Bioaccumulation of ytterbium oxide nanoparticles insinuate oxidative stress, inflammatory, and pathological lesions in ICR mice

Dynamic interplay of metal and metal oxide nanoparticles with plants: Influencing factors, action mechanisms, and assessment of stimulatory and inhibitory effects

Nanoparticles (NPs) of metals and metal oxides have received increasing attention regarding their characteristic behavior in plant systems. The fate and transport of metal NPs and metal oxide NPs in plants is of emerging concern for researchers because they ultimately become part of the food chain. The widespread use of metal-based NPs (MBNPs) in plants has revealed their beneficial and harmful effects. This review addresses the main factors affecting the uptake, translocation, absorption, bioavailability, toxicity, and accumulation of MBNPs in different plant species. It appraises the mechanism of nanoparticle-plant interaction in detail and provides understanding of the estimation strategies for the associated pros and cons with this interplay. Critical parameters of NPs include, but are not limited to, particle size and shape, surface chemistry, surface charge, concentration, solubility, and exposure route. On exposure to MBNPs, the molecular, physiological, and biochemical reactions of plants have been assessed. We have filled knowledge gaps and answered research questions regarding the positive and negative effects of metal and metal oxide NPs on seed germination, callus induction, growth and yield of plant, nutritional content, antioxidants, and enzymes. Besides, the phytotoxicity, cytotoxicity, genotoxicity, and detoxification studies of MBNPs in plants have been outlined. Furthermore, the recent developments and future perspectives of the two-way traffic of interplay of MBNPs and plants have been provided in this comprehensive review.

Multifaceted roles of silicon nano particles in heavy metals-stressed plants

Heavy metal (HM) contamination has emerged as one of the most damaging abiotic stress factors due to their prominent release into the environment through industrialization and urbanization worldwide. The increase in HMs concentration in soil and the environment has invited attention of researchers/environmentalists to minimize its' impact by practicing different techniques such as application of phytohormones, gaseous molecules, metalloids, and essential nutrients etc. Silicon (Si) although not considered as the essential nutrient, has received more attention in the last few decades due to its involvement in the amelioration of wide range of abiotic stress factors. Silicon is the second most abundant element after oxygen on earth, but is relatively lesser available for plants as it is taken up in the form of mono-silicic acid, Si(OH)4. The scattered information on the influence of Si on plant development and abiotic stress adaptation has been published. Moreover, the use of nanoparticles for maintenance of plant functions under limited environmental conditions has gained momentum. The current review, therefore, summarizes the updated information on Si nanoparticles (SiNPs) synthesis, characterization, uptake and transport mechanism, and their effect on plant growth and development, physiological and biochemical processes and molecular mechanisms. The regulatory connect between SiNPs and phytohormones signaling in counteracting the negative impacts of HMs stress has also been discussed.

Silicon-based nanoparticles for mitigating the effect of potentially toxic elements and plant stress in agroecosystems: A sustainable pathway towards food security

Due to their size, flexibility, biocompatibility, large surface area, and variable functionality nanoparticles have enormous industrial, agricultural, pharmaceutical and biotechnological applications. This has led to their widespread use in various fields. The advancement of knowledge in this field of research has altered our way of life from medicine to agriculture. One of the rungs of this revolution, which has somewhat reduced the harmful consequences, is nanotechnology. A helpful ingredient for plants, silicon (Si), is well-known for its preventive properties under adverse environmental conditions. Several studies have shown how biogenic silica helps plants recover from biotic and abiotic stressors. The majority of research have demonstrated the benefits of silicon-based nanoparticles (Si-NPs) for plant growth and development, particularly under stressful environments. In order to minimize the release of brine, heavy metals, and radioactive chemicals into water, remove metals, non-metals, and radioactive components, and purify water, silica has also been used in environmental remediation. Potentially toxic elements (PTEs) have become a huge threat to food security through their negative impact on agroecosystem. Si-NPs have the potentials to remove PTEs from agroecosystem and promote food security via the promotion of plant growth and development. In this review, we have outlined the various sources and ecotoxicological consequences of PTEs in agroecosystems. The potentials of Si-NPs in mitigating PTEs were extensively discussed and other applications of Si-NPs in agriculture to foster food security were also highlighted.

