Concentrations Of ZnO NPs Research Articles

Neurotoxicity and Cardiovascular Toxicity of Zinc Oxide Nanoparticles to Oryzias melastigma.

Zinc oxide nanoparticles (ZnO NPs) are widely used in manufacturing cosmetic and pharmaceutical products. Although previous studies have reported their toxic effects on fish, the underlying mechanisms behind their toxic effects are yet to be identified. This study evaluated the impact of ZnO NPs on marine medaka's survival, heart rates (Oryzias melastigma), and the expression of genes linked to neurotoxicity and cardiovascular toxicity. Marine medaka samples were exposed to ZnO NPs at varying concentrations: 0.01, 0.1, 1, and 10 mg/L. Survival rates and heart rates were monitored on the 12th day postfertilization. Gene expression related to neurotoxicity (α-tubulin, elavl3, gap43, gfap) and cardiovascular toxicity (cdh2, atp2a1, cacna1da, crhr1, ahrra, arnt2) was assessed by performing real-time polymerase chain reaction. The survival rate of marine medaka samples was not significantly impacted by exposure to up to 1 mg/L of ZnO NPs; however, exposure to 10 mg/L of ZnO NPs resulted in a 60% reduction in survival rate. The heart rate of the samples did not significantly change across all concentrations. High ZnO NP concentrations (10 mg/L) significantly suppressed the expression of neurotoxic and cardiotoxic genes, including elavl3 and gfap. ZnO NPs exhibited dose-dependent toxic effects on the marine medaka samples by affecting the expression of genes related to neurological and cardiovascular functions. These findings underscore the potential risks of ZnO NPs to aquatic organisms. The distinct toxic actions of ZnO NPs and dissolved ions complicate the interpretation of results, as this study did not measure ion release, a critical factor in understanding NP toxicity. Moreover, ZnO NPs may cause oxidative stress and disrupt cellular pathways. Furthermore, without distinguishing between NP and ion effects, it is challenging to determine the exact cause of toxicity. These findings highlight the need for future studies to measure dissolved ions and particles separately to clarify their contributions to toxicity, where the mechanisms of action are still debated.

Zinc Oxide Nanoparticles Treatment Maintains the Postharvest Quality of Litchi Fruit by Inducing Antioxidant Capacity

Pericarp browning and fruit decay severely reduce the postharvest quality of litchi. Improving the antioxidant capacity of the fruit is an effective way to solve these problems. In our study, the appropriate zinc oxide nanoparticles (ZnO NPs) treatment and its mechanism of action on the storability of litchi was investigated. Litchi fruit was soaked in a 100 mg·L−1 ZnO NPs suspension, water, and 500 mg·L−1 prochloraz for 2 min, respectively. The results showed that the ZnO NPs treatment delayed pericarp browning and decay in litchi fruit and was more effective than prochloraz treatment. The ZnO NPs-treated fruit showed significantly increased contents of total anthocyanin, total phenols, and activities of DPPH scavenging, superoxide dismutase, and glutathione peroxidase, as well as the lowest activities of polyphenol oxidase and laccase. ZnO NPs generated hydrogen peroxide and superoxide anion radicals, which were beneficial in slowing down the decay and inducing antioxidant capacity. However, these reactive oxygen species also consumed catalase, peroxidase, glutathione, and glutathione peroxidase. This means that litchi should be treated with an appropriate concentration of ZnO NPs. We concluded that treatment with a 100 mg·L−1 ZnO NPs suspension could induce antioxidant capacity, which is a promising and effective method to maintain the postharvest quality of litchi.

Zinc oxide nanoparticle biofortification of lentil seedlings enhances plant growth and zinc bioavailability in rats

