Interaction of titanium dioxide and zinc oxide nanoparticles induced cytogenotoxicity in Allium cepa

Biogenic Synthesis of Zinc Oxide Nanoparticles Mediated by the Extract of Terminalia catappa Fruit Pericarp and Its Multifaceted Applications

Zinc oxide nanoparticles (ZnO-NPs) were biosynthesized by using the pericarp aqueous extract from Terminalia catappa Linn. These NPs were characterized using various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM), and XRD studies of the nanoparticles reported mean size as 12.58 nm nanocrystals with highest purity. Further SEM analysis emphasized the nanoparticles to be spherical in shape. The functional groups responsible for capping and stabilizing the NPs were identified with FTIR studies. DLS studies of the synthesized NPs reported ζ potential as -10.1 mV and exhibited stable colloidal solution. These characterized ZnO-NPs were evaluated for various biological applications such as antibacterial, antifungal, antioxidant, genotoxic, biocompatibility, and larvicidal studies. To explore its multidimensional application in the field of medicine. NPs reported a potential antimicrobial activity at a concentration of 200 μg/mL against bacterial strains in the decreasing order of Streptococcus pyogenes > Streptococcus aureus > Streptococcus typhi > Streptococcus aeruginosa and against the fungi Candida albicans. In vitro studies of RBC hemolysis with varying concentrations of NPs confirm their biocompatibility with IC50 value of 211.4 μg/mL. The synthesized NPs' DPPH free radical scavenging activity was examined to extend their antioxidant applications. The antiproliferation and genetic toxicity were studied with meristematic cells of Allium cepa reported with mitotic index (MI index) of 1.2% at the concentration of 1000 μg/mL. NPs exhibited excellent Larvicidal activity against Culex quinquefasciatus larvae with the highest mortality rate as 98% at 4 mg/L. Our findings elicit the therapeutic potentials of the synthesized zinc oxide NPs.

Zinc oxide nanoparticles (ZnONPs) influenced seed development, grain quality, and remobilization by affecting the transcription of microRNA 171 (miR171), miR156, NAM, and SUT genes in wheat (Triticum aestivum): a biological advantage and risk assessment study

Limited studies have been conducted on the role of microRNAs (miRs) and transcription factors in regulating plant cell responses to nanoparticles. This study attempted to address whether the foliar application of zinc oxide nanoparticles (ZnONPs; 0, 10, 25, and 50 mgL^-1) can affect miRs, gene expression, and wheat grain quality. The seedlings were sprayed with ZnONPs (0, 10, 25, and 50 mgL^-1) or bulk counterpart (BZnO) five times at 72 h intervals. The application of ZnONPs at 10 mgL^-1 increased the number of spikelets and seed weight, while the nano-supplement at 50 mgL^-1 was accompanied by severe restriction on developing spikes and grains. ZnONPs, in a dose-dependent manner, transcriptionally influenced miR156 and miR171. The expression of miR171 showed a similar trend to that of miR156. The ZnONPs at optimum concentration upregulated the NAM transcription factor and sucrose transporter (SUT) at transcriptional levels. However, the transcription of both NAM and SUT genes displayed a downward trend in response to the toxic dose of ZnONPs (50 mgL^-1). Utilization of ZnONPs increased proline and total soluble phenolic content. Monitoring the accumulation of carbohydrates, including fructan, glucose, fructose, and sucrose, revealed that ZnONPs at 10 mgL^-1 modified the source/sink communication and nutrient remobilization. The molecular and physiological data revealed that the expression of miR156 and miR171 is tightly linked to seed grain development, remobilization of carbohydrates, and genes involved in nutrient transportation. This study establishes a novel strategy for obtaining higher yields in crops. This biological risk assessment investigation also displays the potential hazard of applying ZnONPs at the flowering developmental phase.

