Cell therapy is a promising direction in medicine, which can significantly improve the results of treatment of various diseases, including local radiation injuries (LRI). The purpose of the study was to compare the results of using decellularized human amniotic membrane isolated and together with lyophilisates of conditioned media of MSCs from the human gingival mucosa and MSCs from human placental tissue and their effect on tissue regeneration in LRI. Material and methods: The study included 42 laboratory animals (white male rats of the Wistar line), randomly divided into 6 groups: K – control group without therapy, on the 21st day after irradiation, groups using: Am+LD – application of lyophilisate of the conditioned medium of MSCs of the human gingival mucosa (LD) under the decellularized amniotic membrane, Am+LP – application of lyophilisate of the conditioned medium of MSCs of human placental tissue (LP) under the decellularized amniotic membrane, Am – application of the decellularized amniotic membrane, AmCl – application of the decellularized amniotic membrane with medical glue BF-6, Kl – application medical glue BF-6. Modeling of LRI in animals was carried out on an LNK-268 X-ray unit at a dose of 110 Gy and observed until the 112th day after irradiation, monitoring of the ulcerative surface of the skin and the course of the inflammatory process of LRI was carried out with calculation of the area of ​​the total changed skin in the ImageTool software. Planimetric and histological analyzes were performed. Results: It was demonstrated that, when compared with the control, the use of decellularized amniotic membrane in LRI on days 77 and 112 after irradiation increased the healing rate by 4.6 and 18 times, respectively; decellularized amniotic membrane with lyophilisate of placental MSC conditioned medium increased the rate of wound healing by 13.5 and 27 times, respectively; and a dellularized amniotic membrane with lyophilisate of MSCs from the human gingival mucosa to 100 % healing. Healing of the ulcer surface area of the LRI in 83.5 % of animals in the Am group demonstrated the effectiveness of using isolated decellularized amniotic membrane even in the absence of human MSC lyophilisates. At the same time, healing of the ulcer surface area of the LRI in the AmCl group was 20 % of cases, where the decellularized amniotic membrane was fixed with BF-6 medical glue, which was less effective compared to other groups. Conclusion: The proposed combined use of decellularized amniotic membrane with lyophilisates of the conditioned medium of mesenchymal stromal cells (MSCs) of the placenta and mucous tissue of the human gums and the isolated use of decellularized amniotic membrane led to complete epithelization of the ulcer surface, a pronounced favorable course of grade IIIb–IV LRI in laboratory animals and a reduction in healing time , the absence of local or systemic complications can be considered as a promising method of conservative treatment for LRI of the skin and a new therapeutic approach in the treatment of non-healing and chronic wounds.

Despite modern advances in surgery, the problem of pathological scarring is still remains relevant. It can lead to both serious dysfunctions of various organ systems and cosmetic defects, which significantly reduces the quality of patients’ life. In search of effective methods for the prevention of scarring, we paid attention to the amniotic sac, which, due to its properties, is able to provide tissue protection and prevent scar-adhesive processes. We have illustrated the positive results of the amnion usage in surgery of sciatic nerve neurotization in rabbits; a safety and effectiveness of this method have been also presented. The amniotic sac is a promising biomaterial for the prevention of pathological scarring and improvement of postoperative outcomes. However, further research and standardization of production are needed for its widespread use.

Background: Tracking the migration pathways of living cells after their introduction into a patient’s body is a topical issue in the field of cell therapy. Questions related to studying the possibility of long-term intravital biodistribution of mesenchymal stromal cells in the body currently remain open. Methods: Forty-nine laboratory animals were used in the study. Modeling of local radiation injuries was carried out, and the dynamics of the distribution of mesenchymal stromal cells labeled with [89Zr]Zr-oxine in the rat body were studied. Results: the obtained results of the labelled cell distribution allow us to assume that this procedure could be useful for visualization of local radiation injury using positron emission tomography. However, further research is needed to confirm this assumption. Conclusions: intravenous injection leads to the initial accumulation of cells in the lungs and their subsequent redistribution to the liver, spleen, and kidneys. When locally injected into tissues, mesenchymal stromal cells are not distributed systemically in significant quantities.