ZIF-8 Nanoparticles Induce Behavior Abnormality and Brain Oxidative Stress in Adult Zebrafish (Danio rerio)

Zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs) are typical metal-organic framework (MOF) materials and have been intensively studied for their potential application in drug delivery and environmental remediation. However, knowledge of their potential risks to health and the environment is still limited. Therefore, this study exposed female and male zebrafish to ZIF-8 NPs (0, 9.0, and 90 mg L^-1) for four days. Subsequently, variations in their behavioral traits and brain oxidative stress levels were investigated. The behavioral assay showed that ZIF-8 NPs at 90 mg/L could significantly decrease the locomotor activity (i.e., hypoactivity) of both genders. After a ball falling stimulation, zebrafish exposed to ZIF-8 NPs (9.0 and 90 mg L^-1) exhibited more freezing states (i.e., temporary cessations of movement), and males were more sensitive than females. Regardless of gender, ZIF-8 NPs exposure significantly reduced the SOD, CAT, and GST activities in the brain of zebrafish. Correlation analysis revealed that the brain oxidative stress induced by ZIF-8 NPs exposure might play an important role in their behavioral toxicity to zebrafish. These findings highlight the necessity for further assessment of the potential risks of MOF nanoparticles to aquatic species and the environment.

Copper oxide nanoparticles: In vitro and in vivo toxicity, mechanisms of action and factors influencing their toxicology

Copper oxide nanoparticles (CuO NPs) have received increasing interest due to their distinctive properties, including small particle size, high surface area, and reactivity. Due to these properties, their applications have been expanded rapidly in various areas such as biomedical properties, industrial catalysts, gas sensors, electronic materials, and environmental remediation. However, because of these widespread uses, there is now an increased risk of human exposure, which could lead to short- and long-term toxicity. This review addresses the underlying toxicity mechanisms of CuO NPs in cells which include reactive oxygen species generation, leaching of Cu ion, coordination effects, non-homeostasis effect, autophagy, and inflammation. In addition, different key factors responsible for toxicity, characterization, surface modification, dissolution, NPs dose, exposure pathways and environment are discussed to understand the toxicological impact of CuO NPs. In vitro and in vivo studies have shown that CuO NPs cause oxidative stress, cytotoxicity, genotoxicity, immunotoxicity, neurotoxicity, and inflammation in bacterial, algal, fish, rodents, and human cell lines. Therefore, to make CuO NPs a more suitable candidate for various applications, it is essential to address their potential toxic effects, and hence, more studies should be done on the long-term and chronic impacts of CuO NPs at different concentrations to assure the safe usage of CuO NPs.

Zinc oxide nanoparticles as potential hallmarks for enhancing drought stress tolerance in wheat seedlings

Drought is one of the major abiotic stresses which negatively affects plant growth and development. The current study evaluated the effects of drought on the growth, physiology, and biochemical attributes of wheat seedlings; and examined the role of foliar application of ZnO nanoparticles in alleviating drought-induced effects. Two wheat cultivars i.e., Anaj-2017 and FSD-2018 were grown in soil-filled pots and were subjected to 100% field capacity (FC) (well watered) and 50% of FC (drought stress). Whilst different treatments of ZnO nanoparticles spray included no spray, water spray, and 50, 100, and 150 ppm ZnO. Results demonstrated that drought caused a significant reduction in seedling fresh and dry weights, photosynthetic pigmentation, and antioxidant activities compared with a well-watered treatment. Nevertheless, the application of 100 and 150 ppm of ZnO nanoparticles effectively ameliorated the negative effects of drought and enhanced the performance of both cultivars under drought. Data revealed a significant increase in fresh and dry weight of shoot and root with the application of ZnO nanoparticles. A substantial increase of 73.68% and 28.51% in chlorophyll "a" and 26.15% and 50.02% in chlorophyll "b" was recorded with the application of 100 ppm of ZnO nanoparticles in Anaj-2017 and FSD-2018, respectively over control (0 ppm). The application of these nanoparticles also triggered the antioxidant defense system and protected the crop from oxidative damage. Averaged across different stress treatments, application of 150 and 100 ppm of ZnO nanoparticles increased the peroxidase activity by 60% and 72% in FSD-2018, and 15% and 23% in Anaj-2017, respectively compared with no spray. FSD-2018 outperformed Anaj-2017 regarding its overall performance under ZnO treatments and drought conditions. In a nutshell, it can be concluded that ZnO nanoparticles ameliorated the negative impacts of drought by improving the growth, physiology, and antioxidant defense of both wheat cultivars.

