Effect of selenium nanoparticles on biological and morphofunctional parameters of barley seeds (Hordéum vulgáre L.).

The purpose of this work was to study the effect of selenium nanoparticles (Se NPs) on the biological and morphofunctional parameters of barley seeds (Hordéum vulgáre L.) We used seeds of Hordéum vulgáre L. with reduced morphofunctional characteristics. For the experiment, Se NPs were synthesized and stabilized with didecyldimethylammonium chloride. It was found that Se NPs have a spherical shape and a diameter of about 50 nm. According to dynamic light scattering data, the average hydrodynamic radius of the particles was 28 ± 8 nm. It is observed that the nanoparticles have a positive ζ-potential (+ 27.3 mV). For the experiment, we treated Hordéum vulgáre L. seeds with Se NPs (1, 5, 10 and 20 mg/L). The experiment showed that treatment of Hordéum vulgáre L. seeds with Se NPs has the best effect on the length of roots and sprout at concentration of 5 mg/L and on the number and thickness of roots at 10 mg/L. Germinability and germination energy of Hordéum vulgáre L. seeds were higher in group treated with 5 mg/L Se NPs. Analysis of macrophotographs of samples, histological sections of roots and 3D visualization of seeds by microcomputing tomography confirmed the best effect at 5 mg/L Se NPs. Moreover, no local destructions were detected at concentrations > 5 mg/L, which is most likely due to the inhibition of regulatory and catalytic processes in the germinating seeds. the treatment of Hordéum vulgáre L. seeds with > 5 mg/L Se NPs caused significant stress, coupled with intensive formation of reactive oxygen species, leading to a reorientation of root system growth towards thickening. Based on the results obtained, it was concluded that Se NPs at concentrations > 5 mg/L had a toxic effect. The treatment of barley seeds with 5% Se NPs showed maximum efficiency in the experiment, which allows us to further consider Se NPs as a stimulator for the growth and development of crop seeds under stress and reduced morphofunctional characteristics.

Migration of microplastics from plastic packaging into foods and its potential threats on human health.

Microplastics from food packaging material have risen in number and dispersion in the aquatic system, the terrestrial environment, and the atmosphere in recent decades. Microplastics are of particular concern due to their long-term durability in the environment, their great potential for releasing plastic monomers and additives/chemicals, and their vector-capacity for adsorbing or collecting other pollutants. Consumption of foods containing migrating monomers can lead to accumulation in the body and the build-up of monomers in the body can trigger cancer. The book chapter focuses the commercial plastic food packaging materials and describes their release mechanisms of microplastics from packaging into foods. To prevent the potential risk of microplastics migrated into food products, the factors influencing microplastic to the food products, e.g., high temperatures, ultraviolet and bacteria, have been discussed. Additionally, as many evidences shows that the microplastic components are toxic and carcinogenic, the potential threats and negative effects on human health have also been highlighted. Moreover, future trends is summarized to reduce the microplastic migration by enhancing public awareness as well as improving waste management.

Surface-Oxidized Polymer-Stabilized Silver Nanoparticles as a Covering Component of Suture Materials.

In this work, we obtained silver nanoparticles stabilized with polyvinylpyrrolidone, ranging in size from 70 to 110 nm, which exhibits good crystallinity and anisotropic structure. For the first time, we studied the influence of the molar ratio of silver between silver and peroxide on the oxidation process of the nanoparticles and determined the regularities of this process by analyzing changes in absorption spectra. Our results showed that at molar ratios of Ag:H2O2 = 1:1 and 1:5, dependences of changes in the intensity, position and half-width of the absorption band of the plasmon resonance are rectilinear. In vivo studies of silver nanoparticles have shown that silver nanoparticles belong to the toxicity class III (moderately hazardous substance) and to the third group according to the degree of accumulation. We established that silver nanoparticles and oxidized silver nanoparticles form a uniform layer on the surface of the suture material. We found that the use of the suture material with silver nanoparticles and oxidized silver nanoparticles does not cause allergic reactions in the organisms of laboratory animals.