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Vol 70, No 1 (2025)
Molecular biophysics
Preparation and Properties of Iodine-Containing Polylactide Fibers
Abstract
Bioactive polylactide fibers with 6 wt% iodine content were produced using the crazing in liquid media. These fibers exhibited good mechanical properties, with an elastic modulus within the order of 3 GPa and strength of 125 MPa. It has been shown that iodine is uniformly distributed throughout the polymer material, forming nanoparticles with a size of 5−15 nm. It has been found that the degradation of iodine-containing polylactide fibers in a model medium of the PBS buffer at 37°C occurs quite quickly, and in 6 weeks the value of the molecular weight of the polymer decreases by almost ten times of magnitude to 9.4 kDa, and the dispersion increases to 5.5. In the presence of iodine-containing fibers, the phase of the inflammatory reaction is suppressed, and proliferative processes are stimulated during the experiment in vivo.
Biofizika. 2025;70(1):5-13
5-13
UV-Visible Light-Induced Luminescence Processes in Non-Aromatic Amino Acids Solution at Room Temperature
Abstract
We demonstrate for the first time that aqueous solutions of non-aromatic amino acids such as L-arginine hydrochloride, L-lysine hydrochloride and glycine can simultaneously emit fluorescence and afterglow upon excitation with UV-visible light at room temperature. The luminescence afterglow differs from conventional fluorescence by its weak intensity and long emission duration. The presence of short-lived and long-lived fluorescence in non-traditional luminophores indicates a dual nature of fluorescence and the existence of excited states of different natures. The detected correlation in the shape of short-lived and long-lived fluorescence spectra suggests that the luminescence afterglow corresponds to thermally activated delayed fluorescence arising through the mechanism of reconversion from the lowest triplet state T1 to the lowest singlet state S1. Further studies will help to shed light on the understanding of the biophysics of photoinduced processes in biological systems.
Biofizika. 2025;70(1):14-21
14-21
Complexation of Papain with Particles of Chitosan and Carboxymethylchitosan, Obtained in the Presence and in the Absence of Ascorbic Acid
Abstract
Particles of medium and high molecular weight chitosans and carboxymethylchitosans were obtained without and with the addition of ascorbic acid. Methods were developed to obtain complexes of these particles with the plant protease papain. It was found that the activity of papain complexes with particles of carboxymethyl chitosan is significantly higher compared to its complexes with particles of chitosan. At the same time, complexes with particles of chitosan and carboxymethyl chitosan obtained with the addition of ascorbic acid showed higher values of proteolytic activity than complexes with polysaccharide particles obtained without its addition. Using molecular docking, it was found that amino acid residues of papain interact with both chitosan and carboxymethyl chitosan mainly by forming hydrogen bonds and van der Waals interactions. In addition, ascorbic acid molecules and both types of polysaccharides interact with amino acid residues from the active site of papain – Cys25 and His159, which probably contributes to an increase in the activity and stability of the enzyme in complexes with particles of chitosan and carboxymethyl chitosan, including due to the fact that ascorbic acid prevents the oxidation of the thiol group of papain, which is responsible for the act of catalysis.
Biofizika. 2025;70(1):22-34
22-34
Computational Study of Polyligand Complexes of Aspirin with Human Serum Albumin Using Docking and Molecular Dynamics Methods
Abstract
An important feature of biochemical reactions of molecules is the possibility of binding of several ligands to a biomolecular target. This effect should be taken into account in the analysis of protein–ligand interactions and in the estimates of drug distribution in the living systems. This work describes molecular simulations of successive parallel steps of binding of two aspirin (As) molecules at the known binding sites 1–3 of human serum albumin with differing affinity. The experimental data on multiple binding of aspirin to albumin is inconclusive. Docking of aspirin anion As– to albumin predicts that stability of the complexes at the binding sites changes as 1 > 3 > 2. Molecular dynamics simulations have further shown that the complexes at site 3 are unstable. The free energies of ligand binding ΔGb have been calculated using extended linear interaction energies method with additional contributions of the entropy of ligand binding. The results have shown that the most probable reaction path corresponds to binding of As– at site 1 with ΔGb1= ‒8.2 kcal·mol–1 and after that to site 2 with ΔGb2= ‒4.5 kcal·mol–1. The calculated values of ΔGb agree with the known experimental data. The stoichiometry of the albumin–As–complexes is 2. Negative cooperative effect is found for binding of two As– molecules with albumin. The used molecular model and computational approaches can be further employed in the studies of binding of different medicinal molecules that are transported by serum albumin.
