Biophysical Bulletin

9th International conference “Nanobiophysics: fundamental and applied aspects”

M. V. Kosevich — 2026-06-25

9^th International conference “NANOBIOPHYSICS: Fundamental and Applied Aspects” – NBP-2025 took place on October 6-9, 2025 in Kharkiv, Ukraine, in online format, being organized by B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine and the Institute of Physics of the National Academy of Sciences of Ukraine. Previous conferences of the “NanoBioPhysics” series, launched in 2009, were organized on a biennial basis in Kharkiv and Kyiv in rotation. The conference brought together more than 100 participants from 13 countries: Ukraine, the Czech Republic, Estonia, Italy, France, Germany, Lithuania, Poland, the Slovak Republic, Spain, Sweden, the UK, and the USA. A total of 93 keynote, oral, and poster presentations were made. The goal of the conference was to discuss the urgent problems and new results achieved in the scientific field combining biophysics and nanotechnology, embracing nanobiohybrids formed by 1-D or 2-D nanomaterials with bioobjects, properties of biomolecules on nanoparticles and nanostructured surfaces, physical aspects of biomolecular nanosystems, theoretical calculations, computer modeling, and applied aspects of nanobiosystems. A special event within the framework of NBP-2025 was the round table on the topic “History of Biophysics in Kharkiv”, dedicated to the commemoration of outstanding scientists who formed the scientific school of molecular biophysics in the second half of the 20th century, which received recognition in Ukraine and abroad. Memories of them were shared by their students and followers, as well as employees of the biophysical departments of scientific institutions in Kharkiv. A book of abstracts based on NBP-2025 materials has been published.

Visualization and morphometrics of changes in cervical biotissues based on normalized spectral indices

Olexandr Roslyakov — 2026-06-25

Background: Modern visual diagnostics of precancerous and malignant lesions of the cervix requires increasing objectivity and accuracy through the use of physically based optical-spectral methods. Formation of quantitative spectral characteristics of structural changes in biotissue opens up new opportunities for differential assessment of the stage of pathology and construction of morpho-spectral screening scales.

Objectives: To develop a method for spectral visualization and analysis of morpho-optical changes in cervical biotissue based on normalized spectral indices (NSI) using a compact optical module and to determine key quantitative indicators sensitive to the stages of the oncological process.

Materials and Methods: To register spectral reflectance, a diagnostic module with a monochrome CMOS camera and a ring LED lighting system (450, 550, 630, 820 nm), supplemented with polarization filters, was used. NSI-map processing was carried out by calculating NSI-indexes and statistical parameters for 62 cervical images of patients of the main groups of pathologies with subsequent morphological verification.

Results: The NSI_630/820 index was the most sensitive to changes in tissue density and vascularization, its average value increased from 1.303 in inflammation to 1.528 in the case of adenocarcinoma. The increase in asymmetry and kurtosis in the NSI_530/820 profiles in the case of the transition from CIN to carcinoma indicates the likely formation of areas with increased optical heterogeneity. A structured classification of intervals of values of the main morpho-optical characteristics was formed, reflecting their changes within the pathological process.

Conclusions: The method of spectral-normalized visualization based on NSI indices allowed to quantitatively reflect morphological changes in the biotissue of the cervix. Indicators of changes in the spectral structure of the reflected optical signal, which correlate with the type of pathology, were established, and the effectiveness of the proposed approach for optical-physical differentiation of the stages of malignancy was proven.

Bacterial lysate of Lactobacillus rhamnosus DV suppresses bioluminescence of Photobacterium phosphoreum

Victor Martynyuk — 2026-06-25

Background: Recent studies on the lysate of Lactobacillus rhamnosus DV have demonstrated its antimicrobial and fungicidal activities. Classical microbiological methods for evaluating postbiotics and metabiotics are resource-intensive that need for new rapid and sensitive tests systems to assess their antimicrobial and antifungal properties.

