A new hybrid composite has been synthesized from partially unzipped multi-walled carbon nanotubes and graphite-like carbon nitride. This composite was thermochemically synthesized from urea and melamine with partially unzipped carbon nanotubes obtained by electrochemical synthesis. The resulting hybrid composite was characterized by X-ray diffraction, selected area electron diffraction, transmission electron microscopy and Fourier-transform infrared and Raman spectroscopy. These methods have proven the production of a hybrid composite of partially unzipped multi-walled carbon nanotubes and graphite-like carbon nitride. As evident from the voltammograms, the hybrid composite material exhibits the highest activity compared to the original components such as g-C3N4 and unzipped multi-walled carbon nanotubes. Electrochemical studies have demonstrated that the resulting hybrid composite is a promising material for use as a metal-free catalyst in oxygen electrodes for fuel cells, with performance characteristics approaching those of Pt-based oxygen electrodes. The resulting composites remained stable in operation for six months as an oxygen electrode in a fuel half-cell.

Background: Microscopy is a key tool in biophysical research for visualizing living cells' morphology, structure, and dynamic processes. Depending on the specific research goals, various optical and electron microscopy techniques can be applied, each offering unique benefits. Determining the structural features of the cytoskeleton, nucleus, and membrane of circulating tumor cells in the model Lewis lung carcinoma (LLC) is an important biophysical and biological task, as it will allow identifying targets for antitumor and antimetastatic therapy, as well as investigating the mechanisms of action of antitumor drugs. However, comprehensive multimodal imaging of such cells — particularly under non-adherent conditions — remains limited in the literature due to the difficulty of working with such models. Objectives: This study aimed to visualize Lewis lung carcinoma (LLC) cells cultured under de-adhesive conditions using various microscopy techniques for their characterization and to examine the cancer cells' structure and functionality. The goal was to evaluate each method's individual capabilities and combined strengths in revealing cellular morphology, internal structure, and nanoparticle interactions. Materials and Methods: LLC cells were obtained from the National Bank of Cell Lines and Tumor Strains of the IEPOR (NAS of Ukraine) and cultured in RPMI-1640 medium under conditions of de-adhesive growth. Imaging was performed using inverted optical microscopy (Euromex Oxion), fluorescence and confocal microscopy (Carl Zeiss LSM 510) with F-actin (Alexa Fluor 488-phalloidin) and nuclear (Hoechst 33342) staining, and label-free Coherent Anti-Stokes Raman Scattering (CARS) microscopy (Leica TCS SP8). Scanning electron microscopy (TESCAN MIRA3 LMU) was used for high-resolution surface imaging. 2D-MoS₂ nanoparticles, as well as 2D-MoS₂ and doxorubicin simultaneously, were applied to investigate nanoparticle-mediated labeling and cellular uptake. Results: A comparative analysis of multiple imaging modalities — including optical, fluorescence, confocal, CARS, and SEM — was applied to Lewis lung carcinoma (LLC) cells. Fluorescence microscopy with specific fluorophores made it possible to analyze the size and properties of actin fibers and showed that nuclei occupy most of the deadhesive cells. Electron microscopy revealed numerous filopodia on the cell surface. CARS showed the presence of lipid droplets in the cells. Conclusions: Each microscopy method provided complementary insights into cell morphology, cytoskeletal organization, lipid content, and surface ultrastructure. Nanoparticles demonstrated high utility as dual imaging and therapeutic agents. This work represents the first detailed SEM study of non-adherent LLC cells and highlights the potential of integrated multimodal imaging for studying circulating tumor cell models.

Trace metal Cu and carbonaceous airborn particulate matter (PM) are dangerous neuropollutants. Here, the ability of Cu2+ to modulate the neurotoxicity caused by water-suspended wood smoke PM preparations (SPs) and vice versa was examined using presynaptic rat cortex nerve terminals. Interaction of Cu2+ and SPs, changes of particle size and surface properties were shown in the presence of Cu2+ using microscopy, DLS, and IR spectroscopy. In nerve terminals, Cu2+ and SPs per se elevated the ambient levels of excitatory and inhibitory neurotransmitters L-[14C]glutamate and [3H]GABA, respectively. During combined application, Cu2+ significantly enhanced a SPs-induced increase in the ambient levels of both neurotransmitters, thereby demonstrating a cumulative synergistic effect and significant interference in the neurotoxic threat associated with Cu2+and SPs. In fluorimetric measurements, Cu2+ and SPs also demonstrated cumulative synergistic effects on the membrane potential, mitochondrial potential, synaptic vesicle acidification and ROS generation. Therefore, synergistic effects of Cu2+ and SPs on the most crucial presynaptic characteristics and neurohazard of multiple pollutants through excitatory/inhibitory imbalance, disruption of the membrane and mitochondrial potential, vesicle acidification and ROS generation were revealed. Increased expansion and burden of neuropathology may result from underestimation of synergistic interference of the neurotoxic effects of Cu2+ and carbonaceous smoke PM.

