Concentrations Of TiO2 NPs Research Articles

Biogenic Titanium Dioxide Nanoparticles Ameliorate the Effect of Salinity Stress in Wheat Crop

Crop productivity worldwide is being hampered by salt stress. Nanotechnology and its applications in agriculture are noteworthy and fruitful. The current work investigates the potential significance of TiO2 NPs in alleviating salt stress in wheat cultivars. TiO2 NPs were prepared by green synthesis; their characterizations were carried out by UV–visible spectroscopy, SEM, and EDX. In the greenhouse control condition, different concentrations of salt (NaCl) with and without TiO2 NPs were administered to wheat crops. Plants treated with TiO2 NPs showed an enhanced germination rate, morphological, and metabolic profiling with and without salt stress. Different concentrations of TiO2 NPs (25, 50, 75, and 100 µg/mL) and salt solutions (NaCl 50, 100, and 150 mM) were used. TiO2 NP concentrations of 25 µg/mL and 50 µg/mL improved the germination attributes, physio-morphic parameters: plant length, the fresh and dry weight of plants, the number of leaves, the leaf area, the RWC, the MSI, and different chlorophyll contents at all saline conditions. These two concentrations also enhanced the biochemical attributes: free amino acids, soluble sugar content, proline content, SOD, and POD, of wheat varieties at all salinity levels. Wheat subjected to salt stress responded best to the application of TiO2 NPs at a concentration of 50 µg/mL. However, the highest concentrations (75 and 100 µg/mL) of TiO2 NPs showed detrimental effects on germination, agronomic, physiological, and biochemical attributes, and caused stress in both wheat varieties (Pirsabak-05 and NARC-09) under control and saline conditions. The outcomes of the current research work are notable, and NPs with such capabilities may be a useful supply of fertilizer in the agricultural industry.

The Effects of Titanium Dioxide Nanoparticles on Osteoblasts Mineralization: A Comparison between 2D and 3D Cell Culture Models.

Although several studies assess the biological effects of micro and titanium dioxide nanoparticles (TiO2 NPs), the literature shows controversial results regarding their effect on bone cell behavior. Studies on the effects of nanoparticles on mammalian cells on two-dimensional (2D) cell cultures display several disadvantages, such as changes in cell morphology, function, and metabolism and fewer cell-cell contacts. This highlights the need to explore the effects of TiO2 NPs in more complex 3D environments, to better mimic the bone microenvironment. This study aims to compare the differentiation and mineralized matrix production of human osteoblasts SAOS-2 in a monolayer or 3D models after exposure to different concentrations of TiO2 NPs. Nanoparticles were characterized, and their internalization and effects on the SAOS-2 monolayer and 3D spheroid cells were evaluated with morphological analysis. The mineralization of human osteoblasts upon exposure to TiO2 NPs was evaluated by alizarin red staining, demonstrating a dose-dependent increase in mineralized matrix in human primary osteoblasts and SAOS-2 both in the monolayer and 3D models. Furthermore, our results reveal that, after high exposure to TiO2 NPs, the dose-dependent increase in the bone mineralized matrix in the 3D cells model is higher than in the 2D culture, showing a promising model to test the effect on bone osteointegration.

Enhanced Structural, Optical Properties and Antibacterial Activity of PEO/CMC Doped TiO2 NPs for Food Packaging Applications.

In this article, the synthesis, optical, and electrical properties of composites consisting of polyethylene oxide (PEO), carboxymethyl cellulose (CMC), and titanium dioxide nanoparticles are examined. Flexible nanocomposite samples comprising PEO, CMC, and TiO2 nanoparticles were produced swiftly via using the cast synthesis method. In addition, XRD and FT-IR analysis were performed in order to analyze the structures of the prepared samples. Our results demonstrate the PEO/CMC blend's effectiveness in interacting with TiO2 nanoparticles. The optical properties of the PEO/CMC and nanocomposite samples, such as the energy band gap, were studied using the UV/Vis optical absorbance. It was found that as TiO2 NP weight fraction increases, the energy gap narrows. Moreover, TiO2 nanoparticles with an average size of 16 nm were formed in spherical and rod shapes, according to a TEM image. The SEM images demonstrate how the distribution of TiO2 NPs increased upon the surfaces of the prepared films. The antibacterial activity in the nanocomposites was shown to be enhanced by the TiO2 NP concentrations. Finally, we proposed that PEO/CMC-0.8 wt. % TiO2 nanocomposites with enhanced optical, electrical, and dielectric properties should be used in electrochemical devices.