Objectives: The aim of this work was to study the effects of the Lactobacillus rhamnosus DV lysate on the intensity of Photobacterium phosphoreum bioluminescence and to demonstrate the potential use of bacterial bioluminescence to determine the bacteriostatic activity of this postbiotic substance.

Materials and methods: The cell lysates of lactic acid bacterial strain L. rhamnosus DV were investigated, which were included in the Del-Immune V® dietary supplement produced by MirImmunoPharm LLC (Ukraine) in cooperation with Stellar Biotics, LLC (USA). The culture of P. phosphoreum IMV B-7071 was used in this study. Bioluminescence measurements were conducted using a digital photo-registration method. Bioluminescence was analyzed using cross-platform open-source software ImageJ (NIH) in brightness units in RGB color space.

Results: The bioluminescence intensity initially increased with population density during the first day, then faded despite the continued growth of cell density in the bacterial suspensions. The addition of Lactobacillus rhamnosus DV lysate significantly suppressed bioluminescence, reducing it to background levels within 24 hours, with the effect varying by concentration. The peak luminescence in control samples occurred at 18 hours, whereas in lysate-treated samples it shifted to 3–6 hours, depending on the lysate concentration.

Conclusions: The lysate of Lactobacillus rhamnosus DV causes a significant decrease in the growth rate of Photobacterium phosphoreum and strongly suppresses the intensity of their bioluminescence, the magnitude of which depends on the concentration of the lysate. This finding supports the use of bacterial luminescence as an effective way for evaluating the bacteriostatic activity of postbiotic substances against pathogenic and opportunistic microorganisms.

Regulatory effect of а synthetic opioid neuropeptid on protein homeostasis under cold stress conditions

N. M. Moisieieva — 2026-06-25

Background: Opioid neuropeptides are capable of regulating metabolic processes through the activation of specific opioid receptors, particularly under stress conditions. However, the mechanisms of their impact on protein metabolism under chronic cold stress (CCS) remain insufficiently studied. Given the importance of maintaining protein homeostasis under extreme conditions, investigating the role of neuropeptides in correcting protein profiles is of practical significance for developing new approaches to pharmacological adaptation.

Objective: To investigate changes in protein metabolism in the serum of guinea pigs under chronic cold stress, assess the protective effects of dalargin, and determine the role of the opioid system in regulating these processes.

Materials and Methods: The study involved guinea pigs exposed to CCS conditions. Changes in protein metabolism were assessed by measuring total protein, albumin, and globulins in the serum using standard biochemical methods. A synthetic leu-enkephalin analog (dalargin) was used as a corrective agent and administered subcutaneously at a dose of 100 µg/kg 30 min before CCS induction.

Results. In animals exposed to CCS, a statistically significant decrease in albumin levels and an increase in globulin levels were observed compared with intact values, which led to a disruption of the albumin–globulin ratio and indicated an imbalance in protein metabolism. Administration of dalargin contributed to normalization of the albumin–globulin ratio by restoring globulin and albumin levels in the blood of experimental animals, indicating stabilization of protein homeostasis and a protective effect of dalargin under conditions of CCS.

In addition, administration of dalargin reduced the accumulation of malondialdehyde (MDA) under conditions of cold stress, demonstrating antioxidant and cytoprotective effects and ensuring the maintenance of structural and functional integrity of tissues.

Conclusions. The study results suggest that dalargin is a promising agent for the pharmacological correction of metabolic disturbances induced by chronic cold stress, as it reduces MDA accumulation, exhibiting antioxidant and cytoprotective effects, and highlight the important role of the opioid neuropeptide system in the regulation of protein metabolism and maintenance of tissue structural integrity under extreme environmental conditions.

CDTE quantum dots–albumin bionanocomplex: genotoxic potential and bioimaging application in a Drosophila melanogaster model

N. Ia. Holub — 2026-06-25

Background: Research on semiconductor nanocrystals, known as quantum dots (QDs), and their applications in biomedical research, bioimaging, and diagnostics is evolving rapidly. Although CdTe QDs exhibit remarkable optical properties, their practical application is limited by their toxicity. As a result, research is ongoing to reduce the toxicity of QDs by coating them with inert shells or by forming complexes with biomolecules.