Electric conduction mechanisms are studied in the pressed nanoflake powder of the molybdenum-disulfide-oxide (MoSxOy) depending on their content and structure. The MoSxOy nanoflakes were prepared by reaction of (NH4)6Mo7O24 with thiourea in aqueous solution followed by aerial oxidation. The sintered nanoflakes are 10-20 nm thick and self-assembled in the "nanoflower"-shape aggregates forming powder particles. The chemical composition and structure of the powders were studied by XPS, EDS and Raman spectroscopy, which show that the powders have different chemical composition and structure depending on the preparation conditions. These studies revealed the existence of different forms of MoS2 and its oxides in the powders. These features are impactful on electric transport properties. The current-voltage (I-V) curves of the pressed MoSxOy nanoflakes reveal hysteresis-like behavior; at that the loop width depends on the chemical composition and structure. The negative differential conductivity is observed for the highest content of Mo in oxide/sulfoxide form. The I-V curves of all MoSxOy nanoflake samples manifest the three-state resistive switching and the long-lasting transient charge/discharge on switching "on/off" the voltage across the sample, which evidences the role of interface charges in their conductivity. To describe theoretically the observed I-V curves, polar and electric-transport properties of the pressed MoSxOy nanoflakes, the Landau-Cahn-Hilliard approach considering flexo-chemical field has been used. The revealed experimentally and explained theoretically features of resistive switching and charge accumulation look promising for applications in memristors and high-performance supercapacitors.

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Doxorubicin (DOX) interaction with 2D boron nitride (BN) nanoparticles was studied experimentally and theoretically. The BN nanoparticles, namely nanoflakes, were obtained by direct liquid-phase exfoliation via preliminary stratification in a planetary ball mill from massive hexagonal BN. 2D BN nanoparticles and DOX/BN composites were characterized using visible steady-state, time-resolved fluorescence, FTIR and Raman spectroscopy, Coherent Anti-Stokes Raman Scattering (CARS) microscopy and density functional theory (DFT). The BN nanoflakes from 2–3 layers up to hundred nm in lateral direction possessed crystalline properties that formed the DOX/BN composites with fluorescence in the range of 520–750 nm that can be used in DOX detecting. The calculations revealed a notable electron transfer between the BN monolayer and the DOX molecule, which, however, is partly offset by the redistribution of charge within the monolayer. The energy of interaction of the BN with DOX was estimated as 1.96 eV, indicating that the DOX/BN composite formation is an exothermic process. The Fluorescence quenching of DOX/BN occurs with increased BN nanoparticle concentration. The optimal concentration for composite formation was chosen. In CARS imaging of the Lewis lung carcinoma cells after treatment with DOX/BN, brightly luminous points are observed inside the cells, indicating the accumulation of DOX/BN composites that can be used in bioimaging and theranostics.

