Nanoparticles: Properties, applications and toxicities

Reactive oxygen species

The present study investigates ameliorative effect of nitric oxide (NO) against zinc oxide nanoparticles (ZnONPs) phytotoxicity in wheat seedlings. ZnONPs exposure hampered growth of wheat seedlings which was coincided with reduced photosynthetic efficiency (Fv/Fm and qP) due to increased accumulation of zinc (Zn) in xylem and phloem saps. However, SNP supplementation has partially mitigated the ZnONPs-mediated toxicity by modulation of photosynthetic activity and Zn accumulation in xylem and phloem sap. Further, the results reveal that ZnONPs treatments enhanced level of hydrogen peroxide (H2O2) and hence lipid peroxidation (as malondialdehyde; MDA) due to severely inhibited activities of the ascorbate-glutatione cycle (AsA-GSH) enzymes: ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR), and its associated metabolites: reduced ascorbate and glutathione. In contrast to this, the addition of SNP together with ZnONPs maintained the cellular functioning of the AsA-GSH cycle properly, hence lesser damage was noticed in comparison to ZnONPs treatments alone. The protective effect of SNP against ZnONPs toxicity on fresh weight (growth) can be reversed by 2-(4carboxy-2-phenyl)-4,4,5,5-tetramethyl- imidazoline-1-oxyl-3-oxide, a NO scavenger, suggesting role of NO released from SNP in ameliorating ZnONPs toxicity. Overall the results of the present study have shown about implication of NO in the reducing ZnONPs toxicity through the regulation of accumulation of Zn, and functioning of the AsA-GSH cycle.

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Nitric Oxide Ameliorates Zinc Oxide Nanoparticles Phytotoxicity in Wheat Seedlings: Implication of the Ascorbate-Glutathione Cycle.

Iron oxide nanoparticles: Diagnostic, therapeutic and theranostic applications.

Metal nanoparticles synthesis: An overview on methods of preparation, advantages and disadvantages, and applications

Recently, iron oxide nanoparticles (NPs) have attracted much consideration due to their unique properties, such as superparamagnetism, surface-to-volume ratio, greater surface area, and easy separation methodology. Various physical, chemical, and biological methods have been adopted to synthesize magnetic NPs with suitable surface chemistry. This review summarizes the methods for the preparation of iron oxide NPs, size and morphology control, and magnetic properties with recent bioengineering, commercial, and industrial applications. Iron oxides exhibit great potential in the fields of life sciences such as biomedicine, agriculture, and environment. Nontoxic conduct and biocompatible applications of magnetic NPs can be enriched further by special surface coating with organic or inorganic molecules, including surfactants, drugs, proteins, starches, enzymes, antibodies, nucleotides, nonionic detergents, and polyelectrolytes. Magnetic NPs can also be directed to an organ, tissue, or tumor using an external magnetic field for hyperthermic treatment of patients. Keeping in mind the current interest in iron NPs, this review is designed to report recent information from synthesis to characterization, and applications of iron NPs.

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Synthesis, characterization, applications, and challenges of iron oxide nanoparticles

Nanoparticles (NPs) have diverse properties in comparison to respective chemicals due to structure, surface area ratio, morphology, and reactivity. Toxicological effects of metallic NPs to organisms including plants have been reported. However, to the authors’ knowledge there is no report on the effect of NPs on in vitro culture of plant explants. In this study, ZnO NPs at 500-1500 mg/L badly affected Brassica nigra seed germination and seedling growth and raised antioxidative activities and antioxidants concentrations. On the other hand, culturing the stem explants of B. nigra on Murashige and Skoog (MS) medium in presence of low concentration of ZnO NPs (1-20 mg/L) produced white thin roots with thick root hairs. At 10 mg/L ZnO NPs shoots emergence was also observed. The developed calli/roots showed 79% DPPH (2,2-diphenyl-1-picryl hydrazyl) radical scavenging activity at 10 mg/L. While total antioxidant and reducing power potential were also significantly different in presence of ZnO NPs. Non enzymatic antioxidative molecules, phenolics (up to 0.15 µg GAE/mg FW) and flavonoids (up to 0.22 µg QE/mg FW), also raised and found NPs concentration dependent. We state that ZnO NPs may induce roots from explants cultured on appropriate medium and can be cultured for production of valuable secondary metabolites.