This article describes the process of developing a tissue-engineered structure that meets the biocompatibility and biodegradation parameters necessary for replacing cartilage tissue defects. The study was carried out using 3D bioprinting technology, which represents a promising research direction in the biomedical field. It is known that, due to the specifics of its structure, cartilage tissue is not capable of complete regeneration of damage. The methods currently used for treating arthrosis are associated with a number of limitations and disadvantages, which makes research aimed at developing alternative methods for arthrosis treatment particularly relevant. The development of tissue-engineered structures by 3D bioprinting requires the materials not only certified for medical use but also exhibiting biocompatibility and biodegradation properties. Polylactide (PLA) and sodium alginate satisfy the above requirements; moreover, their availability and economic affordability make them one of the most popular materials for 3D bioprinting.

Purpose: To evaluate the frequency and spectrum of chromosome aberrations under X-Ray exposure at doses of 80, 250, and 1000 mGy in a human multipotent mesenchymal stromal cell (MMSC) cell line during long-term cultivation. Material and methods: MMSCs were isolated from human gingival mucosa by an enzymatic method and cultured in a serum-free medium. The presence of surface antigens was determined using the method of flow cytometry. The ability of the cell line to differentiate in the osteogenic, adipogenic, and chondrogenic directions was studied using induction media. Authentication was performed by genotyping of polymorphic STR loci, cytogenetic analysis was performed by multicolor fluorescent in situ hybridization (mFISH). Irradiation was carried out on an X-ray biological unit RUB RUST-M1 (Russia) at a dose rate of 40 mGy/min, a voltage of 100 kV, and a current of 0.8 mA. Results: At the first passage after irradiation, a statistically significant increase in the frequency of non-clonal CA compared with the control was recorded at a dose of 80, but not 250 and 1000 mGy. At the late stages of cultivation, the average frequency of breaks per chromosome in the group of non-irradiated cells did not differ from the values obtained after irradiation at doses of 80, 250, and 1000 mGy (p > 0.05). However, in MMSCs irradiated at a dose of 80 mGy, damage occurred more often in pairs of chromosomes 6 and 10, and at a dose of 1000 mGy, in a pair of chromosomes 9. A single irradiation of MMSCs in vitro did not affect the growth and progression of MMSCs characteristic of the studied primary cell line, of clonal cells with chromosome translocations and monosomy X, but led to an increase in the representation of a clone with tetrasomy 8. The total number of random clones with chromosome translocations that arose de novo increased after irradiation at a dose of 1000 mGy. Conclusion: Minor fluctuations in the proportion of cells with non-clonal CA, depending on the dose received in the early stages after irradiation (passage 1–4), disappeared at the later stages of cultivation (passage 8–14). There were no differences in mean frequencies between irradiated and non-irradiated MMSCs, but after irradiation, damage to some chromosomes could occur more frequently than others. A single X-ray irradiation of MMSCs can promote the growth and progression of primary pathological cytogenetic clones, regardless of the dose received, as well as an increase in the total number of de novo cell clones with chromosomal translocations that have arisen. A single X-ray irradiation of MMSCs can promote the growth and progression of primary pathological cytogenetic clones, regardless of the dose received, as well as an increase in the total number of de novo cell clones with chromosomal translocations that have arisen.