Objectives: Therefore, the aim of our study was to evaluate the genotoxic potential of the bionanocomplex of CdTe QDs with human serum albumin (HSA) as a safe and promising tool for fluorescence bioimaging in vivo, using D. melanogaster as a model.

Materials and Methods: CdTe QDs were obtained by chemical colloidal method in the aqueous phase and conjugated with HSA to create CdTe QDs-HSA bionanocomplex. The toxicity and genotoxicity of the QDs were evaluated in relevant tests on the D. melanogaster Oregon R strain. To visualize of QDs a fluorescence microscopy was applied. The data were subjected to statistical analysis, with differences deemed significant at p<0.05.

Results and Discussions: It was established that bionanocomplexes, similar to CdTe QDs, penetrated the germline cells, and were transferred to the eggs and larvae, as confirmed by histological preparations. In the muscles of the imago, rare CdTe QDs and their HSA conjugates were detected. The tested QDs types did not cause toxicity in adults after a 3-day exposure period, nor did they decrease their reproductive capacity or cause a genotoxic effect in the DLM test at the embryonic stage. Upon larval feeding, both types of QDs exhibited a teratogenic effect. Unlike CdTe QDs, the bionanocomplex induced phenotypic anomalies in imagos at a significantly lower frequency (2.3 times) and did not cause a reduction in their eclosion compared to the control group (p>0.05).

Conclusion: It was demonstrated that neither HSA-CdTe QDs nor CdTe QDs exhibit genotoxic effects at the embryonic stage. In contrast to CdTe QDs, the bionanocomplex does not cause reproductive toxicity, has significantly lower teratogenic effect, and a toxic impact on the post-embryonic developmental stages. These advantages suggest that HSA-CdTe QDs can be regarded as a relatively safe and promising tool for fluorescence bioimaging in vitro and in vivo applications in model organisms. However, their use in vivo in humans is not recommended.

Biomechanical and biochemical characteristics of musculus soleus contraction in obese rats

D. M. Nozdrenko — 2026-06-25

Background: Obesity is accompanied by complex metabolic disorders that significantly affect skeletal muscle physiology, including contractile activity and fatigue resistance. However, the mechanisms linking obesity to altered muscle function remain insufficiently characterized.

Objectives: The present study aimed to evaluate the impact of obesity on the biomechanical parameters of musculus soleus contraction in rats under fatigue conditions. In parallel, blood levels of creatinine, creatine phosphokinase (CPK), and lactate dehydrogenase (LDH) were measured to assess the relationship between metabolic alterations and neuromuscular dysfunction associated with obesity.

Materials and methods: Experiments were conducted on male white non-linear rats divided into control and high-calorie diet groups. The musculus soleus contraction force was recorded using strain gauges attached to the muscle tendons. Electrical stimulation of the L4-L5 efferents was performed with 2 ms impulses at 1 Hz, generated through platinum electrodes controlled by an ADC-DAC system. Muscle fatigue was induced by three stimulation series separated by 5 min rest intervals. The maximum contraction force, time to decrease muscle contraction force by 25% and 50% of the initial level and muscle force impulse were determined. Blood levels of creatinine, CPK, and LDH were measured by commercial kits.

Results: The findings have shown that obesity cause a significant suppression of the contractile activity of rat musculus soleus. The concentrations of creatinine, CPK, and LDH in the blood of obese rats increased, indicating impaired neuromuscular function and insufficient recovery during repeated stimulation. These alterations reflect obesity-induced dysfunction in muscle energy metabolism and contractile mechanisms.

Conclusions: Obesity causes pronounced suppression of the contractile activity of musculus soleus and disrupts neuromuscular homeostasis, as evidenced by both biomechanical and biochemical markers. The findings contribute to understanding the pathophysiological basis of muscle fatigue in obesity and may support diagnostics of obesity-related muscular dysfunction.