Black phosphorus quantum dots cause glucose metabolism disorder and insulin resistance in mice

Black phosphorus quantum dots (BPQDs) are considered to have wide application prospects due to their excellent properties. However, there is no study on the effect of BPQDs on glucose metabolism. In this study, blood glucose was significantly increased when mice were continuously intragastrically administered 0.1 and 1 mg/kg bw BPQDs. The blood glucose level of the mice was elevated from Day 7 to Day 28. BPQD exposure also decreased the area under the curve (AUC) of the oral glucose tolerance test (OGTT). After exposure, the pancreas somatic index was increased. Moreover, the serum insulin and glucagon levels were elevated and the relative area of islet β cells was increased in BPQD-exposed mice, while insulin signaling cascades were reduced in muscle tissues. In summary, our study demonstrated for the first time that BPQD exposure induces glucose disorder and insulin resistance in muscle, which is helpful to understand the biosafety of black phosphorus nanomaterials and promote the sustainable development of nanotechnology.

Green synthesis of metal-based nanoparticles for sustainable agriculture

The large-scale use of conventional pesticides and fertilizers has put tremendous pressure on agriculture and the environment. In recent years, nanoparticles (NPs) have become the focus of many fields due to their cost-effectiveness, environmental friendliness and high performance, especially in sustainable agriculture. Traditional NPs manufacturing methods are energy-intensive and harmful to environment. In contrast, synthesizing metal-based NPs using plants is similar to chemical synthesis, except the biological extracts replace the chemical reducing agent. This not only greatly reduces the used of traditional chemicals, but also produces NPs that are more economical, efficient, less toxic, and less polluting. Therefore, green synthesized metal nanoparticles (GS-MNPs) are widely used in agriculture to improve yields and quality. This review provides a comprehensive and detailed discussion of GS-MNPs for agriculture, highlights the importance of green synthesis, compares the performance of conventional NPs with GS-MNPs, and highlights the advantages of GS-MNPs in agriculture. The wide applications of these GS-MNPs in agriculture, including plant growth promotion, plant disease control, and heavy metal stress mitigation under various exposure pathways, are summarized. Finally, the shortcomings and prospects of GS-MNPs in agricultural applications are highlighted to provide guidance to nanotechnology for sustainable agriculture.

Identification of ceRNA network to explain the mechanism of cognitive dysfunctions induced by PS NPs in mice

Plastics breaking down of larger plastics into smaller ones (microplastics and nanoplastic) as potential threats to the ecosystem. Previous studies demonstrate that the central nervous system (CNS) is a vulnerable target of nanoplastics. However, the potentially epigenetic biomarkers of nanoplastic neurotoxicity in rodent models are still unknown. The present research aimed to determine the role of competing endogenous RNA (ceRNA) in the process of polystyrene nanoplastics (PS NPs) exposure-induced nerve injury. The study was designed to investigate whether 25 nm PS NPs could cause learning dysfunction and to elucidate the underlying mechanisms in mice. A total of 40 mice were divided into 4 groups and were exposed to PS NPs (0, 10, 25, 50 mg/kg). Chronic toxicity was introduced in mice by administration of oral gavage for 6 months. The evaluation included assessment of their behavior, pathological investigation and determination of the levels of reactive oxygen species (ROS) and DNA damage. RNA-Seq was performed to detect the expression levels of circRNAs, miRNAs and mRNAs in PFC samples of mice treated with 0 and 50 mg/kg PS NPs. The results indicated that exposure of mice to PS NPs caused a dose-dependent cognitive decline. ROS levels and DNA damage were increased in the PFC following exposure of the mice to PS NPs. A total of 987 mRNAs, 29 miRNAs and 67 circRNAs demonstrated significant differences between the 0 and 50 mg/kg PS NPs groups. Functional enrichment analyses indicated that PS NPs may induce major injury in the synaptic function. A total of 96 mRNAs, which were associated with synaptic dysfunction were identified. A competing endogenous RNA (ceRNA) network containing 27 circRNAs, 19 miRNAs and 35 synaptic dysfunction-related mRNAs was constructed. The present study provided insight into the molecular events associated with nanoplastic toxicity and induction of cognitive dysfunction.