Biofizika. 2025;70(1):35-43
35-43
Ability to Assess the Bactericidal and Fungicidal Effect by Fluorescence of Proteins and Amino Acids
Abstract
When studying the antimicrobial effect of various physical factors, it is useful to monitor the changes occurring with a biological object. Proteins are the main components of living cells, so damage to the structure of proteins and their amino acids can be a critical factor responsible for the death of microorganisms. UV absorption spectra and fluorescence spectra for albumin, tyrosine and tryptophan after the action of pulsed radiation of hot plasma of the IR10 generator were studied. The fluorescence of model solutions of albumin, tyrosine and tryptophan was compared with the fungicidal effect of an aqueous suspension of Aspergillus niger micromycetes and the bactericidal effect of E. coli depending on the dose of pulsed radiation of hot plasma spark discharge. It has been established that a decrease in fluorescence yield correlates with fungicidal effects, so measurements of protein and amino acid fluorescence can be used to quickly assess the possibility of damage to biological objects. The bactericidal effect is much stronger than the fungicidal effect, which indicates the predominance of mechanisms that do not affect fluorescence.
Biofizika. 2025;70(1):44-50
44-50
Effects of Leu43Pro Mutation in the TPM1 Gene on the Structure and Properties of Cardiac Tropomyosin
Abstract
We investigated the effect of the Leu43Pro mutation in the TPM1 gene encoding the cardiac tropomyosin isoform on the structure and properties of the tropomyosin molecule. For this purpose, we obtained a recombinant tropomyosin preparation with the L43P amino acid substitution in both α-chains of the tropomyosin double superhelix, i.e. with the substitution of the canonical Leu43 residues by the non-canonical Pro residues, and studied the effect of this substitution on the structural and functional properties of tropomyosin. Circular dichroism spectroscopy showed that the L43P substitution significantly disrupts the α-helical structure of the tropomyosin molecule. Differential scanning calorimetry showed that this amino acid substitution causes serious changes in the domain structure of the tropomyosin molecule, leading to significant destabilization of the N-terminal part of the molecule. Measurements of the viscosity of tropomyosin solutions showed that the L43P substitution reduced the viscosity of tropomyosin by more than 7 times compared to the viscosity of the control wild type tropomyosin preparation. It was found, using the method of co-precipitation of tropomyosin with F-actin, that the L43P substitution significantly reduced the affinity of tropomyosin for F-actin. The data obtained clearly indicate that the L43P substitution in both α-chains of the double helix of the tropomyosin molecule significantly changes both the structure of the molecule and the functional properties of cardiac tropomyosin.
Biofizika. 2025;70(1):51-58
51-58
Cell biophysics
Regulation of Electron Transport in Chloroplasts: Induction Processes in the Leaves of Cucumis Genus
Abstract
In this work, we describe results of our study of electron transport in chloroplasts in situ (leaves) of two species of the Cucumis genus, shade-tolerant species С. sativus (cucumber) and light-loving species С. melo (melon), grown at high light (800–1000 μmol photons m−2 · s−1) or low light (50–125 μmol photons m−2 · s−1) conditions. The light-induced processes of electron transport were monitored by using the electron paramagnetic resonance (EPR) and optical methods (a difference signal from P700 + ), and the yield of chlorophyll a fluorescence. It has been demonstrated that the plants grown at high light reveal high rates of P700 photooxidation and fluorescence decrease, as compared to plants grown at low light. The data obtained are discussed in the context of electron transport regulation mechanisms in shade-tolerant and light-loving species of the Cucumis genus.
Biofizika. 2025;70(1):59-71
59-71
Stoichiometry of the Formation of Physiologically Active Cytochrome C Complexes with Cardiolipin
Abstract
The major goal of this work was to study the stoichiometry of the interaction of cytochrome C with tetraoleoyl- or tetramyristoyl-cardiolipin. Complexes of cytochrome C with phospholipid play one of the main roles in apoptotic processes. This study was conducted using fluorescently labeled phosphatidylcholine (BODIPY-PC). The fluorescence quenching of the BODIPY-PC probe after its interaction with cytochrome C was measured. Calculations of the fluorescence quenching results allowed us to determine the stoichiometry of the cytochrome C complexes formed with phospholipids. For complexes containing tetraoleoyl, stoichiometry corresponded to the ratio tetraoleoyl : cytochrome C equal to 25 ± 7, and for tetramyristoyl the ratio tetramyristoyl : cytochrome C – 7 ± 2. Obtained results may indicate a difference in the affinity of cytochrome C for saturated and unsaturated types of cardiolipin, despite the same electrostatic characteristics of the molecules. It can be expected that the discovered features of the interaction of cytochrome C with cardiolipin will eventually help determine the intensity and direction of apoptotic reactions.