Reduced Genotoxicity of Gold Nanoparticles With Protein Corona in Allium cepa

Increased usage of gold nanoparticles (AuNPs) in biomedicine, biosensing, diagnostics and cosmetics has undoubtedly facilitated accidental and unintentional release of AuNPs into specific microenvironments. This is raising serious questions concerning adverse effects of AuNPs on off-target cells, tissues and/or organisms. Applications utilizing AuNPs will typically expose the nanoparticles to biological fluids such as cell serum and/or culture media, resulting in the formation of protein corona (PC) on the AuNPs. Evidence for PC altering the toxicological signatures of AuNPs is well studied in animal systems. In this report, we observed significant genotoxicity in Allium cepa root meristematic cells (an off-target bioindicator) treated with high concentrations (≥100 µg/ml) of green-synthesized vanillin capped gold nanoparticles (VAuNPs). In contrast, protein-coated VAuNPs (PC-VAuNPs) of similar concentrations had negligible genotoxic effects. This could be attributed to the change in physicochemical characteristics due to surface functionalization of proteins on VAuNPs and/or differential bioaccumulation of gold ions in root cells. High elemental gold accumulation was evident from µ-XRF mapping in VAuNPs-treated roots compared to treatment with PC-VAuNPs. These data infer that the toxicological signatures of AuNPs are influenced by the biological route that they follow to reach off-target organisms such as plants. Hence, the current findings highlight the genotoxic risk associated with AuNPs, which, due to the enhanced utility, are emerging as new pollutants. As conflicting observations on the toxicity of green-synthesized AuNPs are increasingly reported, we recommend that detailed studies are required to investigate the changes in the toxicological signatures of AuNPs, particularly before and after their interaction with biological media and systems.

Synthesis of a Novel, Biocompatible and Bacteriostatic Borosiloxane Composition with Silver Oxide Nanoparticles

Microbial antibiotic resistance is an important global world health problem. Recently, an interest in nanoparticles (NPs) of silver oxides as compounds with antibacterial potential has significantly increased. From a practical point of view, composites of silver oxide NPs and biocompatible material are of interest. A borosiloxane (BS) can be used as one such material. A composite material combining BS and silver oxide NPs has been synthesized. Composites containing BS have adjustable viscoelastic properties. The silver oxide NPs synthesized by laser ablation have a size of ~65 nm (half-width 60 nm) and an elemental composition of Ag₂O. The synthesized material exhibits strong bacteriostatic properties against E. coli at a concentration of nanoparticles of silver oxide more than 0.01%. The bacteriostatic effect depends on the silver oxide NPs concentration in the matrix. The BS/silver oxide NPs have no cytotoxic effect on a eukaryotic cell culture when the concentration of nanoparticles of silver oxide is less than 0.1%. The use of the resulting composite based on BS and silver oxide NPs as a reusable dry disinfectant is due to its low toxicity and bacteriostatic activity and its characteristics are not inferior to the medical alloy nitinol.

Smart nanomaterial and nanocomposite with advanced agrochemical activities

Conventional agriculture solely depends upon highly chemical compounds that have negatively ill-affected the health of every living being and the entire ecosystem. Thus, the smart delivery of desired components in a sustainable manner to crop plants is the primary need to maintain soil health in the upcoming years. The premature loss of growth-promoting ingredients and their extended degradation in the soil increases the demand for reliable novel techniques. In this regard, nanotechnology has offered to revolutionize the agrotechnological area that has the imminent potential over conventional agriculture and helps to reform resilient cropping systems withholding prominent food security for the ever-growing world population. Further, in-depth investigation on plant-nanoparticles interactions creates new avenues toward crop improvement via enhanced crop yield, disease resistance, and efficient nutrient utilization. The incorporation of nanomaterial with smart agrochemical activities and establishing a new framework relevant to enhance efficacy ultimately help to address the social acceptance, potential hazards, and management issues in the future. Here, we highlight the role of nanomaterial or nanocomposite as a sustainable as well stable alternative in crop protection and production. Additionally, the information on the controlled released system, role in interaction with soil and microbiome, the promising role of nanocomposite as nanopesticide, nanoherbicide, nanofertilizer, and their limitations in agrochemical activities are discussed in the present review.

Novel Fabrication of Zein-Soluble Soybean Polysaccharide Nanocomposites Induced by Multifrequency Ultrasound, and Their Roles on Microstructure, Rheological Properties and Stability of Pickering Emulsions

In this work, soluble soybean polysaccharides (SSPS) were employed together with multifrequency ultrasound to fabricate zein nanocomposites which were conducive to enhancing the stability of high internal phase emulsions (HIPEs). Compared with non-ultrasonic treated zein colloidal particle samples (132.23 ± 0.85 nm), the zein nanoparticles samples induced by dual-frequency ultrasound exhibited a smaller particle size (114.54 ± 0.23 nm). Furthermore, the particle size of the zein composite nanoparticles (256.5 ± 4.81) remarkably increased with SPSS coating, consequently leading to larger fluorescence intensity together with lower zeta-potential (-21.90 ± 0.46 mv) and surface hydrophobicity (4992.15 ± 37.28). Meanwhile, zein-SSPS composite nanoparticles induced by DFU showed remarkably enhanced thermal stability. Fourier transform infrared (FTIR) spectroscopy and Circular dichroism (CD) spectroscopy were also used to characterize zein-SSPS composite nanoparticles. The results confirmed that DFU combined with SSPS treatment significantly increased β-sheets (from 12.60% ± 0.25 b to 21.53% ± 0.37 c) and reduced α-helix content (34.83% ± 0.71 b to 23.86% ± 0.66 a) remarkably. Notably, HIPEs prepared from zein-SSPS nanocomposites induced by dual-frequency simultaneous ultrasound (DFU) at 40/60 kHz showed better storage stability. HIPEs stabilized by DFU induced zein-SSPS nanoparticles exhibited higher storage modulus (G') and loss modulus (G″), leading to lower fluidity, together with better stability contributing to the water-binding capacity and three-dimensional (3D) network structure of the HIPEs emulsion. The findings of this study indicate that this method can be utilized and integrated to further extend the application of zein and SSPS and explore HIPEs.

