The use of targeted drug delivery systems, including those based on selective absorption by certain receptors on the surface of the target cell, can lead to a decrease in the minimum effective dose and the accompanying toxicity of the drug, as well as an increase in therapeutic efficacy. A fullerene C₆₀ conjugate (FA-PVP-C₆₀) with polyvinylpyrrolidone (PVP) as a biocompatible spacer and folic acid (FA) as a targeting ligand for tumor cells with increased expression of folate receptors (FR) was obtained. Using ¹³C NMR spectroscopy, FT-IR, UV-Vis spectrometry, fluorometry and thermal analysis, the formation of the conjugate was confirmed and the nature of the binding of its components was established. The average particle sizes of the conjugate in aqueous solutions and cell culture medium were determined using dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). The FA-PVP-C₆₀ showed antiradical activity against ^•DPPH, ^•OH and O₂^•−, but at the same time, it was shown to generate ¹O₂. It was found that the conjugate in the studied concentration range (up to 200 μg/mL) is non-toxic in vitro and does not affect the cell cycle. To confirm the ability of the conjugate to selectively accumulate through folate-mediated endocytosis, its uptake into cells was analyzed by flow cytometry and confocal microscopy. It was shown that the conjugate is less absorbed by A549 cells with low FR expression than by HeLa, which has a high level of expression of this receptor.

Viral infections and many other dangerous diseases are accompanied by the development of oxidative stress, which is a consequence of an increase in the level of the reactive oxygen species (ROS). In this regard, the search for effective antioxidants remains highly relevant. We tested fullerenol C₆₀(OH)₃₆ in the context of the connection between its self-assembly in aqueous solutions and cell culture media, antiradical activity, UV cytoprotective action, and antiviral activity against international reference strains of influenza virus A(H1N1)pdm09, A(H3N2), and B subtypes in vitro on the MDCK cell line. Various characterization techniques, including Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, NMR and ESR spectrometry, MALDI-TOF mass spectrometry, thermal analysis (TGA and DSC), dynamic light-scattering (DLS), and ζ-potential measurements, were used to confirm the production of fullerenol and study its self-assembly in aqueous solutions and cell culture media. Fullerenol C₆₀(OH)₃₆ demonstrated the ability to scavenge ^•DPPH, ^•OH, O₂^•− radicals and ¹O₂ and was non-toxic in the range of the studied concentrations (up to 200 μg/mL) when incubated with MDCK cells for 24 h. In addition, fullerenol exhibited a cytoprotective effect under UV irradiation (EC₅₀ = 29.7 ± 1.0 μM) and showed moderate activity against human influenza viruses of subtypes A(H1N1)pdm09 (SI = 9.9 ± 4.6) and A(H3N2) (SI = 12.5 ± 1.3) when determined by the hemagglutination assay (HA-test) and the MTT assay. At the same time, C₆₀(OH)₃₆ was ineffective in vitro against the actual strain of influenza B virus (Victoria lineage). The high bioavailability of fullerenol in combination with its cytoprotective effect, as well as its antiradical and antiviral activity combined with a relatively low toxicity, allows to consider it a promising compound for biomedical applications.

Background. One of the components of the metabolome that performs multifaceted functions in homeostasis is blood albumin. The albumin molecule has a pronounced hydrophilicity, due to which it plays an important role in maintaining oncotic blood pressure. Thus, the expansion of knowledge about the interrelationships of traditional biochemical information about the concentration of albumin and the biophysical properties of its derivatives complements the idea of the pharmacological effect of albumin transfusions. THE AIM: to study of the biophysical properties of albumin in patients with chronic kidney disease on programmed hemodialysis.Patients and Methods. The study included 29 patients with chronic renal failure treated with programmed bicarbonate hemodialysis for an average of 110 months. To assess the condition of patients, a complex of laboratory studies was used, including hematological examination on Beckman Coulter analyzers; clinical assessment of nutritional status based on data from the analysis of medical histories; assessment of colloidal osmotic blood pressure by calculation, as well as by direct measurement on a BMT 923 oncometer; measurement of particle size in blood plasma by dynamic light scattering on a Photocor Compact spectrometer- Z. Statistical analysis of the material was performed using the Statistica for Windows v.6.0 software package. The null statistical hypothesis of the absence of differences and connections was rejected at p˂0.05.Results. The average correlation coefficient of oncotic pressure was 0.94 for total protein and 0.90 for albumin. Measurement of colloidal osmotic pressure showed a significant increase in pressure in each of the postdialysis samples. The hydrodynamic radius of the albumin peak for the predialysis sample is significantly higher, which may indicate a change in the sorption properties of the albumin surface.Conclusion. The calculation of oncotic pressure by the concentration of total protein, as a rule, provides clinical needs, however, with a significant concentration of toxins, clinical situations are possible in which a moderate decrease in the concentration of the "total protein" of the blood is detected, hence the main oncotic component – albumin is noted but there is a development pronounced edematous syndrome due to a significant decrease in oncotic pressure as a result of a conformational change in albumin molecules. In such situations, it is necessary to directly determine the oncotic pressure of the blood.

Stem cells therapies offer a promising approach in translational oncology, as well as in regenerative medicine due to the tropism of these cells to the damage site. To track the distribution of stem cells, the latter could be labeled by MRI-sensitive superparamagnetic (SPM) iron oxide nanoparticles. In the current study, magnetic properties of the magnetic nanoparticles (MNPs) incorporated into the bone marrow-derived fetal mesenchymal stem cells (FetMSCs) were evaluated employing nonlinear magnetic response measurements. Synthesized dextran-coated iron oxide nanoparticles were additionally characterized by X-ray diffraction, transmission electron microscopy, and dynamic light scattering. The MNP uptake by the FetMSCs 24 h following coincubation was studied by longitudinal nonlinear response to weak alternating magnetic field with registration of the second harmonic of magnetization. Subsequent data processing using a formalism based on the numerical solution of the Fokker–Planck kinetic equation allowed us to determine magnetic and dynamic parameters and the state of MNPs in the cells, as well as in the culture medium. It was found that MNPs formed aggregates in the culture medium; they were absorbed by the cells during coincubation. The aggregates exhibited SPM regime in the medium, and the parameters of the MNP aggregates remained virtually unchanged in the cells, indicating the preservation of the aggregation state of MNPs inside the cells. This implies also the preservation of the organic shell of the nanoparticles inside FetMSCs. The accumulation of MNPs by mesenchymal stem cells gradually increased with the concentration of MNPs. Thus, the study confirmed that the labeling of MSCs with MNPs is an effective method for subsequent cell tracking as incorporated nanoparticles retain their magnetic properties.

Features of the aggregation of С70 fullerene in an o-xylol have been revealed by observing the Doppler shift as a nondiffusive component in the dynamic light scattering spectra. The Doppler shift is...