This study aimed to evaluate the potential of zinc oxide nanoparticles (ZnO NPs) in the biofortification of lentil seedlings and subsequently improve the Zn status in rats. In the first phase of the study, the effects of various ZnO NPs concentrations (0, 10, 20, 40, 80, and 160 ppm) on the lentil growth, Zn accumulation, and other physiological parameters were investigated. Subsequently, the rats were fed ZnO NP-biofortified lentil seedlings (20 and 160 ppm) to assess their impact on animal health and Zn status. The results highlighted a concentration-dependent response of lentil seedlings to ZnO NPs, with optimal growth observed at 20 ppm, whereas higher concentrations inhibited lentil growth. Pigment and biochemical analyses revealed a complex interplay between chlorophyll, carotenoids, soluble sugars, and proteins with distinct responses to nanoparticle concentrations. Elevated levels of hydrogen peroxide and malondialdehyde of lentil seedlings at high concentrations of ZnO NPs suggest oxidative stress, countered by the upregulation of antioxidant enzymes and increased phenolic compounds. On the other hand. animal studies have showed that ZnO NP-biofortified lentil seedlings enhance serum zinc and magnesium levels in rats without affecting body weight. While serum triglyceride levels of rats decreased in both treatment groups, an elevation in creatinine and a marked increase in aspartate aminotransferase (AST) levels were observed at a higher ZnO NP concentration (160 ppm), indicative of potential kidney and liver stress. Paradoxically, serum iron levels were lower in all groups consuming lentil seedlings than in the control group, suggesting a potential interaction between lentil components and iron metabolism. These findings suggest that ZnO NP-biofortified lentils may be a promising approach to enhance Zn nutrition; however, further investigation is needed to optimize ZnO NPs concentration and assess long-term safety.

UNMASKING THE POWER OF METAL OXIDE NANOPARTICLES FOR SELF-CLEANING HEAVY DENIM: INVESTIGATING AND OPTIMIZING PROCESS PARAMETERS

The textile industry is consistently integrating cutting-edge technologies, introducing materials with multifaceted features, such as odour resistance, hydrophobicity, durability, and self-cleaning capabilities. This transformation is facilitated by the application of nanotechnology. The focal point of this experimental endeavour lies in closing the gap in employing ZnO nanoparticles on high GSM denim fabric, enhancing self-cleaning, UV protection, and antimicrobial capabilities. Initially, a solution containing nanoparticles, binder, softener, ethanol, and their auxiliaries was formulated. Zinc oxide nanoparticles, along with their auxiliaries, were applied to the denim using the pad-dry-cure and pad-dry-steam methods. Various trials were conducted to optimize the concentration of ZnO NPs, with the formulation containing 5% ZnO NPs, 5% binder, and 25% ethanol. Experimentation ensued to establish optimal time–temperature profiles for drying, curing, and steaming. Comprehensive evaluations, including drop tests, stain tests, colour strength assessments, crocking tests, SEM analysis, antimicrobial testing and UV protection factor determination were conducted on the samples. The study revealed that fixation of the self-cleaning finish by curing gives better results than by steaming. SEM examination highlighted the distribution of ZnO nanoparticles on the denim fabric. Lastly, antimicrobial properties were assessed, concluding that treated fabrics exhibited antibacterial activity compared to untreated fabrics.

Effects of Zinc Oxide Nanoparticles (ZnO NPs) on Growth, Immune Responses and Histopathological Alterations in Asian Seabass (Lates calcarifer, Bloch 1790) under Low-Salinity Conditions.

In the present study, Asian seabass (Lates calcarifer, Bloch) fingerings were used as an animal model to investigate the toxicological effects of zinc oxide nanoparticles (ZnO NPs) under 5 ppt estuarine conditions. The fish were exposed to 0, 1, 5 or 50 ppm ZnO NPs for 8 weeks. It was found that ZnO NP concentrations of 5-50 ppm negatively affected several growth rate parameters, such as the weight and total length of the fish. Additionally, 5 and 50 ppm ZnO NPs led to 32.55% and 100% mortality, respectively, after 8 weeks after exposure (WAE). Furthermore, compared with the control, exposure to 1-50 ppm ZnO NPs strongly affected hematological indices, such as total blood cells, red blood cells, leukocytes and hematocrit, and suppressed lysozyme activity, superoxide anion production and bactericidal activity. High Zn concentrations accumulated in the head kidney, gills and liver, whereas low levels were detected in the gut, skin and muscle. Expression analysis of immune-related genes via quantitative real-time RT-PCR revealed that 5 and 50 ppm ZnO NPs significantly upregulated the cc and cd4 genes at 1 WAE. In contrast, 50 ppm ZnNPs downregulated the expression levels of the cd8, cc, hsp70, hsp90, tcrα, lyz and igmh genes at 1 WAE (p < 0.05). Finally, at 8 WAE, histopathological analysis revealed that 5 and 50 ppm ZnO NPs severely induced alterations in the head kidney, gills and liver.