Background: Adjuvant radiation therapy (ART), an integral part of locoregional breast cance (BC) therapy, acting not only locally, but also systemically and leads to a shift in homeostasis, which is reflected in routine general clinical tests. Tumor necrosis factor (TNF) is a proinflammatory cytokine, the production of which can be influenced by the single-nucleotide substitution -308(G/A)TNF. The minor allele -308A can be included in the stable inherited haplotype AH8.1 of the HLA gene complex. At the same time, the carriage of the -308A without the AH8.1 haplotype is associated with a poor prognosis in patients with BC. The aim of the study was to evaluate the features of the systemic response to the course of ART in carriers of TNF-associated genotypes with BC. Material and methods: The sample is represented by 147 BC patients who underwent a course of ART (2 Gy in 25 fractions). Clinical and morphological characteristics and data of general clinical blood analysis were obtained from medical histories. Venous blood samples for the study were obtained at the beginning and at the end of the ART course. Alleles -308(G/A)TNF and marker alleles of haplotype AH8.1 (HLA-A×01, HLA-B×08 and HLA-DRB1×03) were determined by allele-specific PCR. sTNF concentrations were determined by the ELISA in 102 blood plasma samples. Results: TNF-associated comparison groups were identified based on genotyping: (1) 114 carriers -308GG of the TNF gene, regardless of the AH8.1 haplotype (77,6 %); (2) 23 carrier -308A(AH8.1pos) had at least one AH8.1 marker allele (15.6 %); (3) 10 carriers -308A(AH8.1neg) did not have any AH8.1 marker allele (6.8 %). In the -308A(AH8.1neg) group the average concentration of sTNF both at the beginning and at the end of ART was significantly higher and, unlike other comparison groups, did not significantly decrease at the end of the ART course. A significant decrease in absolute values was revealed during ART in a number of cases for leukocytes, platelets and lymphocytes, however within the reference values. In the group -308A(AH8.1neg) correlation analysis revealed a high strength of positive connections between sTNF and leukocytes (r=0.71; p=0.027), platelets (r=0.67; p=0.04), neutrophils (r=0.70; p=0.027) only at the end of ART, whereas at the beginning ART these correlations were weak (r≤0.3) and statistically unreliable. For other genetic groups, the revealed correlations were not strong enough. Conclusion: The revealed features of the systemic response to ART for carriers of a prognostically unfavorable genotype -308A(AH8.1neg) – a high concentration of sTNF and a positive correlation with the content of leukocytes (probably due to neutrophils) and platelets – can be considered as targets of individualized therapy.

Each person is inevitably exposed to low doses of ionizing radiation (LDIR) throughout their life. The research results of LDIR effects are ambiguous and an accurate assessment of the risks associated with the influence of LDIR is an important task. Mesenchymal stromal cells (MSCs) are the regenerative reserve of an adult organism; because of this, they are a promising model for studying the effects of LDIR. The qualitative and quantitative changes in their characteristics can also be considered promising criteria for assessing the risks of LDIR exposure. The MSCs from human connective gingiva tissue (hG-MSCs) were irradiated at doses of 50, 100, 250, and 1000 mGy by the X-ray unit RUST-M1 (Russia). The cells were cultured continuously for 64 days after irradiation. During the study, we evaluated the secretory profile of hG-MSCs (IL-10, IDO, IL-6, IL-8, VEGF-A) using an ELISA test, the immunophenotype (CD45, CD34, CD90, CD105, CD73, HLA-DR, CD44) using flow cytometry, and the proliferative activity using the xCelligence RTCA cell analyzer at the chosen time points. The results of study have indicated the development of stimulating effects in the early stages of cultivation after irradiation using low doses of X-ray radiation. On the contrary, the effects of the low doses were comparable with the effects of medium doses of X-ray radiation in the long-term periods of cultivation after irradiation and have indicated the inhibition of the functional activity of MSCs.

Background: Radiation therapy (RT) is an important step in the treatment of primary breast cancer as it is one of the leading contributors to cancer incidence among women. Most patients with this disease acquire radiation-induced lymphopenia in the early post-radiation period; however, little is known about the effect of RT on the composition of lymphocyte populations in such patients. This study was aimed at investigating the effect of adjuvant remote RT—performed in the classical mode for patients with primary breast cancer—on the main components of cell-mediated immunity (major lymphocyte populations), including those in patients receiving chemotherapy. Methods: Between 2020 and 2022, 96 patients with stage I–III breast cancer were included in this study. All patients in the final stage of complex treatment received RT via a 3D conformal technique (3DCRT). The clinical target volume of this RT included the breast or chest wall and locoregional lymphatics. Flow cytometry was used to assess the levels and phenotypes of circulating lymphocytes before and after RT (no more than 7 days before and after RT). The evaluation of the impact of polychemotherapy (PCT) was conducted to determine whether it was a risk factor for the onset of radio-induced lymphopenia (RIL) in the context of RT. Results: When assessing the immune status in the general group of patients (n = 96), before the start of adjuvant external beam radiotherapy (EBRT), the average number of lymphocytes was 1.68 ± 0.064 × 109/L; after the course of adjuvant EBRT, it decreased to 1.01 ± 0.044 × 109/L (p < 0.001). When assessing the absolute indicators of cellular immunity in the general group of patients with BC after a course of adjuvant EBRT, significant dynamics were revealed by the changes in all cell populations of lymphocytes (paired t-test, p < 0.05). Conclusion: The adaptive immune system in breast cancer patients changed in the early post-radiation period. The absolute levels of B-, T- and natural killer cells significantly reduced after RT regardless of whether the patients previously underwent chemotherapy courses. RT for patients with primary breast cancer should be considered in clinical management because it significantly alters lymphocyte levels and should be considered when assessing antitumor immunity, as significant changes in T-cell immunity have been observed. In addition, the identified changes are critical if specific targeted therapy or immunotherapy is needed.