Comprehensive analysis revealed that titanium dioxide nanoparticles could strengthen the resistance of apple rootstock B9 to saline-alkali stress.

Apple growth and development can be adversely affected by saline-alkali stress, which has become a significant factor restricting the high yield of the apple industry. In recent years, nanomaterials have become a potential source for plant growth and development. Titanium dioxide nanoparticles (TiO2 NPs) play an important role in multiple plant development processes, including mitigating environmental stress. In this study, one-year-old apple rootstock B9 stem cuttings were used as research objects. Different concentrations of TiO2 NPs were applied to the roots before saline-alkali treatment. Principal component analysis showed that 1gkg-1 TiO2 NPs treatment had the best effect in alleviating the stress for B9. It significantly reduced the damage to B9 under salt-alkali stress, increased the content of photosynthetic pigment, enhanced the performance of Photosystem II, and promoted photosynthesis. At the same time, the content of K+ was increased, and the ion toxicity was alleviated. In addition, TiO2 NPs have also been shown to reduce B9 cell damage and lipid peroxidation, increase antioxidant enzyme activity, and regulate the accumulation of solutes. Overall, this study provides a theoretical basis for TiO2 NPs to mitigate the adverse effects of plants under saline-alkali stress and provides useful insights for managing other plants affected by global salinity and alkalinity.

Environmental exposure and nanotoxicity of titanium dioxide nanoparticles in irrigation water with the flavonoid luteolin.

Different concentrations of titanium oxide nanoparticles (TiO2NPs) have been frequently reported in treated wastewater used for the irrigation of crops. Luteolin is a susceptive anticancer flavonoid in many crops and rare medicinal plants that can be affected by exposure to TiO2NPs. This study investigates the potential transformation of pure luteolin in exposure to TiO2NP-containing water. In an in vitro system, three replicates of 5 mg L-1 of pure luteolin were exposed to TiO2NPs (0, 25, 50, 100 ppm). After 48 h exposure, the samples were extensively analyzed by Raman spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, and dynamic light scattering (DLS). A positive correlation was found between TiO2NPs concentrations and the structural alteration of luteolin content, where over 20% of luteolin structure was allegedly altered in the presence of 100 ppm TiO2NPs. The increase of NPs diameter (∼70 nm) and dominant peaks in Raman spectra revealed that luteolin was adsorbed onto the TiO2NPs surface. Further, the second-order derivative analysis confirmed the transformation of luteolin upon exposure to TiO2NPs. This study provides fundamental insight into agricultural safety measures when exposed to air or water-borne TiO2NPs.

Phytochemical and physiological reactions of feverfew (Tanacetum parthenium (L.) Schultz Bip) to TiO2 nanoparticles

Nanomaterials can be used as elicitors for improving the biosynthesis of secondary metabolites in medicinal plants. The present study was conducted to assay the titanium dioxide-nanoparticles (TiO2-NPs) effects on feverfew (Tanacetum parthenium) as an anti-cancer plant. The study showed that TiO2-NPs application increased the amounts of the main compounds and oxygenated monoterpene in essential oils, thereby causing an improvement in the quantity and quality of the essential oils compared to control. The highest effect was related to 1500 ppm TiO2-NPs concentration. Regarding parthenolide, TiO2-NPs had no positive effect on parthenolide content and the highest content was observed in control. Increasing the concentrations over 1500 ppm resulted in a decrease in chlorophyll content, capitule diameter, flower yield, and harvest index compared to other concentrations and control. Additionally, the results indicated that TiO2-NPs foliar spray reduced flower number, biological yield, fresh weight, and dry weights compared with untreated plants. The increase in quality and content of essential oil and lack of increase in parthenolide content, and reproductive and vegetative characteristics showed that TiO2-NPs mainly affected the content and composition of essential oil. Totally, the application of TiO2-NPs in terms of positive effect on the yield and metabolites (without damaging biological effects) can be recommended and followed up to the concentration of 1000 ppm. Overall, the results indicated that improving the synthesis of valuable medicinal metabolites using TiO2-NPs has promising results depending on the type of species, concentration used and target metabolites.