Biofizika. 2025;70(1):72-77
72-77
Formation of Heterotetrameric Potassium Channels Kv1.1–Kv1.2 in Neuro-2a Cells: Analysis by the Förster Resonance Energy Transfer Technique
Abstract
The subunits of the voltage-gated potassium channels Kv1.1 and Kv1.2 can form both homo- and heterotetrameric channels in cells. This significantly affects the functional properties and localization of the formed Kv1 channels. Confocal microscopy based on Förster resonance energy transfer was used to study the formation of Kv1 channels during co-expression of subunits Kv1.1(S369T) and Kv1.2(S371T), fused with the fluorescent protein mKate2 and TagCFP, respectively, in murine neuroblastoma Neuro-2a cells. Due to mutation, these subunits provide enhanced transfer of Kv1 channels in plasma membrane. It was found that TagCFP-Kv1.1(S369T) and mKate2-Kv1.2(S371T) effectively form heterochannels that are localized both on the membrane and in the cytoplasm of cells. In the absence of the S369T mutation, heterochannels are not embedded in the membrane, which indicates the need for auxiliary factors for the transfer of native heterochannels into the cell membrane. In addition to heterochannels, homotetrameric channels are also formed in cells, but the effectiveness of the formation of heterochannels is much higher.
Biofizika. 2025;70(1):78-85
78-85
Properties of the Fluorescent Kv1.2 Channel Assembled from Concatemers of Alpha-Subunits
Abstract
α -Subunits of the potassium voltage-gated channel Kv1.2, whose function is to regulate neuronal conductivity in the central nervous system, form heterotetramers with α-subunits of related Kv1 channels, which differ in composition and stoichiometry. To study heterotetrameric channels in vitro, concatemers are constructed by sequentially connecting the Kv1 α-subunits. The method for constructing concatemers that allows one to reproduce the properties of native channels requires detailed study. In this work, concatemers (dimers) of Kv1.2 α-subunits (mKate2-Kv1.2-Kv1.2) labeled with the fluorescent protein mKate2 were constructed Kv and their expression was carried out in mouse neuroblastoma Neuro-2a cells. It was shown that the Kv1.2 channel assembled from concatemers is almost identical in its properties, namely, intracellular distribution, ability to integrate into the plasma membrane, efficiency of interaction with a peptide blocker, as well as in its electrophysiological characteristics, to the Kv1.2 channel based on monomeric α-subunits mKate2-Kv1.2.
Biofizika. 2025;70(1):86-92
86-92
Study of Functional Manifestations of Met23Leu Missense Mutation in the Auxiliary Subunit KCNE2 (Mirp1) of Cardiac Channel Kv11.1
Abstract
In the present study, we functionally analyzed a missense mutation c.67A>T (p.Met23Leu) in the KCNE2 potassium channel Kv11.1 complementary subunit gene identified in a patient with asymptomatic QT interval prolongation on electrocardiogram. We artificially introduced this substitution into the plasmid encoding the KCNE2 subunit and expressed the mutant gene in Chinese hamster ovary cells together with the wild-type Kv11.1 channel gene to evaluate the effect of the mutation on IK1 current parameters. We used a comprehen-sive approach including the study of the integrated IKr current using the patch-clamp method in a whole-cell configuration in potential fixation mode. The study showed that the c.67A>T mutation (p.Met23Leu) is realized in a gain-of-function type, but the current density carried by Kv11.1 channels is significantly reduced. Fluorescence microscopy showed impaired trafficking of a channel coexpressed with the mutant subunit to the cell surface. We applied molecular modeling to examine the location of the mutant subunit relative to the membrane.
Biofizika. 2025;70(1):93-103
93-103
Selenium as a Protector Against Hydrogen Peroxide Oxidative Degradation of Heme of Hemoglobin without the Glutathione Peroxidase Mechanism
Abstract
The protective effect of sodium selenite (Na2SeO3) on the oxidative degradation of hemoglobin induced by hydrogen peroxide (H2O2) was studied by recording the resulting two fluorescent products of heme breakdown (λex = 321 nm, λem = 460 nm) and (λex = 465 nm, λem = 525 nm). It has been established that sodium selenite (Na2SeO3) inhibits the development of oxidative modification of hemoglobin (depletion of oxyhemoglobin, accumulation of methemoglobin and ferrylhemoglobin), which is reflected in a noticeable 20–30% decrease in fluorescence peaks, reflecting the oxidative destruction of heme in the absence of the contribution of antiperoxide enzymes (catalase, glutathione peroxidase, peroxiredoxin-2) in Н2О2 utilization. This raises the question of the independent AO significance of selenium in hemoglobin, in its protection from peroxide effects without the GPX mechanism of Н2О2 utilization.