Purpose: To evaluate the influence of a humic-fulvic acid substance on the quantitative yield of residual foci of the DNA double-strand break (DSB) repair protein-marker - phosphorylated histone H2AX (γH2AX) and proliferation activity in a culture of human mesenchymal stromal cells (MSCs) 24, 48, and 72 h after exposure to X-ray radiation at doses of 2, 4 and 10 Gy. Material and methods: Through 24 hours after incubation of MSCs with a substance of humic-fulvic acids (Humic Complex, OOO Sistema-BioTechnologies, Russia) at a dilution of 1/1000. Cells were irradiated on an X-ray biological device RUB RUST-M1 at a voltage of 200 kV, beam current 2×5 mA, aluminum filter 1.5 mm, absorbed dose rate 0.85 Gy/min. Immunocytochemical staining was used to quantify the residual γH2AX foci and the percentage of proliferating cells using antibodies to γH2AX and Ki-67 (a marker protein for cell proliferation), respectively. Statistical analysis of the obtained data was carried out using the statistical software package Statistica 8.0 (StatSoft). To assess the significance of differences between samples, Student’s t-test was used. Results and conclusion: The conducted studies showed that on the cell model used and under the above experimental conditions, the humic-fulvic acid substance does not affect the efficiency of repair of radiation-induced DNA DSBs, however, it significantly reduces the proliferation activity of both irradiated and non-irradiated MSCs. It is advisable to conduct detailed studies of the molecular and cellular mechanisms of the antiproliferative effect of humic and fulvic acids.

Tumor necrosis factor (TNF) plays an important role in the pathogenesis of breast cancer (BC). The -308(G/A)TNF polymorphism allele -308A is part of the autoimmune ancestral haplotype AH8.1 associated with elevated serum sTNF levels. Previously, we showed a decrease in overall survival for carriers -308A/AH8.1-. The aim of the study was to assess the effect of haplotypes AH8.1 on the level of sTNF and clinical and morphological characteristics of BC patients. The study included 100 people with adjuvant radiotherapy treatment. The concentration of sTNF was determined by the ELISA. Additionally, 30 archival DNA samples of primary BC patients carrying the allele -308A with a known sTNF level were genotyped. Alleles -308(G/A)TNF and marker alleles of haplotype AH8.1 (HLA-A*01, HLA-B*08 and HLA-DRB1*03) were determined by allele-specific PCR. Based on the polymorphism of -308(G/A)TNF and marker alleles of haplotype AH8.1, three comparison groups were identified: -308GG carriers of the TNF gene independently of haplotype AH8.1 (76

Purpose of the study. The aim of this work was to study the effect of conservation in various cryoprotectants on the biomechanical and morphological properties of the umbilical cord (UCA) arteries.Materials and methods. The material for this work was 12 umbilical arteries, which were divided into 4 study groups: (1) native UCA – control without freezing; (2) APC frozen in 5 % dextran with the addition of dimethyl sulfoxide (DMSO) to 10 % and 7.5 % human serum albumin (HSA); (3) APC frozen in glycerin and (4) UCA frozen in propanediol. For all groups, morphological and biomechanical studies were carried out. The statistical data were processed using the GraphPad Prism 9.2.0 program. Analysis of variance was used to find significant differences.Results. Freezing with 5 % dextran, 10 % DMSO and 7.5 % human albumin did not lead to significant changes in the morphology of vascular tissue compared to control. The conserved vascular tissue retains a moderate level of type I collagen, regardless of the method of conservation. The presence of statistically significant differences between the control and frozen UCAs was shown for Young's modulus (p < 0.05; 6.9 [6.8; 7.0] for the native artery; 2.3 [2.0; 2.6] for the artery preserved with the use of dextran, DMSO and human albumin; 2.3 [1.4; 3.2] for the artery preserved in glycerin and 0.8 [0.6; 1.0] – in propanediol, respectively).Conclusion. 1) Freezing and storage of UCA at 5 % dextran, 10 % DMSO and 7.5 % HSA does not lead to a significant change in the morphology of vascular membranes and cell nuclei; 2) The preservation of type I collagen according to the results of IHC is qualitatively reduced from a conditional indicator of +2 to +1 for frozen agroindustrial complexes compared with control ones; 3) Conservation leads to a significant decrease in the modulus of elasticity of the walls of the agroindustrial complex compared with control vessels (p < 0.05).