Phytosynthesis of TiO2 Nanoparticles Using E. crassipes Leaf Extracts, Their Photocatalytic Evaluation and Microbicide Effect

In the present research work, the photocatalytic and microbicidal activities of titanium nanoparticles (TiO2 NPs) were evaluated. TiO2 NPs were obtained through the phytosynthesis process, using Eichhornia crassipes leaf extract. In order to determine whether particle size improves photocatalytic and microbicidal activities, the pH of the photosynthesized was modified to 12, 7, and 4. The TiO2 NPs modified were characterized by UV-Vis spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and high-resolution transmission electron microscopy (HR-TEM) to reveal the crystalline and morphological nature of the phytosynthesized TiO2 NPs. UV-Vis analysis revealed that the wavelength for the TiO2 NPs was 327 nm, while FT-IR confirmed the presence of TiO2 NPs at peaks located between 536 and 532 cm-1. Finally, HR-TEM analysis showed that all nanoparticles had a TiO2 composition and a particle size ranging from 25 to 35 nm. For the photocatalytic and microbicidal tests, three concentrations of nanoparticles were used (100, 50, and 10 mg/L), and the results showed that TiO2 nanoparticles at a concentration of 10 mg·L-1 demonstrated excellent photocatalytic activity in photodegrading phenol [10 mg·L-1] up to 98.7%, while their microbicidal activity was more effective in contact with S. aureus than with E. coli, using a TiO2 NPs concentration of 100 mg·L-1.

Potential of green synthesized titanium dioxide nanoparticles for enhancing seedling emergence, vigor and tolerance indices and DPPH free radical scavenging in two varieties of soybean under salinity stress

BackgroundConsidering titanium dioxide nanoparticles (TiO2 NPs) role in plant growth and especially in plant tolerance against abiotic stress, in the present work, TiO2 NPs were green synthesized using an aqueous solution of Aloe vera leaf extract as a capping agent and titanium tetrachloride as a precursor. These green synthesized TiO2 NPs were characterized using different techniques: UV spectrophotometer, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Results revealed that synthesized TiO2 NPs possess a tetragonal morphology with a size ranging from 10 to 25 nm. Additionally, the present work evaluated the effects of three concentrations of TiO2 NPs (0, 30 and 50 ppm) and six NaCl concentrations (0, 25, 50, 100, 150 and 200 mM) and their interactions with respect to germination parameters, vigor indices, oxidative stress and DPPH free radical scavenging of two varieties of soybean (Glycine max L. var. 22 and 35).ResultsResults demonstrated that all germination traits and vigor indices were negatively affected under all salinity levels. Also, the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were significantly increased by increasing the NaCl concentrations in two soybean varieties. Most interestingly, TiO2 NPs (30 ppm) mediated positive effects on germination parameters, reducing H2O2 and MDA contents by enhancing antioxidant (decreasing IC50) whereas 50 ppm showed an intermediate response under both control and saline soil conditions.ConclusionOur findings demonstrate the growth enhancement effects of TiO2 NPs application as well as its ameliorative potential in dealing with salinity.