Biofizika. 2025;70(1):104-111
104-111
Size Characteristics and Mechanisms of Toxic Action of Selenium, Cobalt, and Silver Nanoparticles on Mitochondria of the Liver of Rats
Abstract
Nanosized materials are widely used in biomedical nanotechnologies, but the mechanisms of toxic effects of metal and non-metal nanoclusters remain unclear. The aim of this work is to evaluate the size characteristics and mechanisms of toxic action of silver, selenium, and cobalt nanoparticles at the level of isolated mitochondria. Using the laser ablation method, silver (rounded, ~10–20 nm and ~50 nm), cobalt (cubic and prismatic, ~100–200 nm), and selenium (spherical, ~20–30 nm and 135–180 nm) nanoparticles with different spectral characteristics and capable of forming conglomerates were obtained. Silver, cobalt, and selenium nanoparticles (0.1–10 μg/ml) effectively inhibited the respiratory activity of isolated rat liver mitochondria by disrupting the coupling of oxidation and phosphorylation, which was accompanied by a drop in the mitochondrial membrane potential. The uncoupling effect of nanoparticles may be associated with the transfer of electrons from the electron transport chain of mitochondria to the positively charged surface of nanoparticles and depends on the size and material of the nanoparticles.
Biofizika. 2025;70(1):112–121
112–121
Nitrosonium Cation as a Nitroprusside Constituent Determining Its Cytotoxicity
Abstract
It has been demonstrated that nitrosonium cation (NO+) transformation as a constituent of sodium nitroprusside into NO molecule under action of sodium dithionite as a strong reducer did not result in full supression of cytotoxic activity of nitroprusside solution as NO+ donor on the culture of MCF-7 tumour cells. As a matter of fact, NO molecules and Fe2+ ions released from SNP at this conditions formed dinitrosyl iron complexes with thiol-containing ligands (thiol-containing proteins or thiosulphate anions appeared from decomposed dithionite).The half of nitrosyl ligands in the complexes represented also as in nitroprusside in cytotoxic NO+ form. Nevertheless because the amount of dinitrosyl iron complexes was three times less than that of initial nitroprusside the cytotoxic effect of nitroprusside solution as NO+ donors sharply decreased under action of dithionite on nitroprusside.
Biofizika. 2025;70(1):122-128
122-128
Modifying Effect of Astaxanthin in Combination with Diethyldithiocarbamate on Proliferation of Mouse Neuroblastoma Cells N1E-115 (CLONE C-1300)
Abstract
The effect of astaxanthin, diethyldithiocarbamate and their combined application on cell proliferation was studied on mouse neuroblastoma culture N1E-115 (clone C-1300). There is evidence for the anti-cancer effect of astaxanthin in various tumour cell types. Diethyldithiocarbamates are used as additional drugs in chemotherapy. The use of non-toxic drug complexes is a new strategy for the treatment of cancer. We have shown that the action of diethyldithiocarbamate and astaxanthin both separately and in combination causes inhibition of proliferation and induction of differentiation of mouse neuroblastoma N1E-115 cells. Based on the results of Western blot analysis it was revealed that the combination of the drugs increased the expression of CHOP protein (marker of endoplasmic reticulum) and proapoptotic protein Bax, decreased the expression of anti-apoptotic protein Bcl-2, which may indicate the start of apoptotic cascade. Meanwhile, application of diethyldithiocarbamate alone caused a decrease in both Bax and Bcl-2 levels, but had no effect on CHOP protein expression. Apparently, astaxanthin modifies the effect of diethyldithiocarbamate when used together.