Computational modeling of selected phytochemicals from Reevesia formosana: mechanistic insights into their potential against lung cancer

Hung Duc Nguyen — 2026-06-25

Background: Lung cancer remains a dominant cause of cancer mortality, and impaired apoptosis mediated by anti-apoptotic Bcl-2 family proteins contributes to persistence and treatment resistance. Phytochemicals from Reevesia formosana display reported anti-NSCLC (Non-Small Cell Lung Cancer) activity, yet target-level mechanisms remain incompletely defined.

Objectives: To prioritize Reevesia formosana phytochemicals as putative Bcl-2 (PDB ID: 6GL8) inhibitors and to derive mechanistic insight through multiscale computation.

Materials and methods: Six phytochemicals and the reference Tivantinib were docked to 6GL8, and the top candidate (CPD1) was evaluated by 100 ns molecular dynamics simulations alongside Tivantinib. MMGBSA binding free energies were computed from 125 snapshots spanning 20-100 ns. ADMET properties were predicted using pkCSM. Frontier-orbital and global reactivity descriptors were obtained by DFT.

Results: Docking ranked CPD1 highest (-10.15 kcal/mol) relative to Tivantinib (-8.83 kcal/mol), with hydrogen bonding to Tyr108 and Arg129 and extensive pocket complementarity. MD trajectories indicated a more confined CPD1-6GL8 complex (RMSD mainly 0.18–0.22 nm) than Tivantinib-6GL8 (0.21–0.26 nm, occasional 0.27-0.28 nm), with comparable compactness (Rg of 1.44 nm) and bounded SASA. Hydrogen-bond counts supported intermittent polar anchoring for CPD1 (0-3) and higher early sampling for Tivantinib. MMGBSA favored CPD1 (ΔTOTAL -32.87 ± 4.28 kcal/mol) over Tivantinib (-17.27 ± 2.81 kcal/mol), supported by stronger ΔVDWAALS (-40.76 vs -31.34 kcal/mol) and a smaller ΔG_SOLV (20.28 vs 24.14 kcal/mol). ADMET prediction indicated high intestinal absorption with limited solubility, restricted BBB/CNS permeability, fewer CYP inhibition flags, and no hepatotoxicity alert for CPD1, while hERG II inhibition was flagged for both ligands. DFT showed similar EHOMO (eV) but a narrower ΔE (eV) and higher ω (eV) for CPD1 than for Tivantinib.

Conclusions: Integrated modeling prioritizes CPD1 as a Bcl-2-targeting scaffold for lung cancer-relevant studies, supporting structure-guided optimization and experimental verification.

3D models of proteins and conservative G-quadruplexes in the genome of porcine circovirus

O. Yu. Limanskaya — 2026-06-25

Background: Non-canonical structures formed in nucleic acid molecules, which include, in particular, multihelical connections 3WJs (three-way junctions), quadruplexes (G4s), are regulatory elements that affect the functioning of the genome. Building 3D models of these structures and pathogen proteins is the first step in understanding their functions. AlphaFold Protein Structure Database was created by Google DeepMind together with EMBL and it contains more than 241 million protein structures. 3D models of porcine circovirus type 3 (PCV-3) proteins have not been identified in this database.

The objective was to identify and characterize potential G4s and 3WJs in the PCV-3 genome, to build 3D

models of PCV-3 proteins.

Materials and Methods: 1138 PCV-3 isolates with complete genomes from GenBank were applied for phylogenetic analysis by MEGA12 software. The BioEdit software was used to construct entropy plots; the QGRS Mapper program was used to search for G4s motifs and determination of their G-scores; the BLAST software was used to search for 100% nucleotide sequence identity. 3D models of proteins and G4s were designed by AlphaFold 3 artificial intelligence.