Characterization and toxicity evaluation of chitosan/ZnO nanocompoite as promising nano-biopolymer for treatment of synthetic wastewater

Nanotechnology advances wastewater treatment through the application of Nano entities that optimize contaminant removal and enhance water purification efficacy. In this study, ZnO nanoparticles (ZnO NPs) were synthesized using Klebsiella pneumoniae, subsequently, a chitosan/ZnO nanocomposite (CS/ZnO NC) was prepared for removing reactive black 5 (RB-5) dye from synthetic wastewater. The biosynthesized nanomaterials were characterized using UV–VIS, FTIR, XRD, SEM and TEM techniques. The UV–Vis absorbance peaks at 370 nm and 350 nm corresponded to the characteristic surface plasmon resonance of ZnO NPs and the CS/ZnO NC, respectively. Additionally, FTIR analysis identified the various functional groups associated with ZnO NPs and the CS/ZnO NC. XRD analysis revealed their crystallinity to be approximately 22.44 and 25.76, respectively. The SEM images of ZnO NPs and the CS/ZnO NC show hexagonal plate-like particles with sizes of 33.66 nm and 38.64 nm, respectively. Four concentrations of ZnO NPs and CS/ZnO NC (0.25, 0.5, 1, and 2 mg/mL) were evaluated for RB-5 degradation at three different levels (25, 50, and 100 mg/L). Statistical analysis showed that chitosan/ZnO NC achieved 95 % dye degradation, compared to 81 % degradation with the same amount of ZnO nanoparticles. Furthermore, a pot experiment was carried out to evaluate the phytotoxicity effects of treated wastewater on wheat (Triticum aestivum L.). Both ZnO NPs and CS/ZnO NC did not significantly affect the viability of epithelial retinal cell lines at concentrations up to 100 µg/mL, suggesting a safe cytotoxic profile within this dosage range. Overall, CS/ZnO NC proved effective for treating industrial wastewater, making it suitable for recycling in agricultural applications

Photoperiod-dependent effects of zinc oxide nanoparticles on the growth and reproduction of Daphnia pulex

The discharge of metal nanoparticles into the water inevitably poses a threat to aquatic organisms and the balance of the aquatic ecosystem. Photoperiod is one of the most important ecological factors for the development of cladocerans. In addition, different light conditions can also affect the toxicity of metal nanoparticles. In this study, we studied the effects of four photoperiods (8L/16D, 10L/14D, 14L/10D, and 16L/8D) combined with three concentrations of ZnO NPs (0 mg L−1, 0.05 mg L−1, and 0.10 mg L−1) on the growth and reproduction of Daphnia pulex. With the increase of photoperiod, the maternal body size and growth rate increased first and then decreased; the first time to reproduction was advanced, and broods and the total offspring also increased. Under the influence of ZnO NPs, growth rate and reproductive capacity were inhibited. The photoperiod 8L/16D and 16L/8D interacted with ZnO NPs on the growth of D. pulex, which significantly decreased the growth rate. Besides, the interaction between photoperiod 8L/16D and ZnO NPs decreased the reproduction ability of D. pulex. These results suggest that the effects of zinc oxide nanoparticles on the growth and reproduction of D. pulex is photoperiod dependent, which is useful for assessing the risk of pollutants to cladoceras under different light conditions.

Biogenic zinc oxide nanoregulator determines the quantitative analysis of morpho-anatomical and antioxidant capacity in Lactuca sativa L.

Zinc oxide nanoparticles (ZnO NPs) can possibly serve as a pervasive source of essential nutrient zinc in agricultural crops in the future. The major environmental concerns with ZnO NPs might be their toxicity and incorrect dosage, which might lead to crop damage and environmental pollution. Interplay between ZnO NPs and Lactuca sativa (L. sativa) will be of interest, yet little is known about apropos interaction of these two, which will assist in optimizing the dose of ZnO NPs for their commercial use in agriculture. The current study aimed to investigate the growth, anatomical, and antioxidative responses of L. sativa against ZnO NPs and zinc acetate. ZnO NPs were foliar sprayed with concentrations of 0, 25, 50, and 100 ppm. ZnO NPs remarkably promoted L. sativa growth, leaf water content, and biomass accumulation; however, they declined root growth. The foliar spray of ZnO NPs improved the thickness of the stem hypodermis, cortex, pericycle, and phloem, while decreasing the stem diameter, thickness of the epidermis, and number of vascular bundles. ZnO NPs rigorously declined the cell area of xylem but slightly improved it in phloem. Unlike stem cells' anatomical responses to ZnO NPs, the root cells behaved otherwise. Overall, the antioxidative activity of L. sativa considerably improved at 25 ppm concentration and decreased at 100 ppm. Generally, low and medium concentrations of ZnO NPs promoted plant morphological, anatomical, and antioxidant traits, while higher doses inhibited the same traits. Contrary to this, Zn acetate displayed severe toxic effects on almost all studied anatomical traits.