Modeling potential distribution of newly recorded ant, Brachyponera nigrita using Maxent under climate change in Pothwar region, Pakistan

Climate change has been discussed as to exert shifts in geographical range of plants, animals or insect species by increasing, reducing or shifting its appropriate climatic habitat. Globally, Pakistan has been ranked at 5^th position on the list of countries most vulnerable to climate change in 2020. Climate change has resulted in the losses of biodiversity and alteration in ecosystem as a result of depletion of natural habitats of species in Pakistan as well as in the world. Ants have been regarded as indicators of environmental change and ecosystem processes. Brachyponera nigrita (Emery, 1895) was reported for the first time from Pakistan (Pothwar region). Objective of our studies was to model geographic distribution of newly recorded ant species, B. nigrita based on two representative concentration pathways (RCP) (RCP4.5 and RCP8.5) for 2050s using maximum entropy model (Maxent) in Pakistan. In modeling procedure, 21occurrence records and 8 variables namely Bio4 (Temperature seasonality), Bio8 (Mean temperature of wettest quarter), Bio10 (Mean temperature of warmest quarter), Bio12 (Annual precipitation), Bio13 (Precipitation of wettest month), Bio15 (Precipitation seasonality), Bio17 (Precipitation of driest quarter) and Bio18 (Precipitation of warmest quarter) were used to determine the current and future distributions. Performance of the model was evaluated using AUC (area under curves) values, partial ROC, omission rates (E = 5%) and AICc (Model complexity).The results showed the average AUC value of the model was 0.930, which indicated that the accuracy of the model was excellent. The jackknife test also showed that Bio4, Bio18, Bio17 and Bio15 contributed 98% for the prediction of potential distribution of the species as compared to all other variables. Maxent results indicated that distribution area of B. nigrita under future predicted bioclimatics 2050 (RCP 4.5 and RCP8.5) would be increased in various localities of Pakistan as compared to its current distribution. In Pothwar region, moderately suitable and highly suitable areas of this species would increase by 505.932321km²and 572.118421km²as compared to current distribution under 2050 (RCP 4.5), while under 2050 (RCP 8.5), there would be an increase of 6427.2576km²and 3765.140493km² respectively in moderately suitable and highly suitable areas of B. nigrita. This species was associated with termites, collembolans and larval stages of different insects. White eggs, creamy white pupae and many workers of this species were observed in a variety of habitats. Unknown nesting ecology, species identification characters supported with micrographs has been given which will help researchers for further ecological studies.

Sustainable Amelioration of Heavy Metals in Soil Ecosystem: Existing Developments to Emerging Trends

The consequences of heavy metal contamination are progressively degrading soil quality in this modern period of industry. Due to this reason, improvement of the soil quality is necessary. Remediation is a method of removing pollutants from the root zone of plants in order to minimize stress and increase yield of plants grown in it. The use of plants to remove toxins from the soil, such as heavy metals, trace elements, organic chemicals, and radioactive substances, is referred to as bioremediation. Biochar and fly ash techniques are also studied for effectiveness in improving the quality of contaminated soil. This review compiles amelioration technologies and how they are used in the field. It also explains how nanoparticles are becoming a popular method of desalination, as well as how they can be employed in heavy metal phytoremediation.

Uptake and Accumulation of Nano/Microplastics in Plants: A Critical Review

The ubiquitous presence of microplastics (MPs) and nanoplastics (NPs) in the environment is an undeniable and serious concern due to their higher persistence and extensive use in agricultural production. This review highlights the sources and fate of MPs and NPs in soil and their uptake, translocation, and physiological effects in the plant system. We provide the current snapshot of the latest reported studies with the majority of literature spanning the last five years. We draw attention to the potential risk of MPs and NPs in modern agriculture and their effects on plant growth and development. We also highlight their uptake and transport pathways in roots and leaves via different exposure methods in plants. Conclusively, agricultural practices, climate changes (wet weather and heavy rainfall), and soil organisms play a major role in transporting MPs and NPs in soil. NPs are more prone to enter plant cell walls as compared to MPs. Furthermore, transpiration pull is the dominant factor in the plant uptake and translocation of plastic particles. MPs have negligible negative effects on plant physiological and biochemical indicators. Overall, there is a dire need to establish long-term studies for a better understanding of their fate and associated risks mechanisms in realistic environment scenarios for safe agricultural functions.