Nanopriming Technology for Boosting Germination of Capsicum annum using Mycosynthesized TiO2 Nanoparticles

The aim of this research paper is to investigate the impact of titanium oxide nanoparticles (TiO2 NPs) on germination of Capsicum annum (Pusa Sadabahar). TiO2 Nps were prepared using Fusarium oxysporum extract and then characterized through UV- visible spectroscopy, FTIR, XRD and SEM which confirms that nanoparticles were elongated spherical with 15nm diameter. Various concentration (100-500µg/ml) of TiO2 NPs were used to study different aspects of nanoparticles on Capsicum annum. The result emphasizes the positive effects of TiO2 nanoparticles up to the concentration of 400µg/ml on germination percentage and other morpho-physical parameters such as radical length, plumule length, fresh and dry weight, total seedling length as compared with non-treated plants. Overall we found better results of using biologically synthesized NPs in chilli plants, while the significant decrease in outcome was also observed at higher concentration.

Antimicrobial and anti-biofilm activity of titanium dioxide nanoparticles alone and in combination with erythromycin against methicillin-resistant Staphylococcus aureus

Background: S. aureus is a major pathogen and the predominant bacteria that causes hospital-acquired infections. TiO2NPs have unique characteristics and expanding use for different applications in nanomedicine and have attracted enormous interest in the various rising nanoproducts. Objective: To evaluate the anti-bacterial and anti-biofilm activities of TiO2NPs alone and in combination with the macrolide class of drugs (Erythromycin) against S. aureus isolated from different clinical specimens. Methods: Kirby-Bauer’s disk diffusion technique was applied for antimicrobial susceptibility testing against S. aureus isolates. The Minimum inhibitory concentrations of TiO2NPs and erythromycin were performed with the broth microdilution method, while biofilm formation was investigated by the Calgary technique. Results: At a total of eighty-five strains of S. aureus clinical isolates from patients who are in hospitals in the medical city of Baghdad, 34 (40%) of S. aureus were sensitive to penicillin class (Methicillin) while 51 (60%) were resistant to methicillin, with statistical significance between both groups (P <0.05). In urine samples, the majority of S. aureus isolates were 21 (24.7%), followed by sputum with 14 (16.5%) samples. Patients infected with S. aureus were significant among age groups of 45–54 years old and patients with Ages between 15 and 35 indicate a lower susceptibility to S. aureus infection.mThe results showed that the prevalence of infection with S. aureus was significantly higher among female patients 30 (35.3%) rather than male patients 21 (24.7%), and the male/female ratio was 0.46/1. Vancomycin and imipenem were the most active antibiotics against MSSA and MRSA, with sensitivity of 85 (100%) and 82 (96.5%) for vancomycin and imipenem, respectively, whereas MRSA and MSSA exhibited marked resistance to ciprofloxacin and azithromycin, with sensitivity of 64 (75.3%) and 38 (44.7%), respectively.mTiO2NPs showed excellent biofilm inhibitory activity against MRSA and MSSA isolates, and results showed that TiO2 NPs alone with ½MIC can inhibit biofilm formation by about 40% of MRSA and about 60% of MSSA. Moreover, the combination of TiO2 NPs with erythromycin inhibits biofilm formation by approximately 80–90% for MRSA and MSSA, respectively.

Biosynthesis of TiO2 nanoparticles by Caricaceae (Papaya) shell extracts for antifungal application

Titanium dioxide nanoparticles (TiO2 NPs) were prepared by Caricaceae (Papaya) Shell extracts. The Nanoparticles were analyzed by UV–Vis spectrums, X-ray diffractions, and energy-dispersive X-rays spectroscopy analyses with a scanning electron microscope. An antifungal study was carried out for TiO2 NP in contradiction of S. sclerotiorums, R. necatrixs and Fusarium classes that verified a sophisticated inhibitions ratio for S. sclerotiorums (60.5%). Germs of pea were individually preserved with numerous concentrations of TiO2 NPs. An experience of TiO2 NPs (20%, 40%, 80% and 100%), as well as mechanisms that instigated momentous alterations in seed germinations, roots interval, shoot lengths, and antioxidant enzymes, were investigated. Associated with controls, the supreme seeds germinations, roots and plant growth were perceived with the treatments of TiO2 NPs. Super-oxide dis-mutase and catalase activities increased because of TiO2 NPs treatments. This advocates that TiO2 Nanoparticles may considerably change antioxidant metabolisms in seed germinations.