Low-dose zinc oxide nanoparticles trigger the growth and biofilm formation of Pseudomonas aeruginosa: a hormetic response

IntroductionHormesis describes an inverse dose-response relationship, whereby a high dose of a toxic compound is inhibitory, and a low dose is stimulatory. This study explores the hormetic response of low concentrations of zinc oxide nanoparticles (ZnO NPs) toward Pseudomonas aeruginosa.MethodSamples of P. aeruginosa, i.e. the reference strain, ATCC 27,853, together with six strains recovered from patients with cystic fibrosis, were exposed to ten decreasing ZnO NPs doses (0.78–400 µg/mL). The ZnO NPs were manufactured from Peganum harmala using a chemical green synthesis approach, and their properties were verified utilizing X-ray diffraction and scanning electron microscopy. A microtiter plate technique was employed to investigate the impact of ZnO NPs on the growth, biofilm formation and metabolic activity of P. aeruginosa. Real-time polymerase chain reactions were performed to determine the effect of ZnO NPs on the expression of seven biofilm-encoding genes.ResultThe ZnO NPs demonstrated concentration-dependent bactericidal and antibiofilm efficiency at concentrations of 100–400 µg/mL. However, growth was significantly stimulated at ZnO NPs concentration of 25 µg/mL (ATCC 27853, Pa 3 and Pa 4) and at 12.5 µg/mL and 6.25 µg/mL (ATCC 27853, Pa 2, Pa 4 and Pa 5). No significant positive growth was detected at dilutions < 6.25 µg/mL. similarly, biofilm formation was stimulated at concentration of 12.5 µg/mL (ATCC 27853 and Pa 1) and at 6.25 µg/mL (Pa 4). At concentration of 12.5 µg/mL, ZnO NPs upregulated the expression of LasB ( ATCC 27853, Pa 1 and Pa 4) and LasR and LasI (ATCC 27853 and Pa 1) as well as RhII expression (ATCC 27853, Pa 2 and Pa 4).ConclusionWhen exposed to low ZnO NPs concentrations, P. aeruginosa behaves in a hormetic manner, undergoing positive growth and biofilm formation. These results highlight the importance of understanding the response of P. aeruginosa following exposure to low ZnO NPs concentrations.

Impact of pH and ZnO NPs on the fabricated PVA-PVP/ZnO nanofibers: Morphology, absorption behavior, anticancer, and antibacterial activity

In this study, a cost-effective hydrothermal method was successfully used to synthesize ZnO NPs at different pH levels (8, 10, and 12). Nanofibers were produced from polymeric blends PVA-PVP and PVA-PVP/ZnO nanocomposite precursor through electrospinning. XRD analysis revealed the hexagonal wurtzite structure of the synthesized ZnO NPs, with the dominant crystal plane (101). The impact of pH variation was evident in the increased intensity values of the peaks corresponding to (100), (002), and (101) planes as pH levels rose. The average crystallite size decreased from 31.4 to 27.0 nm using Scherrer's calculation, while the microstrain increased from 11.2 to 12.4 ×10−4 as the pH increased from 8 to 12. As wellas the average particle size of the ZnO NPs decreased from 75.05 to 51.35 nm with increasing pH levels, as depicted in FESEM images. The PVA-PVP/ZnO electrospun nanofibers exhibited smooth surfaces and uniform structures, with average diameters of 80.14, 93.33, and 124.13 nm for pH 8, 10, and 12, respectively. The calculation of the optical energy gap using the ASF approach closely matched Tauc's model, ranging from 3.57 to 3.20 eV. Evaluation of the anticancer activity of the nanofibers against MCF-7 cells showed an increase in cytotoxicity from 18 to 64 % with varying concentrations of ZnO NPs ranging from 6.25 to 100 μg/ml. The highest inhibitory effect (about 16 mm) was observed at pH 12 against gram-positive (Staphylococcus aureus).

Alleviation of arsenic stress in pakchoi by foliar spraying of engineered nanomaterials.

