتركيز المستعمل من دقائق اوكسيد النحاس النانوية. جاء تأثير هذه الدقائق على كل من النمط الظاهري والتعبير الجيني لجين LuxS المسؤول عن تكوين الغشاء الحيوي بأستخدام تقنية rtPCRحيث سجلت الدراسة انخفاضا في التعبير الجيني لهذا الجين بعد معاملة سلالات البكتريا قيد الدراسة بدقائق اوكسيد النحاس النانوية مقارنتاً بالعزلات غير المعاملة. من خلال نتائج هذه التجربة يمكن التوصل الى امكانية اعتماد دقائق اوكسيد الزنك النانوية كعامل مضاد للبكتيريا عن استخدامه بالتركيز المناسب.

Response and Resilience of Scenedesmus rubescens Microalgae to ZnO Nanoparticles

Microalgae are microorganisms of great importance for aquatic ecosystems. The investigation of their interaction with potential environmental stressors like nanoparticles (NPs) is essential in order to assess their behavior and fate in aquatic ecosystems. The scope of this work is to investigate the response and potential toxic effects of the short-term exposure of Scenedesmus rubescens microalga to zinc oxide (ZnO) NPs with various initial nitrate concentrations in the culture medium. Scenedesmus rubescens was cultivated in four different compositions of modified BG-11 with a nitrate content varying from 0 to 300 mg/L, and it was exposed to four concentrations of ZnO NPs, ranging from 0.081 to 81 mg/L. S. rubescens was found to be resilient towards ZnO NP toxicity. The results also highlight the fact that the toxic effects of ZnO NPs on microalgae are highly dependent on the species tested. The nitrate content of the medium did not affect the toxicity of ZnO NPs but had a significant impact on cell concentration, as it was observed at an initial nitrate concentration of 300 mg/L. Further investigation should focus on studying the morphological and metabolic characteristics and mechanisms contributing to this species’ resilience.

Synthesis of green zinc-oxide nanoparticles and its dose-dependent beneficial effect on spermatozoa during preservation: sperm functional integrity, fertility and antimicrobial activity.

Introduction: The development of an effective extender is important for semen preservation and the artificial insemination (AI) industry. This study demonstrates the beneficial effect of zinc oxide nanoparticles (ZnO-NPs) as an additive to semen extenders to improve semen quality, fertility, and antibacterial activity during liquid preservation in a boar model. Methods: Initially, to find out the safe concentration of ZnO-NPs in sperm cells, a wide range of ZnO-NP concentrations (0, 5, 10, 50, 100, 500, and 1,000μM) were co-incubated with sperm at 37°C for a cytotoxic study. These NP concentrations were compared to their salt control zinc acetate (ZA) at the same concentrations and to a control group. The effect of the different concentrations of ZnO-NPs on sperm motility, membrane integrity, mitochondrial membrane potential (MMP), and apoptosis was assessed. Accordingly, the non-toxic dose was selected and supplemented in MODENA extender to determine its beneficial effect on the boar semen parameters mentioned and the lipid peroxidation (LPO) levels during liquid preservation at 16°C for 6days. The non-cytotoxic dosage was subsequently chosen for AI, fertility investigations, and the evaluation of the antibacterial efficacy of ZnO-NPs during preservation hours. An antibacterial study of ZnO-NPs and its salt control at doses of 10μM and 50μM was carried out by the colony forming unit (CFU) method. Results and discussion: The cytotoxic study revealed that 5, 10, and 50μM of ZnO-NPs are safe. Consequently, semen preserved in the MODENA extender, incorporating the non-toxic dose, exhibited 10 and 50μM ZnO-NPs as the optimal concentrations for beneficial outcomes during liquid preservation at 16°C. ZnO-NPs of 10μM concentration resulted in a significantly (p < 0.05) improved conception rate of 86.95% compared to the control of 73.13%. ZnO-NPs of 10 and 50μM concentrations exhibit potent antimicrobial action by reducing the number of colonies formed with days of preservation in comparison to the negative control. The investigation concluded that the incorporation of 10μM ZnO-NPs led to enhancements in sperm motility, membrane integrity, and MMP, attributed to a reduction in the malondialdehyde (MDA) levels. This improvement was accompanied by a concurrent increase in fertility rates, including farrowing rate and litter size, during the liquid preservation process. Furthermore, ZnO-NPs exhibited an antimicrobial effect, resulting in decreased bacterial growth while preserving boar semen at 16°C for 6days. These findings suggest that ZnO-NPs could serve as a viable alternative to antibiotics, potentially mitigating antibiotic resistance concerns within the food chain.

Enhancement of Visible Light Antibacterial Activities of Cellulose Fibers from Lotus Petiole Decorated ZnO Nanoparticles.