Hostilities are accompanied by extremely enhanced air pollution with particulate matter (PM) which was exactly shown in Ukraine, where increased PM2.5 (the size less than 2.5 μm) correlated with war activities [R. Zalakeviciute et al., Sustainability 14(21), 13832 (2022)]. Drastic increases in PM2.5 pollution from bombing and structural fires raise additional health concerns. Also, the widest spread of war-associated metal pollutants are copper and iron [Metal Pollutants Associated with War (2023, November)] which are neurotoxic [B. Tarnacka et al., Int. J. Mol. Sci. 22(15), 7820 (2021)]. Calculations have revealed that Ukrainian regions are highly contaminated with copper and iron that in turn become bioavailable. Neurological disorders are the most common cause of disability/death and their increase is linked to air pollution with PM, which targets the nervous system triggering the development of neuropathology as shown in the epidemiological data of the Lancet Commission [P. J. Landrigan et al., Lancet 391, 462 (2018)]. Airborne PM can travel across state boundaries, oceans, and continents, and so disperses globally causing hazards to human health not only in Ukraine but also worldwide. Our hypothesis [T. Borisova, N. Krisanova, O. Gnatiuk, V. Boyko, and G. Dovbeshko, Project “War-derived air pollution nanohybrids composed of carbon-containing smoke nanoparticles and metal compounds: FTIR/Raman spectroscopic, fluorescent and membrane-active properties, their potential neurotoxicity and its prevention”, PAN.BFB.S.BWZ.380.022.2023] is that the neurotoxic potential of abandoned war-associated carbonaceous smoke nanoparticles can be significantly enhanced by copper and iron compounds during their combined release to the environment during bombing and fires. Moreover, they can form nanohybrids during interaction in the environment. This hypothesis is based on our recent experimental data regarding neurotoxic features of smoke PM from wood and plastics and their capability to interact with other pollutants [A. Borysov et al., Environ. Pollut. 263, 114502 (2020), A. Pastukhov et al., Sci. Rep. 13, 17771 (2023), T. Borisova, Environmental Nanoparticles: Focus on Multipollutant Strategy for Environmental Quality and Health Risk Estimations, Chapter in: Biomedical Nanomaterials, R. S. Stoika (ed.) (2021), pp. 305–321, T. Borisova and S. Komisarenko Environ Sci. Pollut. Res. 28(30), 40371 (2021)]. It is an urgent necessity to analyze the molecular structure and membrane-active properties of war-derived polluted nanohybrids composed of carbonaceous smoke nanoparticles, copper, and iron; to assess their potential neurotoxicity and to find a way of neuroprotection. Knowledge about the capability of different war-derived PM to form environmental nanohybrids with war-associated pollutant copper and iron, and their spectroscopic, fluorescent, and membrane-active features can be applicable in environmental monitoring. Potential neurotoxicity data of war-derived nanohybrids can be used for the prognosis of neurological symptoms and the development of possible ways for neuroprotection.

The study of large biomolecules, in particular DNA, is of practical interest. Marker bands of the Raman spectrum of DNA provide information about the conformational state and structure of the macromolecule. At the same time, when dealing with biological experiments, a small amount of DNA is available, which is why it is important to enhance the signal from DNA and find the proper substrate. However, it is difficult to enhance Raman spectra for large molecules as DNA without functionalization that could introduce changes in the DNA structure. In this work, a conventional substrate as CaF2 and a photonic crystal as a substrate with enhancer signal property and without DNA functionalization were applied. The factor of enhancement for DNA from salmon testes was reached up to 10 without Raman spectra distortion. The Raman spectral bands on different types of substrates are analyzed and compared.

Vacuum-sublimation cryogenic deposition (VS-CD) method is successfully applied to produce fullerene water colloidal solution (FWCS): the melting of the solid phase of the mixture obtained by joint condensation of C60 fullerene and water vapors onto a surface cooled with liquid nitrogen results in formation of a stable colloidal solution. The results of the FWCS characterization by means of Raman, IR, and UV-Vis spectroscopy and their comparison with known literature data on hydrated fullerenes give the authors an opportunity to make conclusion that the FWCS contains C60@{H2O}n complexes of hydrated C60 fullerene. Transmission electron microscopy shows that the VS-CD-produced material contains predominantly small C60 clusters of about 2–5 nm size, while mass spectrometry with laser desorption/ionization has demonstrated the presence of pure fullerene C60 and the absence of any products of its transformation. The performed analysis reveals a close similarity of the stable C60@{H2O}n complexes generated by VS-CD with the previously known highly hydrophilic hydrated fullerene obtained by ultrasonication method.

By sintering ZnO powder mixed with ethylene glycol, electrodes on a glass substrate with a conductive SnO2 layer were obtained. In parallel, Ti/TiO2 electrodes were obtained by anodizing a titanium foil. Electrodes based on ZnO and TiO2 were sensitized to visible light with a cationic polymethine dye. The analysis of the photoelectrochemical characteristics of the obtained electrodes showed that the dye-sensitized ZnO films in the wavelength range of 450–650 nm have a photocurrent quantum yield two-fold higher compared with TiO2. In this way, a hybrid dye-ZnO structure sensitive to visible light was formed, which can be used for the photoelectrochemical cells for solar energy conversion, as well as for the detection of DNA and proteins in biological sensors.