Addressing heavy metal contamination in leafy vegetables is critically important due to its adverse effects on human health. In this study, we investigated the inhibitory effects of foliar spraying with four nanoparticles (CeO2, ZnO, SiO2, and S NPs) on arsenic (As) stress in pakchoi (Brassica rapa var. Chinensis). The findings reveal that foliar application of ZnO NPs at 1 ~ 2.5 mg plant-1 and CeO2 NPs at 5 mg plant-1 significantly reduces As in shoots by 40.9 ~ 47.3% and 39.4%, respectively. Moreover, 5 mg plant-1 CeO2 NPs increased plant height by 6.06% and chlorophyll a (Chla) content by 30.2% under As stress. Foliar spraying of CeO2 NPs at 0.2-5 mg plant-1 also significantly enhanced superoxide dismutase (SOD) activity in shoots by 9.4 ~ 13.9%, lowered H2O2 content by 42.4 ~ 53.25%, and increased root protein contents by 79 ~ 109.2%. CeO2 NPs regulate the As(III)/As(V) ratio, aiding in As efflux from roots and thereby reducing As toxicity to plants. In vitro digestion experiments reveal that the consumption of CeO2 NPs carries the lowest health risk of As. In addition, foliar spraying of ZnO NPs at 1 ~ 2.5 mg plant-1 can suppress plant As uptake by modulating enzyme activity, reducing leaf damage, and enhancing chlorophyll content. The study demonstrates that high CeO2 NP concentrations and suitable ZnO NP concentrations can alleviate As toxicity in pakchoi, consequently reducing human health risks.

Green synthesis and characterization of zinc oxide nanoparticles using Monoon longifolium leave extract for biological applications

The present study deals with the biosynthesis of zinc oxide nanoparticles (ZnO NPs) using the Monoonlongifolium (M. longifolium) leaf extract. The prepared ZnO NPs were characterized by XRD, FTIR, UV–Vis, TGA/DTA, and SEM. The synthesis parameters, such as plant extract volume (10–50 mL), heating duration (15 min), zinc nitrate concentration (1 mM), reaction time (1 h), and temperature (60 °C), were optimized. The synthesized ZnO NPs exhibited significant antibacterial activity against Staphylococcusaureus (22 ± 0.57 mm) and Escherichiacoli (19 ± 1 mm), as well as antifungal activity against Candidaalbicans (21 ± 0.16 mm), as determined by the agar-well-diffusion method. The minimum inhibitory concentration (MIC) of ZnO-NPs against S. aureus (6.25µg/mL) and E. coli (12.5 µg/mL), respectively, while the minimum fungicidal concentration (MFC) was 25 µg/mL against Candidaalbicans. Additionally, the antioxidant activity of the ZnO NPs ranged from 0 to 78% (IC50 = 12.5 μg/mL). These results demonstrate the potential of the synthesized ZnO NPs as effective antibacterial, antifungal, and antioxidant agents.

Optimized electrophoretic zinc oxide coating on SS316L with enhanced hardness and scratch resistance

The major issues in electrophoretic deposition of ZnO coating on SS316L are lack of adhesive strength, control of electrophoretic mobility, and the presence of cracks in the coating. The novelty of the present study is mainly focused on optimizing the electrophoretic deposition parameters by varying the concentration of the ZnO NPs (1.0 g/L and 1.5 g/L) and the applied voltages (30 V and 40 V) to minimize these coating defects. The impact of nanoparticle concentrations and applied voltages on the morphology, roughness, phase composition, functional groups, hardness, surface energy, and scratch resistance of ZnO coatings was analyzed. Various deposition conditions produced different crystal sizes ranging from 16 to 24 nm. Among the deposition conditions, the ZnO-3 coating demonstrated an increased crystal size with decreased microstrain. However, a higher applied voltage of 40 V in the ZnO-3 coating significantly increased the electrophoretic mobility of the NPs, leading to the agglomeration of the NPs and the formation of larger crystals. Furthermore, morphological analysis confirmed uniform distribution and higher deposition rates in the ZnO-2 coating. The ZnO-2 coating deposited at a concentration of ZnO NPs (1.5 g/L) and a lower applied voltage (30 V), exhibited higher coating hardness (216 HV), lower surface roughness (0.207 µm), low surface energy, and better adhesive strength than the other three ZnO coatings. Thus, the optimized electrophoretic coating of ZnO-2 on SS316L emerged as a solution to reduce the cracks, improve the adhesion with better control over electrophoretic mobility.

