Due to their chemical, mechanical, and optical properties, 2D ultrathin nanomaterials have significant potential in biomedicine. However, the cytotoxicity of such materials, including their mutual increase or decrease, is still not well understood. We studied the effects that graphene oxide (GO) nanolayers (with dimensions 0.1–3 μm and average individual flake thickness less than 1 nm) and ZrS3 nanoribbons (length more than 10 μm, width 0.4–3 μm, and thickness 50–120 nm) have on the viability, cell cycle, and cell death of HCT116 colon carcinoma cells. We found that ZrS3 exhibited strong cytotoxicity by causing apoptotic cell death, which was in contrast to GO. When adding GO to ZrS3, ZrS3 was significantly less toxic, which may be because GO inhibits the effects of cytotoxic hydrogen sulfide produced by ZrS3. Thus, using zirconium trisulfide nanoribbons as an example, we have demonstrated the ability of graphene oxide to reduce the cytotoxicity of another nanomaterial, which may be of practical importance in biomedicine, including the development of biocompatible nanocoatings for scaffolds, theranostic nanostructures, and others.

Due to the growing population of Earth, the problem of providing food comes to the fore. Therefore, the search for new, economically available sources of trace elements for crop production is relevant. One of these potential sources is blast-furnace sludge: highly dispersed metallurgical waste, the industrial processing of which is difficult due to its high zinc content. We studied the effect of blast-furnace sludge on rapeseed plants in laboratory, greenhouse, and field experiments and also assessed the accumulation of sludge components in plant organs. The studied sludge sample consisted of micron and submicron particles containing compounds of iron, silicon, aluminum, zinc, calcium, and sulfur. Used concentrations: laboratory—0.01, 0.1, 1%, 10, and 100 g L−1; greenhouse—0.01, 0.1, 1, 10, and 100 g kg−1; field—0.5, 2, and 4 t ha−1. During a laboratory experiment, a decrease in the germination of rapeseed seeds exposed to 0.01, 0.1, 10, and 100 g L−1 waste was observed, but 1 g L−1 promoted the increase of this indicator by 7% regarding control (0 g L−1). While inhibiting seed germination, the sludge had a beneficial effect on the vegetative performance of plants. Reverse effects were noted in the greenhouse experiment as an increase in seed germination (introduction of 1 g kg−1 of sludge to the substrate caused maximum stimulation) and a decrease in rapeseed morphometric parameters were observed. However, at a concentration of 10 g kg−1, the root mass increased by 43% and the stem mass by 63%. In the same group, the highest content of chlorophylls was noted. The number of pods in all experimental groups of plants was less than in control (0 g kg−1) plants, but at the same time, in the variants of 0.01 and 1 g kg−1, the weight of seeds was noticeably increased, by 15.6 and 50%, respectively. Under the conditions of the field experiment, the sludge had a positive effect on the indicators of biological and economic productivity. Thus, exposure to 0.5 and 2 t ha−1 of sludge significantly increased the dry matter and leaf area. The highest values of photosynthetic capacity were recorded at a dose of 2 t ha−1. The maximum increase in yield was ensured by the introduction of sludge at a concentration of 0.5 and 2 t ha−1. The sludge dose of 4 t ha−1, which was also used, either had no effect or suppressed the development of the analyzed traits. The study of the accumulation of zinc and iron in the organs of plants showed the absence of a pronounced dose-dependent accumulation of zinc in the organs of rapeseed, while for iron, an increase in the content of the element in the organs of plants associated with an increase in the concentration of sludge in the soil was recorded. Our results demonstrate the promise of further research and development of methods for the agricultural use of highly dispersed sludge from wet gas cleaning of blast furnace production.

The main purpose of the work was to determine the prospects for the use of silver nanoparticles in woody plants tissue culture and to identify possible limitations. The paper presents the results of experiments on the use of silver nanoparticles (AgNPs) to increase the efficiency of in vitro tissue culture of woody plant cultures using the example of gray poplar (Populus × canescens Aiton. Sm.) at various stages of microclonal reproduction. It has been shown that sequential treatment with 7.5 g/L NaOCl for 30 min and 0.3 g/L AgNPs for 5 min allows obtaining 100% phytopathogen-free explants, increasing their viability. Modification of the nutrient medium with AgNPs at concentrations of 1.5…3 μg/L during multiplication and rooting reduces the phytopathogen infestation, and also stimulates the formation of the root system and accelerates the growth of the vegetative part of the shoots. In addition, the combination of photosynthetic and enzymatic activity suggests a rather high potential for stress resistance of experimental microclones in comparison with control ones.

Nanotechnology has a great potential for application in applied biotechnology. Here we demonstrate the effectiveness of synthesized by direct reaction ZrS3 and TiS3 nanoribbons as sterilizing agents, growth stimulators and activators of rhizogenesis of micro-sprouts of tree crops during clonal micropropagation. At the initiation stage at 6 and 15 μg/L ZrS3 and 3, 6 and 15 μg/L TiS3, complete sterility of shoots of brittle willow, red oak and Scots pine was noted. The maximum survival rate and seedling height at this stage was in the groups of 1.5 μg/L ZrS3 and 3 μg/L TiS3. An increase in the concentration of nanomaterials to 15 μg/L significantly reduced the viability of plants. At the proliferation stage the concentration of nanomaterials 1.5 and 3 μg/L increased the survival rate of regenerants, and at 3 μg/L with the phytohormones (benzylaminopurine, indoleacetic acid, gibberelic acid) the number of additional shoots increased. At the rooting stage ZrS3 and TiS3 at doses of 1.5 and 3 μg/L with auxin activated rhizogenesis, significantly increasing the number of seedlings with roots in comparison with the variants where only auxin were used. This effects can be associated both with the direct action of nanoribbons and with the release of hydrogen sulfide as a result of aqueous hydrolysis of nanoribbons, since H2S plays an important role in the regulation of plant physiological processes.

In this work, we present an analysis of the antibacterial activity of TiS3 nanostructures in water and 0.9% NaCl solution suspensions. TiS3 nanoribbons 1–10 µm long, 100–300 nm wide, and less than 100 nm thick were produced by the direct reaction of pure titanium powder with elemental sulphur in a quartz tube sealed under vacuum. For the toxicity test of a bioluminescent strain of E. coli we used concentrations from 1 to 0.0001 g L−1 and also studied fresh suspensions and suspensions left for 24 h. The strongest toxic effect was observed in freshly prepared water solutions where the luminescence of bacteria decreased by more than 75%. When saline solution was substituted for water or when the solutions were stored for 24 h it resulted in a considerable decrease in the TiS3 antibacterial effect. The toxicity of TiS3 in water exceeded the toxicity of the reference TiO2 nanoparticles, though when saline solution was used instead of water the opposite results were observed. In addition, we did not find a relationship between the antibacterial activity of water suspensions of nanoribbons and the stability of their colloidal systems, which indicates an insignificant contribution to the toxicity of aggregation processes. In 0.9% NaCl solution suspensions, toxicity increased in proportion to the increase in the zeta potential. We suppose that the noted specificity of toxicity is associated with the emission of hydrogen sulphide molecules from the surface of nanoribbons, which, depending on the concentration, can either decrease or increase oxidative stress, which is considered the key mechanism of nanomaterial cytotoxicity. However, the exact underlying mechanisms need further investigation. Thus, we have shown an important role of the dispersion medium and the period of storage in the antibacterial activity of TiS3 nanoribbons. Our results could be used in nanotoxicological studies of other two-dimensional nanomaterials, and for the development of novel antibacterial substances and other biomedical applications of this two-dimensional material.