Metastasis in oncological diseases remains one of the main reasons for negative prognosis regarding treatment. Any new data on the biophysical and biochemical characteristics of circulating metastatic cells will help to develop a concept for antimetastatic therapy. In this study, we found a number of differences in the spectroscopic and morphological features of circulating metastatic cells. FT-IR and Raman spectra cultivated by adhesive and de-adhesive methods (with the latter used as a model for metastatic cells) have shown spectroscopic features, namely in FT-IR spectra in the region of CH stretching vibrations, which are associated with structural rearrangements in the cell membrane, as well as changes in the intensity and position of the PO2− group vibration bands correlated with proliferative activity. The spectral features in the regions of OH stretching and Amide I vibrations as well as other spectral markers of the metastatic cells grown under different cultivation conditions were derived. Raman spectra showed a redistribution of the amino acid Tyr/Trp (tryptophan to tyrosine) ratio and in Tyr doublet intensity in the region of 500–900 cm−1, as well as varying glycogen levels in different cells. The spectroscopic markers are in accordance with biochemical data. CARS and confocal optical microscopy were applied to determine the state of the cells and the F-actin expression level, which turned out to be higher for adhesive cells in comparison with de-adhesive cells. The shape and the morphological properties of the cells differ drastically. The correlation of vibrational markers with biochemical data and the cytofluorometric method was discussed.

A new type of metal-free oxygen electrode has been proposed. Its distinguishing feature is applying as an active layer nanodispersed graphitic carbon nitride with electrocatalytic properties controlled by synthesis conditions. Optimal conditions of thermochemical synthesis of g-C3N4 by a heat treatment of a solid mixture of melamine precursor and nitrogen-rich urea additive have been defined. The obtained layered g-C3N4 has been characterized by XRD, selected area electron diffraction, TEM and FTIR. An investigation of the electrocatalytic characteristics of oxygen electrodes has been carried out in a fuel half-cell with alkaline electrolyte. The electrochemical characteristics of the obtained g-C3N4 material with melamine-to-urea ratio 1:2 have been shown to be close to those of platinum electrodes. Electrochemical studies have shown that the obtained carbon nitride is a promising material as metal-free catalyst for oxygen electrodes of fuel cells The long-term testing of produced materials confirmed that they were stable over six months.

Adhesion disease is a common complication of abdominal operations, which is often manifested by acute adhesion obstruction of the intestine with a high rate of recurrence on surgical treatment. Mechanical damage to the peritoneum, which leads to uncontrolled leakage of blood from the damaged vessels and the formation of blood clots with the loss of fibrin at the site of damage, is recognized as the leading trigger of adhesion disease.The stability of the formed adhesions, their ability to grow and regenerate are in conflict with the known data on the mechanisms of the hemostasis system. The latter, as is known, consists of two divergent activation cascades, which ensure the blocking of hemorrhage in case of damage to vessels due to the formation of a fibrin clot with its subsequent splitting into large soluble blocks.An imbalance between the coagulation and fibrinolytic links of the hemostasis system causes various functional complications. The formation of adhesions can be considered as an extreme example of such an imbalance. This leads to the search for the reasons for the inefficiency of the fibrinolytic system in relation to fibrin deposits in adhesions. The aim of the work: study of the structure of fibrin deposits in adhesions using histological methods and infrared spectroscopy. Results and discussion. It is shown that adhesions of the peritoneum are a complex structure formed by protein and cellular components. The protein component is formed by fibrin and collagen, and the difference in the structure of these proteins from the native one with a pronounced content of β-structured aggregates is noted. The cellular component is mainly represented by fibroblasts - the main cells of connective tissue that synthesize collagen, elastin, proteoglycans and glycoproteins. Such composition ensures resistance of adhesions to fibrinolysis and their ability to regenerate.

The sheet samples of thermally exfoliated graphite (TEG)–carbon nanotubes (CNT) composites (TEG-CNT-cs) were obtained by persulphate oxidation using chemical (CO) and electrochemical (anode) oxidation (ECAO). Electron microscopy reveals multi-layered structures of few-layer graphene nanosheets with folded and tubular-like fragments. The effective thermal diffusivity values were estimated by nonstationary photo-pyroelectric thermophysical characterization using the heat pulse and thermowave modulation methods. Comparison with other carbon (C-) based thermal management materials shows that TEG-CNT-cs exhibit thermal diffusivity, effusivity, and conductivity comparable with those of actual C–polymer- and C–C-composites. For TEG-CNT-cs, evaluated values of phonon mean free path (MFP) and relaxation time (RT) are in the ranges estimated for defective graphene. The values of diffusivity and effusivity, MFP, and RT are lower for denser TEG-CNT-cs obtained by ECAO and are higher for less dense TEG-CNT-cs obtained by CO. The obtained diffusivity and effusivity values designate TEG-CNT-cs as suitable thermal management materials.