Cellulose/ZnO (CZ) nanocomposites are promising antimicrobial materials known for their antibiotic-free nature, biocompatibility, and environmental friendliness. In this study, cellulose fibers extracted from lotus petioles were utilized as a substrate and decorated with various shapes of ZnO nanoparticles (NPs), including small bean, hexagonal ingot-like, long cylindrical, and hexagonal cylinder-shaped NPs. Increasing zinc salt molar concentration resulted in highly crystalline ZnO NPs forming and enhanced interactions between ZnO NPs and -OH groups of cellulose. The thermal stability and UV-visible absorption properties of the CZ samples were influenced by ZnO concentration. Notably, at a ZnO molar ratio of 0.1, the CZ 0.1 sample demonstrated the lowest weight loss, while the optical band gap gradually decreased from 3.0 to 2.45eV from the CZ 0.01 to CZ 1.0 samples. The CZ nanocomposites exhibited remarkable antibacterial activity against both Staphylococcus aureus (S. aureus, Gram-positive) and Escherichia coli (E. coli, Gram-negative) bacteria under visible light conditions, with a minimum inhibitory concentration (MIC) of 0.005mg/mL for both bacterial strains. The bactericidal effects increased with higher concentrations of ZnO NPs, even achieving 100% inhibition. Incorporating ZnO NPs onto cellulose fibers derived from lotus plants presents a promising avenue for developing environmentally friendly materials with broad applications in antibacterial and environmental fields.

Exposure to zinc oxide nanoparticles induced reproductive toxicities in male Sprague Dawley rats

BackgroundThis research delves into the reproductive toxicology of zinc oxide nanoparticles (ZnO-NPs) in male Sprague Dawley rats. It specifically examines the repercussions of Zn accumulation in the testes, alterations in testosterone levels, and histopathological changes in the gonadal tissues. AimsThe primary objective of this study is to elucidate the extent of reproductive toxicity induced by ZnO-NPs in male Sprague Dawley rats. The investigation aims to contribute to a deeper understanding of the potential endocrine and reproductive disruptions caused by ZnO-NPs exposure. MethodsCharacterization techniques including SEM-EDX and XRD affirmed the characteristic nature of ZnO-NPs. Twenty-five healthy post weaning rats (200–250 g) were intraperitoneally exposed to different concentrations of ZnO-NPs @ 10 or 20 or 30 mg/kg BW for 28 days on alternate days. ResultsResults showed significant dose dependent decline in the body weight and testicular somatic index of rats. It also showed significant dose dependent accumulation of Zn in testis with increasing dose of ZnO-NPs. Conversely, serum testosterone level and sperm count were reduced with increasing dose of ZnO-NPs. Histological results showed dose dependent abnormalities i.e., vacuolization, edema, hemorrhage, destruction of seminiferous tubules, loss of germ cells and necrosis in rat testis. ConclusionThe findings of this study clearly indicate that high doses of zinc oxide nanoparticles (ZnO-NPs) can adversely affect the structural integrity and functional efficacy of the male reproductive system. Given these results, it becomes crucial to implement stringent precautionary measures in the utilization of ZnO-NPs, particularly in cosmetics and other relevant sectors. Such measures are imperative to mitigate the toxicological impact of ZnO-NPs on the male reproductive system and potentially on other related physiological functions. This study underscores the need for regulatory vigilance and safety assessments in the application of nanotechnology to safeguard human health.

Doping zinc oxide and titanium dioxide nanoparticles with gold induces additional oxidative stress, membrane damage, and neurotoxicity in Mytilus galloprovincialis: Results from a laboratory bioassay

BackgroundWhile previous studies have provided insights into the effects of zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles (NPs) on aquatic organisms, there is still a substantial amount of information lacking about the possible effects of their doped counterparts. The goal of the current work was to address this gap by examining Mytilus galloprovincialis reaction to exposure to doped and undoped nanoparticles. MethodsTwo concentrations (50 or 100 µg/L) of undoped ZnO and TiO2 NPs, as well as their gold (Au) doped counterparts, were applied on mussels for 14 days, and the effects on biomarkers activities in digestive glands and gills were assessed by spectrophotometry. ResultsThe NPs were quasi-spherical in shape (below 100 nm), stable in seawater, and with no aggregation for both doped and undoped forms. Analytical results using inductively coupled plasma atomic emission spectroscopy indicated the uptake of NPs in mussels. Furthermore, it was found that biometal dyshomeostasis could occur following NP treatment and that doping the NPs aggravated this response. At the biochemical level, exposure to undoped NPs caused membrane damage, neurotoxic effect, and changes in the activities in the gills and digestive glands of superoxide dismutase, catalase, and glutathione-S-transferase, in a concentration and organ-dependent manner. ConclusionDoping ZnO NPs and TiO2NPs with Au induced additional oxidative stress, membrane damage, and neurotoxicity in mussels.