Efficient chromium removal from leather industrial wastewater in batch experimental study: Green synthesis and characterization of zinc oxide nanoparticles using Ficus benghalensis extracts

The urgent need to address the severe environmental risk posed by chromium-contaminated industrial wastewater necessitates the development of eco-friendly cleanup methodologies. Utilizing the Ficus benghalensis plant extracts, the present study aims to develop green zinc oxide nanoparticles for the removal of Cr metal ions from wastewater. The leaves of Ficus benghalensis, often known as the banyan tree, were used to extract a solution for synthesizing ZnO NPs. These nanoparticles were developed with the goal of efficiently eliminating chromium (Cr) from industrial effluents. Batch studies were carried out to assess the efficiency of these synthesized ZnO NPs in treating leather industrial effluent, with aiming for optimal chromium removal. This involved measuring the nanoparticles' capacity to adsorb Cr ions from wastewater samples by comparing chromium levels before and after treatment. Removal efficiency for Cr was estimated through the batches such as optimization of pH, contact time, initial Cr concentration and sorbent dose of ZnO NPs were of the batches. These synthesized ZnO NPs were found to be successful in lowering chromium levels in wastewater to meet permissible limit. The nanoparticles exhibited their highest absorption capacity, reaching 94 % (46 mg/g) at pH 4, with a contact time of 7 hours with the optimum sorbent dose of 0.6 g/L. Hence, the excellent adsorption capabilities of these nanoparticles, together with their environmentally benign manufacturing technique, provide a long-term and efficient solution for chromium-contaminated wastewater treatment. Its novel nature has the potential to significantly improve the safety and cleanliness of water ecosystems, protecting the both i.e. human health and the environment.

Harnessing Walnut-Based Zinc Oxide Nanoparticles: A Sustainable Approach to Combat the Disease Complex of Meloidogyne arenaria and Macrophomina phaseolina in Cowpea.

Zinc oxide nanoparticles (ZnO NPs) exhibit diverse applications, including antimicrobial, UV-blocking, and catalytic properties, due to their unique structure and properties. This study focused on the characterization of zinc oxide nanoparticles (ZnO NPs) synthesized from Juglans regia leaves and their application in mitigating the impact of simultaneous infection by Meloidogyne arenaria (root-knot nematode) and Macrophomina phaseolina (root-rot fungus) in cowpea plants. The characterization of ZnO NPs was carried out through various analytical techniques, including UV-visible spectrophotometry, Powder-XRD analysis, FT-IR spectroscopy, and SEM-EDX analysis. The study confirmed the successful synthesis of ZnO NPs with a hexagonal wurtzite structure and exceptional purity. Under in vitro conditions, ZnO NPs exhibited significant nematicidal and antifungal activities. The mortality of M. arenaria juveniles increased with rising ZnO NP concentrations, and a similar trend was observed in the inhibition of M. phaseolina mycelial growth. SEM studies revealed physical damage to nematodes and structural distortions in fungal hyphae due to ZnO NP treatment. In infected cowpea plants, ZnO NPs significantly improved plant growth parameters, including plant length, fresh mass, and dry mass, especially at higher concentrations. Leghemoglobin content and the number of root nodules also increased after ZnO NP treatment. Additionally, ZnO NPs reduced gall formation and egg mass production by M. arenaria nematodes and effectively inhibited the growth of M. phaseolina in the roots. Furthermore, histochemical analyses demonstrated a reduction in oxidative stress, as indicated by decreased levels of reactive oxygen species (ROS) and lipid peroxidation in ZnO NP-treated plants. These findings highlight the potential of green-synthesized ZnO NPs as an eco-friendly and effective solution to manage disease complex in cowpea caused by simultaneous nematode and fungal infections.

Effects of particle size on toxicity, bioaccumulation, and translocation of zinc oxide nanoparticles to bok choy (Brassica chinensis L.) in garden soil