The purpose of the work is to investigate changes in survival rates, proliferative potential, glucose metabolism and redox metabolism in metastatically active cells of Lewis lung carcinoma during the transition from anchorage-dependent to anchorage-independent growth. It was shown that the transition from anchorage-dependent growth to anchorage-independent growth is accompanied by a considerable intensification of glucose consumption rate. An increase in glucose consumption during anchorage-independent growth does not cause stimulation of proliferative activity. An increase in glucose consumption and a decrease in proliferative activity indicates a redirection of glucose to the synthesis of enzymes of the antioxidant system in order to prevent apoptotic death during anchorage-independent growth.

Fourier-transform infrared (FTIR) spectral changes for model membranes (liposomes) consisting of three lipids, 1,2-dioleoyl-sn-glycero-3-phosphocholine, cardiolipin, and cholesterol, were studied under the application of 2D-WS2 nanoparticles during the process of liposome preparation and after it. We got up to a 30% increase in the intensity of lipid vibrational bands for PO2-stretching symmetrical vibrations and 10% for CH2- and OH-stretching vibrations in the case of liposomes prepared without nanoparticles and after their subsequent addition. The changes in FTIR spectra are explained by the local electrical field appearing in liposomes, which are placed in the vicinity of the curved 2D-WS2 nanoparticles. Quantum-chemical calculations showed negligibly small changes in electron density and Bader charges (less than 0.02 e) of the single-layer 2D-WS2 corrugated up to 10%. Inhomogeneous charge distribution at the liposome surface can enhance the electron density of the 2D-WS2 nanoparticles leading to the redistribution of FTIR spectra intensity for liposomes near the 2D-WS2 nanoparticles.

The broadband emission in the range from Vis to NIR (known as LIWE or laser-induced white emission) was previously discovered for samples under NIR excitation in vacuum. Despite the recent progress in understanding this phenomenon, there is no proper model which can explain all features of this effect. The aim of the present paper is to expand the current knowledge and to develop an appropriate model of LIWE. Studying the properties of LIWE for MoS2 and WS2, we have revealed the similarities in LIWE for MoS2, WS2, and graphene, namely, their emission spectra cover broad regions, power dependences exhibit the same slope, and emission curves have the same shapes. The multiphoton ionization model was proposed for explanation of LIWE phenomena in all these materials.

Tremendous deposits of disposable medical facemask waste after the COVID-19 pandemic require improvement of waste management practice according to WHO report 2022, moreover facemasks are still in use around the world to protect against numerous airborne infections. Here, water-suspended smoke preparations from the combustion of disposable medical facemasks (polypropylene fibers) were collected; size, zeta potential, surface groups of smoke particulate matter were determined by dynamic light scattering, FTIR and Raman spectroscopy, and their optical properties were characterized. Neurochemical study using nerve terminals isolated from rat cortex revealed a significant decrease in the initial rate of the uptake/accumulation of excitatory and inhibitory neurotransmitters, L-[14C]glutamate and [3H]GABA, and exocytotic release, and also an increase in the extracellular level of these neurotransmitters. Fluorescent measurements revealed that ROS generation induced by hydrogen peroxide and glutamate receptor agonist kainate decreased in nerve terminals. A decrease in the membrane potential of nerve terminals and isolated neurons, the mitochondrial potential and synaptic vesicle acidification was also shown. Therefore, accidental or intentional utilization of disposable medical facemask waste by combustion results in the release of neuroactive ultrafine particulate matter to the environment, thereby contributing to plastic-associated pollution of air and water resources and neuropathology development and expansion.

У доповіді наведено результати проведених в Інституті фізики НАН України експериментальних і теоретичних досліджень з вивчення за допомогою методів спектрального аналізу та методів чисельного моделювання фізичних механізмів функціонування різних біологічних макромолекул (білки, нуклеїнові кислоти, ліпіди), надмолекулярних нанорозмірних біологічних систем (біологічні мембрани) та наноструктур (наноструктуровані поверхні та наночастинки), що містять біологічні молекули.