Biofizika. 2025;70(1):129-136
129-136
Complex systems biophysics
Thermal Processes Associated with Electrophoresis under Conditions of High Ionic Strength
Abstract
Temperature heterogeneity of the electrophoretic solution, dynamically changing during electrophoresis in the gel platform area, was demonstrated by us earlier. In order to understand the reasons for this effect, we used U-shaped inserts in the wells of the electrophoretic chamber, protruding above the surface of the electrophoretic solution, but not affecting the current flow. The conducted study showed that the migration of heated masses of solution is caused by different rates of hydrogen and oxygen production on platinum electrodes. Using technique of real-time thermal imaging, it was demonstrated that in the presence of U-shaped inserts, heating was uniform up to 7°С throughout the entire volume of the solution located above the gel platform. Heating of the liquid in the well area occurred with less dynamics and was not identical. The heating of the liquid in the cathode well occurs insignificantly (only 1.5°C), and at the anode the increase is 2.5°С. We believe that temperature homogeneity will be of significant importance for reducing the variability of the results obtained by the Comet assay (DNA comet) method on preparations subjected to alkaline electrophoresis.
Biofizika. 2025;70(1):137-143
137-143
Markov Network Model for Predicting Thousand Seed Weight in Chickpea Genotypes
Abstract
Predicting yield-related traits such as thousand seed weight (TSW) allows researchers to develop varieties that achieve maximum efficiency and value under changing climate conditions. In this paper, we propose a Markov network model for predicting the important phenotypic trait TSW in chickpea genotypes using pre-selected single nucleotide polymorphisms and weather data for 5 days before and 20 days after sowing, such as minimum and maximum temperatures, precipitation, humidity, infrared radiation, and daylength. The constructed model predicts the TSW trait with high accuracy – the Pearson correlation coefficient is 0.83.
Biofizika. 2025;70(1):144-149
144-149
The 3VmrMLM Method Provides New Genomic Variants Associated with Fiber Characteristics in Flax
Abstract
Flax is an important agricultural crop grown for oil and fiber. Flax fiber is used in various industries, and breeding new flax varieties with better fiber characteristics is subject of interest. Genome-wide association studies (GWAS) can find variants associated with traits important for fiber quality, but differences in data due to different growing conditions in different years reduce the power of GWAS methods. The 3VmrMLM method allows searching for variants in data measured in several environments, allowing finding new variants not found by other methods. Measurements in different years were taken as different environments, and the method found a total of 205 variants characteristic of all or several environments, 37 of which fell into the body of known genes with important functions, the effect of some variants on fiber characteristics was also confirmed in an independent set of plants.
Biofizika. 2025;70(1):150-160
150-160
Global Seismicity as a Marker of Biotropic Environmental Factor
Abstract
A comparison was made of the dynamics of motor activity of hamsters with the number of strong earthquakes with a magnitude of ≥4.5. A positive correlation was found between the total daily physical activity, calculated for the period from 6 p.m. of the previous day through 6 p.m. of the current day, with global seismic activity of the current day (r = 0.34, p = 0.02). Numerous local aftershocks do not affect the biological indicator under study. The data obtained indicate that it is not the consequences of the influence of earthquakes on the geosphere that affect animals, but global seismicity is only a marker of the desired biotropic factor. Moreover, a long-term two-center study (Moscow and Ulyanovsk) established a positive correlation (r = 0.42, p = 0.003) of the intensity of count rate fluctuations from the natural isotope potassium-40 with the level of global seismicity, excluding aftershocks. Taking into account the previously identified connection between fluctuations in the count rate from 40K and biological parameters, this fact indicates the existence of some general influence on animal activity, radioactive decay and global seismicity.
Biofizika. 2025;70(1):167-173
167-173
BearBase: Database of the Museum Collection of Polar Bear Specimens
Abstract
Museum collections of biological specimens are invaluable for research, particularly when paired with modern genetic analysis and omics technology. Although documentation has evolved from paper to digital formats, managing the diverse data requirements of these collections continues to pose challenges. Current software tools are designed for specific tasks and often require advanced technical skills, which can limit accessibility. To tackle these challenges, we developed BearBase, a user-friendly and portable database system that does not necessitate professional expertise. It features both server and client components, supports offline usage, and can sync with mobile devices for fieldwork. Users can easily import data from formats like MS Excel and modify database structure as needed. The open-source code is available on GitHub. Currently, BearBase hosts data on approximately 500 polar bear (Ursus maritimus) specimens from the collection of the Zoological Institute of the Russian Academy of Sciences (St. Petersburg), encompassing those harvested during research and commercial activities dating back to the 19th century. Moreover, the system can be customized to manage other collections of biological or medical specimens.