The indiscriminate use of zinc oxide nanoparticles (ZnO NPs) in daily life can lead to their release into soil environment. These ZnO NPs can be taken up by crops and translocated to their edible part, potentially causing risks to the ecosystem and human health. In this study, we conducted pot experiments to determine phytotoxicity, bioaccumulation and translocation depending on the size (10 – 30 nm, 80 – 200 nm and 300 nm diameter) and concentration (0, 100, 500 and 1000 mg Zn/kg) of ZnO NPs and Zn ion (Zn2+) in bok choy, a leafy green vegetable crop. After 14 days of exposure, our results showed that large-sized ZnO NPs (i.e., 300 nm) at the highest concentration exhibited greater phytotoxicity, including obstruction of leaf and root weight (42.5 % and 33.8 %, respectively) and reduction of chlorophyll a and b content (50.2 % and 85.2 %, respectively), as well as changes in the activities of oxidative stress responses compared to those of small-sized ZnO NPs, although their translocation ability was relatively lower than that of smaller ones. The translocation factor (TF) values decreased as the size of ZnO NPs increased, with TF values of 0.68 for 10 – 30 nm, 0.55 for 80 – 200 nm, and 0.27 for 300 nm ZnO NPs, all at the highest exposure concentration. Both the results of micro X-ray fluorescence (μ-XRF) spectrometer and bio-transmission electron microscopy (bio-TEM) showed that the Zn elements were mainly localized at the edges of leaves exposed to small-sized ZnO NPs. However, the Zn elements upon exposure to large-sized ZnO NP were primarily observed in the primary veins of leaves in the μ-XRF data, indicating a limitation in their ability to translocate from roots to leaves. This study not only advances our comprehension of the environmental impact of nanotechnology but also holds considerable implications for the future of sustainable agriculture and food safety.

Phytofabrication of biocompatible zinc oxide nanoparticle using Gymnema sylvestre and its potent in vitro antibacterial, antibiofilm, and cytotoxicity against human breast cancer cells (MDA-MB-231).

The increasing incidence of breast cancer and bacterial biofilm in medical devices significantly heightens global mortality and morbidity, challenging synthetic drugs. Consequently, greener-synthesized nanomaterials have emerged as a versatile alternative for various biomedical applications, offering new therapeutic avenues. This study explores the synthesis of biocompatible zinc oxide (ZnONPs) nanoparticles using Gymnema sylvestre and its antibacterial, antibiofilm, and cytotoxic properties. Characterization of ZnONPs inferred that UV-Vis spectra exhibited a sharp peak at 370nm. Fourier transform infrared spectroscopical analysis revealed the presence of active functional groups such as aldehyde, alkyne, cyclic alkene, sulfate, alkyl aryl ether, and Zn-O bonds. X-ray diffraction analysis results confirmed the crystalline nature of the nanoparticle. Scanning electron microscope analysis evidenced hexagonal morphology, and energy-dispersive X-ray analysis confirmed zinc content. High-resolution transmission electron microscope analysis showed hexagonal and rod-shaped ZnONPs with a size of 5nm. Zeta potential results affirmed the stability of nanoparticles. The ZnONPs effectively inhibited gram-positive (18-20mm) than gram-negative (12-18mm) bacterial pathogens with lower bacteriostatic and higher bactericidal values. Biofilm inhibitory property inferred ZnONPs were more effective against gram-positive (38-94%) than gram-negative bacteria (27-86%). The concentration of ZnONPs to exert 50% biofilm-inhibitory is lower against gram-positive bacteria (179.26-203.95μg/mL) than gram-negative bacteria (201.46-236.19μg/mL). Microscopic visualization inferred that at 250μg/mL, ZnONPs strongly disrupted biofilm formation, as evidenced by decreased biofilm density and altered architecture. The cytotoxicity of ZnONPs against breast cancer cells showed a dose-dependent reduction in cell viability with an IC50 value of 19.4µg/mL. AO/EB staining indicated early and late apoptotic cell death of breast cancer cells under fluorescence microscopy. The results of hemolytic activity validated the biocompatibility of the ZnONPs. Thus, the unique properties of the green-synthesized ZnONPs suggest their potential as effective drug carriers for targeted delivery in cancer therapy and the treatment of biofilm-related infections.

Green-synthesized zinc oxide nanoparticles by Enterobacter sp.: unveiling characterization, antimicrobial potency, and alleviation of copper stress in Vicia faba (L.) plants