Effect of glutamic acid on the preparation and characterization of Pickering emulsions stabilized by zein

In this study, glutamic acid and zein were utilized to prepare colloidal nanoparticles as stabilizers for Pickering emulsions. The effect of the ratio of glutamic acid to zein on the stability, zeta potential, particle size, morphology, and structure of colloidal nanoparticles was studied. The results showed that zein and glutamic acid combined in the form of noncovalent bonds, which changed the characteristics of the zein. In addition, colloidal particles aggregation was induced by glutamic acid, which altered the distribution of droplets in the emulsion, and increased the adsorption of proteins on the surface of the oil droplets, as reflected by the analysis of the size, microstructure, rheological behaviours, and driving force of the Pickering emulsion. Hydrophobic interactions and electrostatic interactions were the main driving forces for the formation of colloidal particles, which was determined by driving force analysis and the change of the zeta potential.

Effect of the duration of use of aluminum cookware on its metal leachability and cytogenotoxicity in Allium cepa assay

Aluminum cookware are widely used in many parts of the world. Data is increasing on the leaching of toxic metals from aluminum cookware into food and drink. In the present study, cytogenotoxicity of water boiled in three different aluminum pots (new, 3-year-old, and 6-year-old) in onion root tip's dividing cells was evaluated using the Allium cepa assay. The concentrations of Pb, As, Cd, Cu, Ni, and Al in the samples were also analyzed. Onion bulbs were grown in the boiled water samples, while tap water served as the control. Cytological and genetic analyses were carried out after 48 h, while analysis of inhibition of root length was carried out after 72 h. The results showed a significant (p < 0.05) cell proliferation and root growth inhibition compared with the control, which is dependent on the duration of use of the aluminum pots. The boiled water samples also caused modification of the root morphology as well as chromosomal aberrations which include sticky chromosomes, anaphase bridge, and disturbed spindle. The highest cytogenotoxicity was observed in the 6-year-old aluminum pot and the least in the new aluminum pot. Pb, As, Cd, Cu, Ni, and Al analyzed in the samples, with the highest concentrations in the 6-year-old aluminum pot, were believed to be responsible for the cytogenotoxicity observed in the A. cepa assay. The data of this study are indications that the aluminum pot-boiled water contains substances with the potential to be cytotoxic and cause mutations in somatic cells of A. cepa.

Titanium dioxide nanoparticles-induced cytogenotoxicity and alterations in haematological indices of Clarias gariepinus (Burchell, 1822)

The application of titanium dioxide (TiO₂) nanoparticles (NPs) in the manufacturing of consumer products has increased tremendously and with the potential to induce deleterious effects on aquatic biota. There have been reports on metal oxide NP toxicity in aquatic organisms, however, information on cytotoxicity and genotoxicity of TiO₂ NPs on the African catfish, Clarias gariepinus, is scarce. In this study, we investigated the genotoxicity and haematotoxicity of TiO₂ NPs in C. gariepinus using the micronucleus (MN) assay and haematological analysis, respectively. Juvenile C. gariepinus were exposed to 6.25, 12.5, 25.0, 50.0 and 100.0 mg L^-1 concentrations of TiO₂ NPs for 7 and 28 days. Benzene (0.05 mL L^-1) and dechlorinated tap water were used as positive and negative controls, respectively. Data of the MN showed a significant (p < 0.05) concentration-dependent increase in the frequency of MN at both exposure periods in comparison to negative control. Red blood cells, haematocrit, platelets and heterophils significantly reduced with an increased mean corpuscular haemoglobin concentration and lymphocytes at the 7-day exposure period, while in the 28-day exposure period, mean cell volume, mean corpuscular haemoglobin and lymphocytes had a significant increase in comparison with the negative control. This study indicates that TiO₂ NPs induced cytogenetic and haematological alterations in C. gariepinus and is of relevance in biodiversity and aquatic health management.