Purpose: Study of chromosomal aberration yields with a three-color FISH method in the peripheral blood lymphocyte cultures of patients with breast cancer before and after local irradiation. Material and methods: Venous blood was obtained from 24 patients aged from 33 to 79 years which suffering from cancer of the left or right breast after the implementation of a sectoral or radical resection of an affected organ with subsequent local adjuvant distant radiation therapy (DRT) to the scar area. Also it could be preceded by adjuvant polychimotherapy (PCT). A linear accelerator of the Trilogy system based on the Clinac iX platform was used for local irradiation. SOD was installed at 50 Gy per 25 fractions (daily 2 Gy). venous blood sampling produced to PCT and/or DRT and after 1 and/or 3 months after irradiation. A set of DNA probes to 1, 4 and 12 pairs of chromosomes was used for three-color FISH staining. Results: Levels of translocations, dicentrics and acentrics (per 100 cells) in peripheral blood lymphocyte cultures of patients up to DRT did not differ significantly with and without PCT and were amounted to average 0.63 ± 0.10; 0.10 ± 0.04 and 0.17 ± 0.06, respectively. The frequency of these chromosome rearrangements significantly increased after radiation therapy by an average of up to 4.62 ± 0.46; 1.48 ± 0.19 and 0.95 ± 0.14. The differences between 1 and 3 months of taking material after irradiation were absent. One of the patients, unlike the rest, was cytogenetically examined 11 years after a similar local irradiation, and the frequencies of translocations and dicentrics in her lymphocyte culture were 4.56 and 0.19 (per 100 cells), respectively, while they were varied from 1.63 to 10.00 for translocations and from 0.27 (0 in one patient) to 4.06 for dicentrics for other patients. Conclusion: When using a three-color FISH method there was a significant increase in the frequencies of translocations, dicentrics and acentrics in peripheral blood lymphocyte cultures of patients after DRT of breast cancer. At the same time there were more translocations than dicentrics and, apparently, they remain at the initial level for a long time. The frequency of translocations per 1 cell with translocations in the peripheral blood lymphocyte cultures in most cases exceeds 1 after local DRT of the breast cancer. The correlation between average physical doses to the whole body and cytogenetical estimates in individual patients was statistically insignificant.

Purpose: Evaluation of the effectiveness of the use of human decellularized amniotic membrane, both as an independent covering material and as a cell-free matrix for syngeneic regenerative cells of adipose tissue (stromal-vascular fraction – SVF, adipose tissue ‒ AT) in local radiation injuries (LRI) IIIb-IV severity in laboratory animals. Material and methods: 42 laboratory animals were studied. LRI modeling was carried out on an X-ray at a dose of 110 Gy. Animals were randomized randomly and divided into 6 groups depending on the type of treatment: 1st group (K) ‒ control group animals after irradiation did not receive specific treatment; the 2nd group (Gl) ‒ after irradiation, medical glue BF-6 was applied to the ulcer surface on the 21st day; 3rd group (Am) ‒ animals after irradiation on the ulcer surface was applied decellularized amniotic membrane, fixed with interrupted sutures on the 21st day; 4th group (Am-Gl) ‒ animals after irradiation on the ulcer surface was applied decellularized amniotic membrane, fixed with medical adhesive BF-6 for 21 days; 5th group (SVF-Gl) ‒ after irradiation, the SVF AT at a dose of 0.4×106 cells was applied to the ulcer surface after irradiation, followed by fixation with BF-6 medical glue for 21 days; the 6th group (Am-SVF) ‒ after irradiation, SVF AT was applied to the ulcer surface at a dose of 0.4×106 cells under the decellularized amniotic membrane, fixed with interrupted sutures on the 21st day. Results: On the 112th day, complete healing of the ulcer was observed in 100 % of animals in the Am-Gl group, in 70 % in the Am and Gl groups. There was no complete healing of the ulcer in the SVF-CGl and Am-SVF groups. The greatest reduction in the area of the total altered skin from 21 to 112 days of the experiment was noted in the groups Gl-SVF (34.7 %), K (31.6 %), Am-SVF (30.7 %). In the Am-Gl and Am groups, a reduction in the area of the total altered skin was recorded by 24.6 % and 14.7 %, respectively. In the GL group, the reduction in the area of the total altered skin was the smallest, by only 13.5 %. Conclusion: The use of a decellularized human amniotic membrane fixed with medical adhesive BF-6 can be considered as a promising method for the conservative treatment of LRI of the skin.