Enhanced Cd2+ adsorption and toxicity for microbial biofilms in the presence of TiO2 nanoparticles

Titanium dioxide nanoparticles (TiO2 NPs) easily combine with other pollutants such as heavy metals because of their excellent physiochemical properties. However, how such an interaction may affect the binding behavior of metals onto biofilms remains largely unclear. This study, examined the effects of TiO2 NPs on Cd2+ accumulation and toxicity for natural periphytic biofilms were examined. The adsorption kinetics showed that adding 0.1 and 1 mg/L TiO2–NPs increased the Cd2+ adsorption of biofilms at equilibrium by 23.5% and 35.8%, respectively. However, adding 10 mg/L TiO2 NPs increased the Cd2+ adsorption of biofilms at equilibrium by only 1.9%. The adsorption isotherms indicate that the presence of TiO2 NPs considerably increased the Cd2+ adsorption capacity of the biofilms; however, this effect became less prominent at high TiO2 NP concentrations. The optimum pH for Cd2+ adsorption increased with increasing Cd2+ and TiO2 NP contents. At low concentrations, the coexistence of Cd2+ and TiO2 NPs may facilitate their respective accumulation by stimulating the secretion of extracellular polymeric substances and enhancing the microbial activity of the biofilm. The presence of TiO2 NPs increases the surface binding energy between Cd2+ and functional groups such as carboxyl groups, enhancing the Cd2+ accumulation on the biofilm.

Sediment Bacteria and Phosphorus Fraction Response, Notably to Titanium Dioxide Nanoparticle Exposure.

Titanium dioxide nanoparticle (TiO2 NP) toxicity to the growth of organisms has been gradually clarified; however, its effects on microorganism-mediated phosphorus turnover are poorly understood. To evaluate the influences of TiO2 NPs on phosphorus fractionation and the bacterial community, aquatic microorganisms were exposed to different concentrations of TiO2 NPs with different exposure times (i.e., 0, 10, and 30 days). We observed the adhesion of TiO2 NPs to the cell surfaces of planktonic microbes by using SEM, EDS, and XRD techniques. The addition of TiO2 NPs resulted in a decrease in the total phosphorus of water and an increase in the total phosphorus of sediments. Additionally, elevated TiO2 NPs enhanced the sediment activities of reductases (i.e., dehydrogenase [0.19–2.25 μg/d/g] and catalase [1.06–2.92 μmol/d/g]), and significantly decreased the absolute abundances of phosphorus-cycling-related genes (i.e., gcd [1.78 × 104–9.55 × 105 copies/g], phoD [5.50 × 103–5.49 × 107 copies/g], pstS [4.17 × 102–1.58 × 106 copies/g]), and sediment bacterial diversity. TiO2 NPs could noticeably affect the bacterial community, showing dramatic divergences in relative abundances (e.g., Actinobacteria, Acidobacteria, and Firmicutes), coexistence patterns, and functional redundancies (e.g., translation and transcription). Our results emphasized that the TiO2 NP amount—rather than the exposure time—showed significant effects on phosphorus fractions, enzyme activity, phosphorus-cycling-related gene abundance, and bacterial diversity, whereas the exposure time exhibited a greater influence on the composition and function of the sediment bacterial community than the TiO2 NP amount. Our findings clarify the responses of phosphorus fractions and the bacterial community to TiO2 NP exposure in the water–sediment ecosystem and highlight potential environmental risks of the migration of untreated TiO2 NPs to aquatic ecosystems.

Exogenous Application of Green Titanium Dioxide Nanoparticles (TiO2 NPs) to Improve the Germination, Physiochemical, and Yield Parameters of Wheat Plants under Salinity Stress.