Biofizika. 2025;70(1):161-166
161-166
Essential Role of Disproportionation Reaction of Nitric Oxide Molecules in Their Functioning Mechanism in Living Organisms
Abstract
The article considers the question of why nitrosyl ligands in dinitrosyl iron complexes with thiol-containing ligands which are proposed as a “working form” of endogenous nitric oxide (NO) in living organisms are presented equally in dinitrosyl iron complexes as NO molecules and nitrosonium (NO+) cations? It has been shown that such type of presentation is determined by the mechanism of dinitrosyl iron complexes formation from NO molecules, loosely bound bivalent iron and thiol-containing compounds in living organisms. The disproprtionation reaction between NO molecules bound in pairs with Fe2+ ion plays the main role in this process. Regarding thiol-containing ligands they ensure the stabilization of nitrosonium cations arising in NO disproprtionation reaction.
Biofizika. 2025;70(1):174-180
174-180
Medical biophysics
Evaluation of the Effectiveness of Trolox, Copper Chlorophyllin and Riboxin when Administered Intraperitoneally to Mice after Acute Irradiation
Abstract
The radioprotective properties of copper chlorophyllin, riboxin (inosine) and trolox (a water-soluble form of vitamin E) were studied after irradiation of outbred male mice of the ICR (CD-1) SPF category with X-ray radiation at a dose of 6.5 Gy. The test substances were administered intraperitoneally to mice an hour after irradiation, then the drugs were administered 3 more times at daily intervals. The volume of administered drugs was 0.32 ml. Dosages for each administration: trolox – 200 μg/g body weight, copper chlorophyllin – 50 or 100 μg/g, riboxin – 200 μg/g. Mice were euthanized 4 days after irradiation. Radioprotective efficacy was assessed based on 30-day survival and on the basis of the following indicators 4 days after irradiation: body weight, weight of the thymus and spleen, hematological indicators (leukocytes, lymphocytes, monocytes, granulocytes, erythrocytes, platelets, hemoglobin, hematocrit, thrombocrit), the number of nucleated cells in the bone marrow, the content of thiobarbiturate-reactive products in the liver. Irradiation caused a decrease in the mass of the thymus and spleen, the content of leukocytes and platelets in the blood, and the number of nucleated cells in the bone marrow. The studied substances, when using the given application scheme, did not contribute to an increase in these parameters. Irradiation led to an increase in the content of thiobarbiturate-reactive products in the liver of mice, which is a marker of lipid peroxidation caused by it. All studied substances contributed to a decrease in this criterion, except for chlorophyllin, administered at a dosage of 100 μg/g (total dosage 400 μg/g). However, only in this case was there an increase in survival compared to the irradiated control group. Trolox and riboxin contributed to a decrease in the content of end products of lipid peroxidation in the majority of mice from the corresponding group. However, in some of them this effect was not observed at all. The use of copper chlorophyllin in the regimen we used led to the appearance of signs of chemical poisoning in mice. We explain this by its manifestation of toxic properties due to the presence of a copper atom in its molecule. It seems promising to repeat the study using a chlorophyll derivative that does not contain copper.
Biofizika. 2025;70(1):181-191
181-191
Biochip Analyzer as an Equipment Component in “Lab-on-Chip” Technology
Abstract
A specially developed wide-field digital microarray analyzer was used for quantitative estimation of weak signals from biochip cells with the fluorescence intensity comparable to that of the substrate material. Luminescence intensity of the different material surfaces that could serve as substrates for biochip matrices used in medical diagnostics was measured in the spectral range of the cyanine dye Cy5 (λex = 645 nm, λem = 665 nm). It was shown that the developed digital microarray analyzer allowed recording the dye Cy5 on a substrate made of black polybutylene terephthalate (black crastin) with concentration of 3 or more molecules/μm2.
Biofizika. 2025;70(1):192-197
192-197
Biophysical Basics of the Use of Isometric Exercises in the Rehabilitation of Patients after Hip Replacements
Abstract
Currently, isometric exercises are widely used to increase muscle strength and endurance. Isometric exercises are used also in rehabilitation protocols for limited joint mobility after arthroplasty operations. The article reviews the effect of isometric exercises on the morphofunctional characteristics of muscle cells, cytokine secretion by muscle cells, blood circulation and mass transfer in muscle tissue, as well as on bone remodeling and repair. The existing protocols for early rehabilitation of patients after total hip replacement are not optimal; they do not take into account the individual characteristics of patients. To develop effective methods of early rehabilitation of patients after hip replacement, it is necessary to understand the biophysical basis of the effect of isometric exercises on the processes of regeneration of muscle and bone tissues.
Biofizika. 2025;70(1):198-208
198-208