An impedimetric aptasensor for ochratoxin A (OTA) detection has been developed on the base of a gold electrode covered with a new modifier consisting of electropolymerized Neutral Red and a mixture of Au nanoparticles suspended in the dendrimeric polymer Botlorn H30^®. Thiolated aptamer specific to OTA was covalently attached to Au nanoparticles via Au-S bonding. The interaction of the aptamer with OTA induced the conformational switch of the aptamer from linear to guanine quadruplex form followed by consolidation of the surface layer and an increase of the charge transfer resistance. The aptasensor makes it possible to detect from 0.1 to 100 nM of OTA (limit of detection: 0.02 nM) in the presence of at least 50 fold excess of ochratoxin B. The applicability of the aptasensor for real sample assay was confirmed by testing spiked beer samples. The recovery of 2 nM OTA was found to be 70% for light beer and 78% for dark beer.

A series of cobalt (Co) and its oxides based nanoparticles were synthesized by using hyperbranched polyester polyol Boltorn H20 as a platform and sodium borohydride as a reducing agent. UV, FT-IR, XRD, NTA, and TEM methods were employed to obtain physicochemical characteristics of the products. The average diameter of Co nanoparticles was approximately8.2±3.4 nm. Their magnetic properties, including hysteresis loop, field-cooled, and zero field-cooled curves were investigated. The nanoparticles exhibit superparamagnetism at room temperature, accompanied by magnetic hysteresis below the blocking temperature.

Cell therapy is at the forefront of biomedicine in oncology and regenerative medicine. However, there are still significant challenges to their wider clinical application such as limited efficacy, side effects, and logistical difficulties. One of the potential approaches that could overcome these problems is based on extracellular vesicles (EVs) as a cell-free therapy modality. One of the major obstacles in the translation of EVs into practice is their low yield of production, which is insufficient to achieve therapeutic amounts. Here, we evaluated two primary approaches of artificial vesicle induction in primary T cells and the SupT1 cell line—cytochalasin B as a chemical inducer and ultrasonication as a physical inducer. We found that both methods are capable of producing artificial vesicles, but cytochalasin B induction leads to vesicle yield compared to natural secretion, while ultrasonication leads to a three-fold increase in particle yield. Cytochalasin B induces the formation of vesicles full of cytoplasmic compartments without nuclear fraction, while ultrasonication induces the formation of particles rich in membranes and membrane-related components such as CD3 or HLAII proteins. The most effective approach for T-cell induction in terms of the number of vesicles seems to be the combination of anti-CD3/CD28 antibody activation with ultrasonication, which leads to a seven-fold yield increase in particles with a high content of functionally important proteins (CD3, granzyme B, and HLA II).

The third generation hyperbranched polyesterpolyol has been modified with maleic anhydride at various ratios of the polyol to the modifying agent, from 1: 6 to 1: 18. The prepared modified polyols...

The interaction of Co(NO₃)₂ and Cu(NO₃)₂ with hyperbranched polyester containing 7 terminal benzoyl thiocarbamate groups has been studied by IR-Fourier and electron absorption spectroscopy. А new polynuclear complexes of Co(II) and Cu(II) with poly(benzoyl thiocarbamate)-modified hyperbranched polyester have been synthesized. It has been found that the oxygen and sulfur atoms of the peripheral benzoyl thiocarbamate fragments of the macroligand are involved in coordination with metal ions, the metal to ligand ratio being 7 : 1.

Hyperbranched polyester polycarboxylic acids of the second and third generations for use as high-efficiency complexing agents are synthesized. On the basis of these compounds, new metal-polymer complexes of cobalt(II) and copper(II) are prepared for the first time. As evidenced by IR and ERR studies, the central atom in these metal polycarboxylates occurs in the axially symmetric system MO₆. The thermal stability of polymer copper complexes is improved with increases in the content of metal ions, the degree of functionalization, and the generation number of the polyacid platform.