Zea mays-mediated fabrication and characterization of zinc oxide nanoparticles with enhanced antibacterial and antioxidant properties

This study presents the synthesis of zinc oxide nanoparticles (ZnO-NPs) using Zea mays leaf extract as a natural reducing and stabilizing agent. The synthesized ZnO-NPs were comprehensively characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FTIR). XRD analysis confirmed the crystalline nature of the NPs, while SEM revealed their morphology and size distribution. EDX confirmed the elemental composition of the synthesized ZnO-NPs, and FTIR provided insights into the functional groups involved in NPs formation. The antibacterial activity of ZnO-NPs was evaluated against a selected bacterial strain using the agar well diffusion method. The results demonstrated a zone of inhibition around the wells containing ZnO-NPs, indicating their potential antibacterial efficacy. The antioxidant activity of ZnO-NPs was assessed by their ability to scavenge ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) free radicals. It was found that the scavenging activity got increased with the concentration of ZnO-NPs, indicating their potential as antioxidants.

Activity of coatings based on chitosan, chitosan and ZnO nanoparticles against fungi isolated and molecularly identified from fruits with export potential in the northern area of Peru

Post-harvest losses of export fruits cause considerable economic reductions, being fungal action one of the main causes. To control these, fungicides are used, many of which have high toxicity and residual power. The search for alternatives to their use becomes an important research topic. The objective of this research was to evaluate coatings based on chitosan, chitosan and ZnO nanoparticles (NPs) to inhibit fungi isolated from fruits with export potential in northern Peru. Firstly, fungi were isolated and identified, molecularly based on the internal transcribed spacer (ITS) gene. From blueberry, lemon, grape and golden berry. Chitosan coatings were prepared, with different concentrations of chitosan and ZnO nanoparticles. These coatings were evaluated in vitro on some of the isolated fungi using the inhibition zone technique. The prepared coatings showed antifungal effect against Alternaria Alternata (blueberry), Aspergillus tubingensis (lemon), Aspergillus niger (lemon), Thielaviopsis ethacetica (lemon) and Aspergillus niger (golden berry). It was determined that the concentration of chitosan NPs had no effect on the antifungal capacity of the coatings, while the ZnO NPs did have a directly proportional effect. Coatings based on chitosan and chitosan and ZnO NPs have potential for use as antifungal agents in fruits for exportation.

Subacute toxicity and endocrine-disrupting effects of Fe2O3, ZnO, and CeO2 nanoparticles on amphibian metamorphosis.

This study evaluated the potential toxic and endocrine-disrupting effects of sublethal concentrations of Fe2O3, CeO2 and ZnO nanoparticles (NPs) on amphibian metamorphosis. Tadpoles were exposed to several NPs concentrations, reaching a maximum of 1000µg/L, for up to 21days according to the amphibian metamorphosis assay (AMA). Some standard morphological parameters, such as developmental stage (DS), hind limb length (HLL), snout-to-vent length (SVL), wet body weight (WBW), and as well as post-exposure lethality were recorded in exposed organisms on days 7 and 21 of the bioassay. Furthermore, triiodothyronine (T3), thyroxine (T4) and malondialdehyde (MDA) levels and the activities of glutathione S-transferases (GST), glutathione reductase (GR), catalase (CAT), carboxylesterase (CaE), and acetylcholinesterase (AChE) were determined in exposed tadpoles as biomarkers. The results indicate that short-term exposure to Fe2O3 NPs leads to toxic effects, both exposure periods cause toxic effects and growth inhibition for ZnO NPs, while short-term exposure to CeO2 NPs results in toxic effects and long-term exposure causes endocrine-disrupting effects. The responses observed after exposure to the tested NPs during amphibian metamorphosis suggest that they may have ecotoxicological effects and their effects should be monitored through field studies.

Evaluation of antimicrobial and antioxidant activity of zinc oxide nanoparticles biosynthesized with Ziziphus spina-christi leaf extracts

Background: Due to their simplicity, eco-friendliness, availability and non-toxicity, the greener fabrication of metal and metal oxide nanoparticles has been a highly attractive research area over the last decade. Aim: This study aimed to assess the antioxidant and antimicrobial activities of the green synthesized zinc oxide nanoparticles (ZnO-NPs) using an aqueous leaf extract of Ziziphus spina-christi. Method: The antioxidant property of ZnO-NPs was analyzed by the α, α-diphenyl-β-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2). Additionally, the diffusion agar method assessed the antimicrobial activities against bacteria and fungi. Results: ZnO-NPs synthesized by Z. spina-christi had shown promising H2O2 and DPPH free radical scavenging actions compared to vitamin C. The ZnO-NPs exhibited significant antibacterial activity against the tested bacteria with various susceptibility as a concentration-dependent effect. The largest zone of inhibition for Staphylococcus aureus (S. aureus) was observed (36 ± 2 mm) compared to Escherichia coli (E. coli) (15 ± 2 mm) by the same concentration of ZnO-NPs. The ZnO-NPs showed remarkable antifungal activity against Aspergillus niger. Conclusion: It can be concluded that, ZnO-NP have been imposed as suitable antimicrobial agent being able to combat both S. aureus and E. coli in vitro.