Bio-interaction of nano and bulk lanthanum and ytterbium oxides in soil system: Biochemical, genetic, and histopathological effects on Eisenia fetida

The massive application of rare earth elements (REEs) in electronic industries cause their inevitable release into the environment; however, its effects on soil biota remain largely unaddressed. We investigated the E. fetida detoxification potential of nano and bulk La₂O₃ and Yb₂O₃ and their potential impact on biochemical and genetic markers at 50, 100, 200, 500 and 1000 mg kg^-1 concentration. We found that earthworms bioremediate 3-15% La₂O₃ and Yb₂O₃ contaminated soil at low and medium levels, while this potential was limited at higher levels. Nano and bulk La₂O₃ and Yb₂O₃ treatment induced neurotoxicity in earthworm by inhibiting acetylcholinesterase by 49-65% and 22-36% at 500 and 1000 mg kg^-1, respectively. Nano La₂O₃ proved to be highly detrimental, mainly through oxidative stress and subsequent failure of antioxidant system. Nano La₂O₃ and Yb₂O₃ at 100 mg kg^-1 significantly down-regulated the expression of annetocin mRNA in the parental and progeny earthworms by 50% and 20%, which is crucial for earthworm reproduction. Similarly, expression level of heat shock protein 70 (HSP70) and metallothionein was significantly upregulated in both generations at medium exposure level. Histological observations showed that nano REEs at 200 mg kg^-1 induced drastic changes in the intestinal epithelium and typhlosole of E. fetida. To date, our results enhance the understanding of interaction between REEs and earthworms.

In vitro acaricidal activity of green synthesized nickel oxide nanoparticles against the camel tick, Hyalomma dromedarii (Ixodidae), and its toxicity on Swiss albino mice

The green synthesized nanoparticles have been determined as a novel pesticide against arthropod pests. This study was designed to evaluate the in vitro acaricidal activity of green synthesized nickel oxide nanoparticles (NiO NPs) using aqueous extract of Melia azedarach ripened fruits against different developmental stages of the camel tick Hyalomma dromedarii in addition to their toxic effect on laboratory animals. The synthesized NiO NPs were characterized by UV-visible (UV-Vis) spectroscopy, Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The UV-Vis spectra of the NiO NPs showed an absorption peak at 307 nm. FTIR analysis showed the possible functional groups used for capping and stabilization of NiO NPs with strong bands at 3416.2 and 1626.6 cm^-1. The SEM images of the NiO NPs exhibited a size ranging from 21 to 35 nm. The immersion test was used for the in vitro application of the synthesized NiO NPs on the various tick stages (egg, nymph, larva, and adult). Mortality percentages and LC₅₀ values of each tick stage were calculated. The oviposition and hatchability of the engorged females were monitored for the survived tick after treatment. The LC₅₀ values for NiO NPs on embryonated eggs, larvae, and engorged nymphs were 5.00, 7.15, and 1.90 mg/mL, respectively. The egg productive index (EPI), egg number, and hatchability (%) were lower in females treated with the NiO NPs than in control ticks. The toxicity of the NiO NPs on laboratory animals was also investigated using Swiss albino mice by oral dose of 500 mg/kg/day administration for five consecutive days. The hematological, biochemical, and histopathological changes were evaluated. The hematological analysis showed significant increase in the level of white blood cells (WBC) and hemoglobin (Hb). Biochemical analysis showed non-significant decrease in alkaline phosphatase (ALP) and alanine amino transferase (ALT). We concluded that NiO NPs have a significant acaricidal activity as demonstrated on eggs, larvae, engorged nymphs, and fully fed females of H. dromedarii. From a toxicological point of view further in vivo investigations are needed to determine the mechanism of toxic effect of NiO NPs.

Application of Nanoparticles Alleviates Heavy Metals Stress and Promotes Plant Growth: An Overview

Nanotechnology is playing a significant role in addressing a vast range of environmental challenges by providing innovative and effective solutions. Heavy metal (HM) contamination has gained considerable attention in recent years due their rapidly increasing concentrations in agricultural soil. Due to their unique physiochemical properties, nanoparticles (NPs) can be effectively applied for stress alleviation. In this review, we explore the current status of the literature regarding nano-enabled agriculture retrieved from the Web of Science databases and published from January 2010 to November 2020, with most of our sources spanning the past five years. We briefly discuss uptake and transport mechanisms, application methods (soil, hydroponic and foliar), exposure concentrations, and their impact on plant growth and development. The current literature contained sufficient information about NPs behavior in plants in the presence of pollutants, highlighting the alleviation mechanism to overcome the HM stress. Furthermore, we present a broad overview of recent advances regarding HM stress and the possible mechanism of interaction between NPs and HM in the agricultural system. Additionally, this review article will be supportive for the understanding of phytoremediation and micro-remediation of contaminated soils and also highlights the future research needs for the combined application of NPs in the soil for sustainable agriculture.