BackgroundThe biosynthesis of zinc oxide nanoparticles (ZnO NPs) using Enterobacter sp. and the evaluation of their antimicrobial and copper stress (Cu+ 2)-reducing capabilities in Vicia faba (L.) plants. The green-synthesized ZnO NPs were validated using X-ray powder diffraction (XRD); Fourier transformed infrared (FTIR), Ultraviolet-Visible spectroscopy (UV-Vis), Transmission electron microscope (TEM) and scanning electron microscopy (SEM) techniques. ZnO NPs could serve as an improved bactericidal agent for various biological applications. as well as these nanoparticles used in alleviating the hazardous effects of copper stress on the morphological and physiological traits of 21-day-old Vicia faba (L.) plants.ResultsThe results revealed that different concentrations of ZnO NPs (250, 500, or 1000 mg L-1) significantly alleviated the toxic effects of copper stress (100 mM CuSO4) and increased the growth parameters, photosynthetic efficiency (Fv/Fm), and pigments (Chlorophyll a and b) contents in Cu-stressed Vicia faba (L.) seedlings. Furthermore, applying high concentration of ZnO NPs (1000 mg L-1) was the best dose in maintaining the levels of antioxidant enzymes (CAT, SOD, and POX), total soluble carbohydrates, total soluble proteins, phenolic and flavonoid in all Cu-stressed Vicia faba (L.) seedlings. Additionally, contents of Malondialdehyde (MDA) and hydrogen peroxide (H2O2) were significantly suppressed in response to high concentrations of ZnO NPs (1000 mg L-1) in all Cu-stressed Vicia faba (L.) seedlings. Also, it demonstrates strong antibacterial action (0.9 mg/ml) against various pathogenic microorganisms.ConclusionsThe ZnO NPs produced in this study demonstrated the potential to enhance plant detoxification and tolerance mechanisms, enabling plants to better cope with environmental stress. Furthermore, these nanoparticles could serve as an improved bactericidal agent for various biological applications.

Exploring the potential of Nauclea latifolia for sustainable synthesis of ZnO nanoparticles: characterization and antibacterial assessment

The work presents a report on Zinc oxide nanoparticles (ZnO NPs) synthesized through a green approach using Nauclea latifolia fruit extracts, with a view to investigating the prepared nanoparticles for their antimicrobial activities. The ZnO NPs synthesized were characterized using various analytical instruments, including X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Ultraviolet-Visible (UV-Vis) spectroscopy, Dynamic Light Scattering (DLS), and Transmission Electron Microscopy (TEM). The instruments provided valuable information on the characteristics of the Zn ONPs. The antibacterial activities of the synthesized ZnO NPs were evaluated with Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The maximum absorption was observed at 379 nm. The average hydrodynamic size and the polydispersity index (PDI) were measured as 81.77 nm and 0.401, respectively. The nanomaterial has a hexagonal wurtzite structure, and the Zn–O bond was detected at 537 cm–1. The nanoparticles were in the nano range with sizes ranging from 10.02 nm to 28.50 nm. The N. latifolia fruit extract-mediated ZnO NPs showed excellent performance against the two bacteria at all concentrations of ZnO NPs. The highest inhibition zones for E. coli and S. aureus at 8 mg/L of ZnO NPs are 21 and 16 mm, respectively. This study provides valuable insights into an efficient, simple, and environmentally friendly route for synthesizing ZnO NPs with a potential application in the biomedical field.

Inhibitory Effect of the Biosynthesized ZnO Nanoparticles by Musa acuminata Fruits Peels against Pathogenic Bacteria Isolated from Diabetic Foot Ulcer

Zinc Oxide nanoparticles was synthesized by green method with zinc nitrate as precursor and alcoholic extract of Musa acuminata fruits peels as a reducing agent, color changing from white to yellowish -white, which was an indication of the formation of ZnO NPs. Characterization were made by UV-Visible light spectroscopy (Uv-Vis), X-Ray Diffraction (XRD), Atomic force microscopy (AFM) and Field Emission Scan Electron Microscope (FE-SEM), the results showed the sharp UV peaks were at 374 nm , XRD analysis estimated the crystallites sizes in 25.9 nm, AFM was used to determine the average size and forme of the nanoparticles which was 40, 45, and 50 nm, FE- SEM analysis displayed average particles size were 75.6 nm. Clinical of 125 samples were collected from diabetic foot ulcer from patients admitted to Baquba Teaching Hospital during beginning of November 2021 to the end of January 2022, included isolation and diagnosis of 76 isolates of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus epidermidis. Antibacterial activity test was done of ZnO NPs. which was tested toward these isolates. Different concentrations of ZnO NPs. (12.5, 25, 50, 100, 200) mg/ml were examined against pathogenic bacteria , the results showed the highest diameter of inhibition zone against E.coli, K.pneumoniae, P.aeruginosa, S.aureus and S.epidermidis were (28, 27, 31, 29. 26) mm respectively at concentration 200 mg/ ml and the lowest zone at concentration 12.5 mg/ml to the same isolates were (22, 23, 24, 24, 21) mm respectively.