Results: 4 conserved perfect G4s were identified in the PCV-3 genome, which are formed by three tetrads and confirmed by designing their 3D models. The determined G4s sequences are conservative structural motifs, since the number of PCV-3 isolates in GenBank with G4s in the genome is over 1000. 3D models of G4s the formation of one of which was experimentally determined in the genome of the hepatitis B virus were used as a control of the correctness of these models design. 3D models of the replicase and capsid protein were designed for the two evolutionarily most distant PCV-3 isolates, which were determined from phylogenetic trees based on the cap and rep genes, and the features of their structures were established. 3WJs were not identified in the PCV-3 genome.

Conclusions: 3D models of the replicase, capsid protein of porcine circovirus type 3 as well as four conservative G4s, which are formed by three G-tetrads, were obtained. Increasing the length of the fragments flanking G4s does not prevent their folding, which indicates the importance of these G-rich motifs in the PCV-3 life cycle. The existence of G4s with three tetrads in PCV-3 genome, in contrast to two-tetrad G4s in HBV, in the composition of not only aptamers, but also in molecules of increased length was confirmed by AlphaFold 3.

Improving the efficiency of spine region segmentation using an ensemble of pre-trained neural networks

V. D. Koniukhov — 2026-06-25

Background: The accuracy of segmentation of vertebrae in X-ray images is critical for clinical decisions as the manual method is laborious. The use of deep learning is complicated by low contrast, noise, and patient position artifacts. These negative factors make a single neural network unreliable. Thus, to improve the accuracy and efficiency of segmentation, regardless of the quality of X-ray images, there is a need for an ensemble of neural networks that compensates for the individual shortcomings of the models by aggregating their results.

Objectives: Increasing the accuracy and efficiency of segmentation of a spinal region consisting of four vertebrae (Th8, Th9, Th10, Th11) in X-ray images by using an ensemble of pre-trained neural networks.

Materials and methods: Two datasets were used for the experiments: the first set with 183 images was distributed in the ratio of 70% / 10% / 20% for training, validation, and testing, in turn, the second set of 58 images was used exclusively for the final assessment of the generalization ability of the ensemble on new data. In the process of research, segmentation accuracy with and without augmentation was first compared, after which the 10 best from the initial 20 neural networks were selected for further use, and five ensemble algorithms were used for mask aggregation.

Results: For the ensemble of pre-trained neural networks, the best result was shown by soft voting. Comparing the obtained result with the results presented by Koniukhov et al. (2024), the improvement was 3.06%. This indicator clearly confirms the effectiveness of using pre-trained networks for segmentation of the spine area.

Conclusions: Soft voting for an ensemble of pre-trained neural networks demonstrated the greatest improvement in segmentation accuracy compared to other methods. Aggregating knowledge from 10 models successfully eliminated the limitations of individual models. The use of an ensemble of pre-trained neural networks improved segmentation accuracy for both the test data from the first dataset and the data from the second dataset. Such results confirm the feasibility of applying the proposed ensemble-based approach to chest X-ray radiographs for vertebrae segmentation in medical imaging tasks.

Biophysics Week 2026. Biophysics in Ukraine: human energy and willpower in science and education during the wartime

V. S. Martynyuk — 2026-06-25

In March 2026, Ukraine hosted the second annual Biophysics Week — an international event held as part of the global initiative of the American Biophysical Society. This year, the event took on a nationwide scale, with the active participation of the Kyiv, Kharkiv, Lviv, and Zakarpattia branches of the Ukrainian Biophysical Society (UBS), along with leading universities and research institutions of the National Academy of Sciences of Ukraine. Over four days (March 25–28), scientists and young researchers presented reports spanning a broad range of topics, including molecular biophysics, nanotechnology, neural interfaces, bioinformatics, and artificial intelligence applications in biomedicine. Special emphasis was placed on the resilience of the scientific community under wartime conditions, the promotion of biophysics among young people, and the expansion of international collaboration. The strategic priorities of the UBS were defined as engaging youth — in particular through the Junior Academy of Sciences of Ukraine — and strengthening international scientific ties.