Agriculture is the backbone of every developing country. Among various crops, wheat (Triticum aestivum L.) belongs to the family Poaceae and is the most important staple food crop of various countries. Different biotic (viruses, bacteria and fungi) and abiotic stresses (water logging, drought and salinity) adversely affect the qualitative and quantitative attributes of wheat. Among these stresses, salinity stress is a very important limiting factor affecting the morphological, physiological, biochemical attributes and grain yield of wheat. This research work was carried out to evaluate the influence of phytosynthesized TiO2 NPs on the germination, physiochemical, and yield attributes of wheat varieties in response to salinity. TiO2 NPs were synthesized using TiO2 salt and a Buddleja asiatica plant extract as a reducing and capping agent. Various concentrations of TiO2 nanoparticles (20, 40, 60 and 80 mg/L) and salt solutions (NaCl) (100 and 150 mM) were used. A total of 20 mg/L and 40 mg/L improve germination attributes, osmotic and water potential, carotenoid, total phenolic, and flavonoid content, soluble sugar and proteins, proline and amino acid content, superoxide dismutase activity, and reduce malondialdhehyde (MDA) content at both levels of salinity. These two concentrations also improved the yield attributes of wheat varieties at both salinity levels. The best results were observed at 40 mg/L of TiO2 NPs at both salinity levels. However, the highest concentrations (60 and 80 mg/L) of TiO2 NPs showed negative effects on germination, physiochemical and yield characteristics and causes stress in both wheat varieties under control irrigation conditions and salinity stress. Therefore, in conclusion, the findings of this research are that the foliar application of TiO2 NPs can help to improve tolerance against salinity stress in plants.

Polymethylmethacrylate Denture Base Layering as a New Approach for the Addition of Antifungal Agents.

To introduce a new technique, denture base layering, for the addition of titanium dioxide nanoparticles (TiO2 NPs) to polymethylmethacrylate (PMMA) and to investigate the effects of the layering technique on Candida albicans (C. albicans) adhesion and on surface roughness, hardness, translucency, and flexural strength. In total, 210 heat-polymerized acrylic resin specimens were prepared as discs (15 × 2 mm) for testing C. albicans adhesion (n = 70) and surface roughness, hardness, and translucency (n = 70); and as acrylic plates (65 × 10 × 2.5 mm) for testing flexural strength (n = 70). Specimens were divided into 4 groups: control (n = 30), one-layer (n = 60), double-layer (n = 60), and dotted-layer (n = 60) according to the packing and layering technique. Each group was divided according to the concentration of TiO2 NPs 1% and 2.5% (n = 10). The control group comprised one layer of unmodified resin. The one-layer group comprised one layer of a mixture of PMMA/TiO2 NPs packed conventionally. The double-layer group consisted of two different layers packed in two steps, as follows: unmodified resin first, followed by a continuous thin layer of the PMMA/TiO2 NPs mixture. Similarly, the dotted-layer group consisted of two different layers packed in two steps, as follows: unmodified resin first, followed by a thin layer of the PMMA/TiO2 NPs. However, the second mixture was added in a dotted manner. The direct culture method for C. albicans adhesion before and after ultraviolet light activation, and surface roughness, hardness, translucency, and flexural strength were measured. An analysis of variance and Tukey's post hoc test were used for data analysis (α = 0.05). The addition of TiO2 NPs reduced C. albicans adhesion (p < 0.001). However, no significant difference was found between both concentrations within the same group before and after ultraviolet light activation (p > 0.05), except in the 1% dotted-layer (p = 0.022). Surface roughness and hardness were not affected by the additions of different concentrations of TiO2 NPs (p = 0.905) and (p = 0.059), respectively. Translucency was significantly reduced in all the groups (p < 0.001) except in the 1% dotted-layer (p = 0.332). Flexural strength decreased as the TiO2 NPs concentration increased, with the greatest reduction in strength observed in the one-layer group (p < 0.001). The double and dotted layering techniques were effective in reducing C. albicans adhesion, without affecting surface roughness, hardness, or flexural strength. However, translucency was reduced in all the groups, except the 1% dotted-layer group.

