Sorption isotherms of metal ions onto an N-(2-sulfoethyl)chitosan-based material from single- and multi-component solutions

The scope of work is to study the mutual influence of metal ions during their sorption by sulfoethylated chitosan. The sorption isotherms of metal ions from single- and multi-component solutions are obtained. The sorption capacity of the sorbent towards Ag(I) and Cu(II) is revealed to be 1.63 and 1.41 mmol/g in single-, and 1.40 and 0.85 mmol/g in five-component solution. By comparing the affinity parameter and capacity of sulfoethylated chitosan towards ions in single- and multi-component solutions, it is concluded that Ag(I) and Cu(II) ions suppress the sorption of cobalt(II), nickel(II), zinc(II), cadmium(II), magnesium(II), calcium(II), strontium(II), barium(II), manganese(II) and lead(II).     

Small RNA F6 Provides Mycobacterium smegmatis Entry into Dormancy

Regulatory small non-coding RNAs play a significant role in bacterial adaptation to changing environmental conditions. Various stresses such as hypoxia and nutrient starvation cause a reduction in the metabolic activity of Mycobacterium smegmatis, leading to entry into dormancy. We investigated the functional role of F6, a small RNA of M. smegmatis, and constructed an F6 deletion strain of M. smegmatis. Using the RNA-seq approach, we demonstrated that gene expression changes that accompany F6 deletion contributed to bacterial resistance against oxidative stress. We also found that F6 directly interacted with 5′-UTR of MSMEG_4640 mRNA encoding RpfE2, a resuscitation-promoting factor, which led to the downregulation of RpfE2 expression. The F6 deletion strain was characterized by the reduced ability to enter into dormancy (non-culturability) in the potassium deficiency model compared to the wild-type strain, indicating that F6 significantly contributes to bacterial adaptation to non-optimal growth conditions.     

Carbenoxolon Is Capable to Regulate the Mitochondrial Permeability Transition Pore Opening in Chronic Alcohol Intoxication

Background: carbenoxolone, which is a derivative of glyceretic acid, is actively used in pharmacology for the treatment of diseases of various etiologies. In addition, we have shown carbenoxolone as an effective inducer of mitochondrial permeability transition pore in rat brain and liver mitochondria. Methods: in the course of this work, comparative studies were carried out on the effect of carbenoxolone on the parameters of mPTP functioning in mitochondria isolated from the liver of control and alcoholic rats. Results: within the framework of this work, it was found that carbenoxolone significantly increased its effect in the liver mitochondria of rats with chronic intoxication. In particular, this was expressed in a reduction in the lag phase, a decrease in the threshold calcium concentration required to open a pore, an acceleration of high-amplitude cyclosporin-sensitive swelling of mitochondria, as well as an increase in the effect of carbenoxolone on the level of mitochondrial membrane-bound proteins. Thus, as a result of the studies carried out, it was shown that carbenoxolone is involved in the development/modulation of alcohol tolerance and dependence in rats.     

Magic Peptide: Unique Properties of the LRR11 Peptide in the Activation of Leukotriene Synthesis in Human Neutrophils

Neutrophil-mediated innate host defense mechanisms include pathogen elimination through bacterial phagocytosis, which activates the 5-lipoxygenase (5-LOX) product synthesis. Here, we studied the effect of synthetic oligodeoxyribonucleotides (ODNs), which mimic the receptor-recognized sites of bacterial (CpG-ODNs) and genomic (G-rich ODNs) DNAs released from the inflammatory area, on the neutrophil functions after cell stimulation with Salmonella typhimurium. A possible mechanism for ODN recognition by Toll-like receptor 9 (TLR9) and RAGE receptor has been proposed. We found for the first time that the combination of the magic peptide LRR11 from the leucine-rich repeat (LRR) of TLR9 with the CpG-ODNs modulates the uptake and signaling from ODNs, in particular, dramatically stimulates 5-LOX pathway. Using thickness shear mode acoustic method, we confirmed the specific binding of CpG-ODNs, but not G-rich ODN, to LRR11. The RAGE receptor has been shown to play an important role in promoting ODN uptake. Thus, FPS-ZM1, a high-affinity RAGE inhibitor, suppresses the synthesis of 5-LOX products and reduces the uptake of ODNs by neutrophils; the inhibitor effect being abolished by the addition of LRR11. The results obtained revealed that the studied peptide-ODN complexes possess high biological activity and can be promising for the development of effective vaccine adjuvants and antimicrobial therapeutics.     

