Alkylresorcinols as New Modulators of the Metabolic Activity of the Gut Microbiota.

Alkylresorcinols (ARs) are polyphenolic compounds with a wide spectrum of biological activities and are potentially involved in the regulation of host metabolism. The present study aims to establish whether ARs can be produced by the human gut microbiota and to evaluate alterations in content in stool samples as well as metabolic activity of the gut microbiota of C57BL, db/db, and LDLR (-/-) mice according to diet specifications and olivetol (5-n-pentylresorcinol) supplementation to estimate the regulatory potential of ARs. Gas chromatography with mass spectrometric detection was used to quantitatively analyse AR levels in mouse stool samples; faecal microbiota transplantation (FMT) from human donors to germ-free mice was performed to determine whether the intestinal microbiota could produce AR molecules; metagenome sequencing analysis of the mouse gut microbiota followed by reconstruction of its metabolic activity was performed to investigate olivetol's regulatory potential. A significant increase in the amounts of individual members of AR homologues in stool samples was revealed 14 days after FMT. Supplementation of 5-n-Pentylresorcinol to a regular diet influences the amounts of several ARs in the stool of C57BL/6 and LDLR (-/-) but not db/db mice, and caused a significant change in the predicted metabolic activity of the intestinal microbiota of C57BL/6 and LDLR (-/-) but not db/db mice. For the first time, we have shown that several ARs can be produced by the intestinal microbiota. Taking into account the dependence of AR levels in the gut on olivetol supplementation and microbiota metabolic activity, AR can be assumed to be potential quorum-sensing molecules, which also influence gut microbiota composition and host metabolism.

Synthesis, Characterization and Biodistribution of GdF3:Tb3+@RB Nanocomposites.

Herein we report the development of a nanocomposite for X-ray-induced photodynamic therapy (X-PDT) and computed tomography (CT) based on PEG-capped GdF3:Tb3+ scintillating nanoparticles conjugated with Rose Bengal photosensitizer via electrostatic interactions. Scintillating GdF3:Tb3+ nanoparticles were synthesized by a facile and cost-effective wet chemical precipitation method. All synthesized nanoparticles had an elongated "spindle-like" clustered morphology with an orthorhombic structure. The structure, particle size, and morphology were determined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analysis. The presence of a polyethylene glycol (PEG) coating and Rose Bengal conjugates was proved by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and ultraviolet-visible (UV-vis) analysis. Upon X-ray irradiation of the colloidal PEG-capped GdF3:Tb3+-Rose Bengal nanocomposite solution, an efficient fluorescent resonant energy transfer between scintillating nanoparticles and Rose Bengal was detected. The biodistribution of the synthesized nanoparticles in mice after intravenous administration was studied by in vivo CT imaging.

Nanomaterials for Deep Tumor Treatment.

According to statistics, cancer is the second leading cause of death in the world. Thus, it is important to solve this medical and social problem by developing new effective methods for cancer treatment. An alternative to more well-known approaches, such as radiotherapy and chemotherapy, is photodynamic therapy (PDT), which is limited to the shallow tissue penetration (< 1 cm) of visible light. Since the PDT process can be initiated in deep tissues by X-ray irradiation (X-ray induced PDT, or XPDT), it has a great potential to treat tumors in internal organs. The article discusses the principles of therapies. The main focus is on various nanoparticles used with or without photosensitizers, which allow the conversion of X-ray irradiation into UV-visible light. Much attention is given to the synthesis of nanoparticles and analysis of their characteristics, such as size and spectral features. The results of in vitro and in vivo experiments are also discussed.

Comparison of Heavy Metal Content in Artemisia austriaca in Various Impact Zones.

A study on Artemisia austriaca of two anthropogenically heavy metal-polluted impact zones of the Rostov region, namely Lake Atamanskoye and Novocherkasskaya Power Station, was conducted. The influence of soil pollution on the Pb, Zn, and Cu accumulation in various organs of A. austriaca, which is widespread in the studied territories, was established. An extremely high level of Zn content (3051 mg/kg) was observed in the soils of the impact zone of Lake Atamanskoe, as well as an excess over the maximum permissible level for Pb and Cu (32 and 132 mg/kg accordingly). The distribution coefficient (DC) of heavy metal translocation showed the highest mobility of Zn (DC ≥ 1 in 9 out of 11 sites) and the smallest of Pb (DC ≥ 1 in 4 out of 11 sites) in plants of the Novocherkasskaya Power Station impact zone. The zone of increased pollution around Lake Atamanskoye was 1.5 km, which was much smaller than the Novocherkasskaya Power Station zone of high pollution (5 km). However, vehicle emissions accumulated in the soil over the past decades had a greater effect on the Pb translocation than atmospheric emissions of the enterprise.