Evaluation of Effects of Titanium Dioxide and Zinc Oxide Nanoparticles on Baker’s Yeast (Saccharomyces cerevisiae) Glutathione Reductase Activities

The glutathione reductase (GR) of baker's yeast (Saccharomyces cerevisiae) was exposed to titanium dioxide nanoparticles (TiO2 NPs) and zinc oxide nanoparticles (ZnO NPs) at concentrations of 0, 25, 50, 100, 250, and 500mg/L (ppm) in vitro. According to the calculations, the effect of 25, 50, 100, 250, and 500mg/L TiO2 NPs on GR enzyme activities resulted in percentage changes of - 3.12; - 0.87; - 2.12; - 2.12, and - 1.50, respectively. Percentage changes in GR enzyme activities with the effect of 25, 50, 100, 250, and 500mg/L ZnO NPs were calculated as - 2.01; + 1.88; + 0.38; - 2.51, and + 0.75, respectively. It can be deduced from this research that the change in concentrations of TiO2 NPs and ZnO NPs has no statistically significant effect on GR enzyme activities in comparison with the control groups (p > 0.05, N = 3).

TiO2 nanoparticle synthesis, characterization and application to shoot regeneration of water hyssop (Bacopa monnieri L. Pennel) in vitro

ABSTRACT Water hyssop (Bacopa monnieri L. Pennel) is a medicinal aquatic herb used to treat diseases in South Asia. Various regeneration protocols have been developed or modified in vitro to ensure the availability of biomass and secondary metabolites of Bacopa. We applied hydrothermally treated titanium dioxide (TiO2) nanoparticles (NPs) (TiO2-NPs) at different concentrations. Three explants, distal portion of half leaf (DPHL), proximal portion of half leaf (PPHL) and full leaf (FL), were used to evaluate response to TiO2. Regeneration from the three explants in vitro was similar except for shoot length. Application of TiO2-NPs exerted significant, but variable, effects on all parameters except percentage of shoot formation, which was 100%. Interactive effects of explant and TiO2-NPs exhibited significant, but variable, effects on fresh weight and percentage of callus formation. All explants produced more shoots using TiO2-NPs compared to control treatments. DPHL explants with application of 8 mg/l TiO2 produced more shoots than controls. Similarly, FL explant treated with 2 mg/l TiO2-NPs produced more shoots/explant than controls. All concentrations of TiO2-NPs produced significantly longer shoots compared to controls. Increased elongation of shoots justifies use of TiO2-NPs for propagation of plants in vitro during acclimatization. Use of TiO2-NPs for rapid elongation of shoots ultimately fosters survival of plants.

A comparative proteomics study of Arabidopsis thaliana responding to the coexistence of BPA and TiO2-NPs at environmentally relevant concentrations

Through the applications of recycling sewage sludge to soils as nutrients, bisphenol A (BPA) and titanium dioxide nanoparticles (TiO2-NPs) are commonly found in the agricultural environment. Previous studies have reported that BPA and nanoparticles are harmful to the environment. However, the combined toxicity of both compounds is not yet understood. This work presented an in-depth proteomic analysis of Arabidopsis thaliana exposed to BPA and TiO2-NPs concurrently at environmentally relevant levels. Seeds were simultaneously treated with varying concentrations of BPA (0, 10, 100, and 1000 µg·kg−1) and TiO2-NPs (0, 1, 10 and 100 mg·kg−1). In treatment of 1000 µg·kg−1 BPA and 100 mg·kg−1 TiO2-NPs, highest seed germination rate (87.97%, p < 0.05) was observed. Shorter primary roots but more branched roots were obtained in treatments of high BPA and NPs concentrations (100, 1000 µg·kg−1 BPA and 10, 100 mg·kg−1 TiO2-NPs) while no significant effects on plant height and biomass were found. In the comparative analysis, both concentration related positive and negative effects were observed, such as regulation of cell proliferation (positive), root hair elongation (positive), cellular response to oxidative stress (negative), and cell wall organization (negative). In response to the stress caused by BPA and TiO2-NPs, some proteins related to plant root development, such as CD48E, DNAJ2 and GL24, were up-regulated explaining the shorter primary root length and more branched roots. Moreover, Arabidopsis may have stimulated its ability of resource transportation and energy metabolism to overcome the stress and maintain or somehow enhance their growth by up-regulating proteins like TBB6, CALM1, RAA2A, G3PP2 and KASC1. Our comparative proteomics analysis also highlighted multiple biological processes that consequently lead to the stability of plant growth and its stress adaptation. The results demonstrated that applying biosolids to soil as a fertilizer may be considered as a sustainable practice.