/pdf/effect-of-zno-nanoparticles-on-brassica-nigra-seedlings-and-2pb5gykxzj.pdf

Effect of ZnO Nanoparticles on Brassica nigra Seedlings and Stem Explants: Growth Dynamics and Antioxidative Response.

Interests associated with nanoparticles (NPs) are budding due to their toxicity to living species. The lethal effect of NPs depends on their nature, size, shape, and concentration. Present investigation reports that CuO NPs badly affected Brassica nigra seed germination and seedling growth parameters. However, variation in antioxidative activities and nonenzymatic oxidants is observed in plantlets. Culturing the leaf and stem explants on MS medium in presence of low concentration of CuO NPs (1–20 mg l−1) produces white thin roots with thick root hairs. These roots also show an increase in DPPH radical scavenging activity (up to 80 % at 10 mg l−1), total antioxidant, and reducing power potential (maximum in presence of 10 mg l−1 CuO NPs in the media). Nonenzymatic antioxidative molecules, phenolics and flavonoids, are observed elevated but NPs concentration dependent. We can conclude that CuO NPs can induce rooting from plant explants cultured on appropriate medium. These roots can be explored for the production of active chemical constituents.

CuO Nanoparticles Inhibited Root Growth from Brassica nigra Seedlings but Induced Root from Stem and Leaf Explants.

To investigate metal nanoparticle-induced phytotoxicity, Brassica nigra seeds were exposed to 50–1000 mg L−1 ZnO nanoparticles in culture media and 100–1000 mg kg−1 in soil. Plant length and weight...

Physiological and antioxidative response of Brassica nigra (L.) to ZnO nanoparticles grown in culture media and soil

Black mustard (Brassica nigra) was grown in pots amended with 41 nm ZnO (200-600 mg/kg soil) and 47 nm CuO (12.5-50 mg/kg soil) nanoparticles (NPs) to analyze growth response and yield characteristics. B. nigra seed germination was not affected by CuO NPs, but significant toxicity was observed by ZnO NP treatment. Both NPs significantly increased the growth profile of B. nigra, i.e., the stem height, number of leaves, average leaf area, number of branches, and number of nodes per plant. Application of ZnO and CuO NPs brought a significant dose-dependent decrease in primary root length; however, the number of secondary roots increased in the presence of CuO NPs. The average number of flowers and pods per plant significantly increased in the presence of CuO NPs. The seed yield, average seed weight per plant, and seed diameter parameters were observed to be better in the presence of CuO NPs as compared with ZnO NPs. Total protein contents and glucosinolates increased in the seeds grown in the NP-amended soil, while total oil contents decreased. Oil analysis depicted that oleic acid and linolenic acid percentage decreased while erucic acid percentage increased in seeds in the presence of both NPs in the soil. An atomic absorption spectrophotometer showed accumulation of Cu and Zn in B. nigra in the following order: root > stem > leaves > seeds. The study concludes that CuO and ZnO NPs have detrimental effect on the B. nigra plant and yield. The release of NPs and type of metal in NPs might also have a positive effect on the plant; however, their concentration in the soil also matters.

https://pubs.acs.org/doi/pdf/10.1021/acsomega.0c00030

Hira Zafar

Papers

Synthesis, characterization, applications, and challenges of iron oxide nanoparticles

Effect of ZnO Nanoparticles on Brassica nigra Seedlings and Stem Explants: Growth Dynamics and Antioxidative Response.

CuO Nanoparticles Inhibited Root Growth from Brassica nigra Seedlings but Induced Root from Stem and Leaf Explants.

Physiological and antioxidative response of Brassica nigra (L.) to ZnO nanoparticles grown in culture media and soil

CuO and ZnO Nanoparticle Application in Synthetic Soil Modulates Morphology, Nutritional Contents, and Metal Analysis of Brassica nigra.