Comparative Analysis of the Cytotoxic Effect of a Complex of Selenium Nanoparticles Doped with Sorafenib, "Naked" Selenium Nanoparticles, and Sorafenib on Human Hepatocyte Carcinoma HepG2 Cells.

Despite the use of sorafenib as one of the most effective drugs for the treatment of liver cancer, its significant limitations remain-poor solubility, the need to use high doses with the ensuing complications on healthy tissues and organs, and the formation of cell resistance to the drug. At the same time, there is more and more convincing evidence of the anticancer effect of selenium-containing compounds and nanoparticles. The aim of this work was to develop a selenium-sorafenib nanocomplex and study the molecular mechanisms of its anticancer effect on human hepatocyte carcinoma cells, where nanoselenium is not only a sorafenib transporter, but also an active compound. We have created a selenium-sorafenib nanocomplex based on selenium nanoparticles with size 100 nm. Using vitality tests, fluorescence microscopy, and PCR analysis, it was possible to show that selenium nanoparticles, both by themselves and doped with sorafenib, have a pronounced pro-apoptotic effect on HepG2 cells with an efficiency many times greater than that of sorafenib (So). "Naked" selenium nanoparticles (SeNPs) and the selenium-sorafenib nanocomplex (SeSo), already after 24 h of exposure, lead to the induction of the early stages of apoptosis with the transition to the later stages with an increase in the incubation time up to 48 h. At the same time, sorafenib, at the studied concentrations, began to exert a proapoptotic effect only after 48 h. Under the action of SeNPs and SeSo, both classical pathways of apoptosis induction and ER-stress-dependent pathways involving Ca2+ ions are activated. Thus, sorafenib did not cause the generation of Ca2+ signals by HepG2 cells, while SeNPs and SeSo led to the activation of the Ca2+ signaling system of cells. At the same time, the selenium-sorafenib nanocomplex turned out to be more effective in activating the Ca2+ signaling system of cells, inducing apoptosis and ER stress by an average of 20-25% compared to "naked" selenium nanoparticles. Our data on the mechanisms of action and the created nanocomplex are promising as a platform for the creation of highly selective and effective drugs with targeted delivery to tumors.

A Polytetrafluoroethylene (PTFE) and Nano-Al2O3 Based Composite Coating with a Bacteriostatic Effect against E. coli and Low Cytotoxicity.

The problem of bacterial contamination through surfaces is important for the food industry. In this regard, there is a growing interest in new coatings based on nanoparticles that can provide a long-term antibacterial effect. Aluminum oxide nanoparticles are a good candidate for such coatings due to their availability and good biocompatibility. In this study, a coating containing aluminum oxide nanoparticles was produced using polytetrafluoroethylene as a polymer matrix-a polymer that exhibits excellent mechanical and physicochemical properties and it is not toxic. The obtained coatings based on "liquid Teflon" containing various concentrations of nanoparticles (0.001-0.1 wt%) prevented the bacterial growth, and they did not exhibit a cytotoxicity on animal cells in vitro. Such coatings are designed not only to provide an antibacterial surface effect, but also to eliminate micro damages on surfaces that inevitably occur in the process of food production.

The Effect of Gold Nanoparticle Concentration and Laser Fluence on the Laser-Induced Water Decomposition.

This Article covers the influence of the concentration of gold nanoparticles on laser-induced water decomposition. It was established that addition of gold nanoparticles intensifies laser-induced water decomposition by almost 2 orders of magnitude. The water decomposition rate was shown to be maximal at a nanoparticle concentration around 1010 NP/mL, whereas a decrease or increase of nanoparticle concentration leads to a decrease of water decomposition rate. It was demonstrated that, if the concentration of nanoparticles in water-based colloid was less than 1010 NP/mL, laser irradiation of the colloid caused formation of molecular hydrogen, hydrogen peroxide, and molecular oxygen. If the concentration of nanoparticles exceeded 1011 NP/mL, only two products, molecular hydrogen and hydrogen peroxide, were formed. Correlations between the water decomposition rate and the main optical and acoustic parameters of optical breakdown-generated plasma were investigated. Variants of laser-induced decomposition of colloidal solutions of nanoparticles based on organic solvents (ethanol, propanol-2, butanol-2, diethyl ether) were also analyzed.