Effects of Titanium Dioxide Nanoparticles on Cell Growth and Migration of A549 Cells under Simulated Microgravity

With the increasing application of nanomaterials in aerospace technology, the long-term space exposure to nanomaterials especially in the space full of radiation coupled with microgravity condition has aroused great health concerns of the astronauts. However, few studies have been conducted to assess these effects, which are crucial for seeking the possible intervention strategy. Herein, using a random positioning machine (RPM) to simulate microgravity, we investigated the behaviors of cells under simulated microgravity and also evaluated the possible toxicity of titanium dioxide nanoparticles (TiO2 NPs), a multifunctional nanomaterial with potential application in aerospace. Pulmonary epithelial cells A549 were exposed to normal gravity (1 g) and simulated gravity (~10−3 g), respectively. The results showed that simulated microgravity had no significant effect on the viability of A549 cells as compared with normal gravity within 48 h. The effects of TiO2 NPs exposure on cell viability and apoptosis were marginal with only a slightly decrease in cell viability and a subtle increase in apoptosis rate observed at a high concentration of TiO2 NPs (100 μg/mL). However, it was observed that the exposure to simulated microgravity could obviously reduce A549 cell migration compared with normal gravity. The disruption of F-actin network and the deactivation of FAK (Tyr397) might be responsible for the impaired mobility of simulated microgravity-exposed A549 cells. TiO2 NPs exposure inhibited cell migration under two different gravity conditions, but to different degrees, with a milder inhibition under simulated microgravity. Meanwhile, it was found that A549 cells internalized more TiO2 NPs under normal gravity than simulated microgravity, which may account for the lower cytotoxicity and the lighter inhibition of cell migration induced by the same exposure concentration of TiO2 NPs under simulated microgravity at least partially. Our study has provided some tentative information on the effects of TiO2 NPs exposure on cell behaviors under simulated microgravity.

Effect of green synthesized nano-titanium synthesized from Trachyspermum ammi extract on seed germination of Vigna radiate

The current work investigates the conditional influence on Vigna radiate seed germination in vitro and in vivo using the green chemistry approach for the manufacture of titanium dioxide nanoparticles (TiO2 NPs) from seed extract of Trachyspermum ammi (T. ammi). Ultraviolet spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to analyze the TiO2 NPs produced. The crystalline nature of TiO2 NP was revealed by XRD data, and TEM investigation revealed an irregularity in TiO2 NP shape with a size of 17.5 nm. UV absorbance at 315 nm for the TiO2 NPs was observed using Ultraviolet–visible spectrophotometer. The antioxidant potential of the synthesized nanoparticle was discovered to be good. In case of seed germination studies, six concentrations (25, 50 100, 150, 200, and 250 μg mL− 1) of TiO2 NPs were examined along with the control on Vigna radiata seeds. Germination parameters such as seed vigor index (SVI), germination percentage (GP), germination value (GV) root length (RL) and shoot length (SL) of the Vigna radiata seedlings were observed and results revealed that the green synthesized TiO2 NPs were significantly improved. The results indicated that the TiO2 NP affected the plant growth more specifically at lower concentration (50 μg mL−1) of TiO2 NPs. Overall, the findings of this present study stipulated that the green TiO2 NP production can enhance the growth of Vigna radiate under in vitro and in vivo conditions.