Structural Features and Transport Properties of La(Sr)Fe1-xNixO3-δ– Ce0.9Gd0.1O2-δ Nanocomposites—Advanced Materials for IT SOFC Cathodes

Mixed ionic?electronic conducting nanocomposites comprising complex oxides - perovskite (lanthanum-strontium nickelate-ferrite [LSFN]) and gadolinium-doped ceria (GDC) have been prepared via ultrasonic dispersion of nanocrystalline powders of LSFN_x and GDC in organic solvent with addition of surfactant, followed by drying and sintering up to 1300°C. Their structural and surface properties have been studied by x-ray diffraction, ultraviolet–visible (UV-vis) electron spectroscopy, transmission electron microscopy with elemental analysis, and x-ray photoelectron spectroscopy. Results of impedance spectroscopy, oxygen isotope exchange, O₂ temperature-programmed desorption, weight, and conductivity relaxation experiments have revealed a strong positive effect of perovskite?fluorite nanodomain interfaces in composite on the oxygen mobility and reactivity. Testing in wet H₂/air feeds for a button-size cell with functionally graded LSFN_0.4–GDC cathode layer supported on a thin YSZ layer covering Ni/YSZ cermet has demonstrated high and stable performance, promising for the practical application in the intermediate temperature range.     

Novel Biocompatible Magnetoelectric MnFe2O4 Core@BCZT Shell Nano–Hetero-Structures with Efficient Catalytic Performance

Magnetoelectric (ME) small-scale robotic devices attract great interest from the scientific community due to their unique properties for biomedical applications. Here, novel ME nano hetero-structures based on the biocompatible magnetostrictive MnFe₂O₄ (MFO) and ferroelectric Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ (BCZT) are developed solely via the hydrothermal method for the first time. An increase in the temperature and duration of the hydrothermal synthesis results in increasing the size, improving the purity, and inducing morphology changes of MFO nanoparticles (NPs). A successful formation of a thin epitaxial BCZT-shell with a 2–5 nm thickness is confirmed on the MFO NPs (77 ± 14 nm) preliminarily treated with oleic acid (OA) or polyvinylpyrrolidone (PVP), whereas no shell is revealed on the surface of pristine MFO NPs. High magnetization is revealed for the developed ME NPs based on PVP- and OA-functionalized MFO NPs (18.68 ± 0.13 and 20.74 ± 0.22 emu g⁻¹, respectively). Moreover, ME NPs demonstrate 95% degradation of a model pollutant Rhodamine B within 2.5 h under an external AC magnetic field (150 mT, 100 Hz). Thus, the developed biocompatible core–shell ME NPs of MFO and BCZT can be considered as a promising tool for non-invasive biomedical applications, environmental remediation, and hydrogen generation for renewable energy sources.     

Carbon Segregation in CoCrFeMnNi High-Entropy Alloy Driven by High-Pressure Torsion at Room and Cryogenic Temperatures

Herein, a CoCrFeMnNi high-entropy alloy with reduced Cr content and with the addition of 2 at% C interstitial is processed via high-pressure torsion (HPT) under 6.5 GPa by three turns at room and cryogenic temperatures. The microstructure is investigated by transmission electron microscopy (TEM) and atom probe tomography (APT). The results indicate that C atoms segregate at the boundaries of the nanograins in the sample processed at room temperature, while the sample processed at cryogenic temperature does not show any notable segregations of carbon.     

Magnetically Controlled Carbonate Nanocomposite with Ciprofloxacin for Biofilm Eradication

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.