Throughout life a person is inevitably exposed to low doses of ionizing radiation (LDIR) both background radiation and as part of medical treatment and diagnostics, during professional activities, air travel etc. Today the effects of LDIR and the risks of long-term consequences of this impact are increasingly attracting the researchers attention. On the one hand, scientists point to the development of negative consequences, in particular, the accumulation of double-stranded breaks DNA, on the other hand, some studies demonstrating the development of such events as hormesis and adaptive response. Based on this, there is an assumption that in the range of LDIR may exist a non-linear dependence of the effects on the radiation dose, i.e. the effect isn’t proportional to the received dose and that is consistent with the threshold-concept. Today many scientific papers are devoted to this area of research. Special attention is drawn to the effects LDIR on human mesenchymal stromal cells (MSCs) because they are the regenerative reserve of the body. Due to the them ability to self-sustain MSCs can stay in the body for a long time and undergo several rounds of irradiation, accumulating the changes in themselves and passing ones to the next generations of cells since they have the potential to the differentiation. Thus, changes that have occurred in the MSCs affect the human body as a whole. Based on all of the above, it can be concluded that the study of the effects of LDIR on mesenchymal stromal cells of human is actual area of research currently.

Objective. Isolation of stem cells (SCs) from different parts of the placenta and description of their biological characteristics. Materials and methods. The placenta was obtained from parturient women aged 22 to 39 years (mean age was 29.0 ± 3.7 years) with a normal singleton pregnancy resulting in normal delivery and with written informed consent obtained at 37–41 weeks of gestation after non-invasive (n = 32) or operative (n = 2) delivery. Wharton’s jelly from the umbilical cord and the fetal side of the placenta, the chorionic plate with chorion frondosum, were isolated and cultured to obtain mesenchymal stem cells (MSCs). Morphological evaluation of cell culture, differentiation, immunological characterization (CD34, CD45, CD90, CD105, CD73, HLA-DR (BD Biosciences and Becman Coulter, USA)), assessment of viability using 7-ADD dye on the FACSCanto II flow cytometry facility (Becton Dickinson CA, USA), cell growth, sterility control, analysis of STR (Short tandem repeat) loci polymorphism for identification, karyotyping, and cryopreservation of cell cultures were carried out. Results. Primary cell cultures were isolated from the chorionic plate with chorion frondosum and Wharton’s jelly of the umbilical cord in 100% of cases. MSCs had high proliferative activity and viability (98.0 ± 1.2% 7-ADD) throughout the whole period of cultivation. The growth rate of MSCs from the chorionic plate at P3, P4, and P5 was higher compared to that of MSCs from the Wharton’s jelly during cultivation, p ≤ 0.05. Immunophenotype corresponded to the requirements of International Society for Cellular Therapy: high expression of MSC markers (CD73, CD90, CD105) was detected; hematopoietic and lymphocytic markers were absent (CD34, CD45, HLA-DR). The potential of cells to differentiate in the mesenchymal direction (chondrocytes, osteocytes, adipocytes) was confirmed in all obtained MSCs. In 95% of cases, the cells were of fetal origin. The karyotype of the examined MSC cell lines was normal: 46, XX (female) or 46, XY (male). All cell cultures were tested, cryopreserved, and placed in a biobank. Conclusion. Isolation and evaluation of biological characteristics of human placental stem cells is of great interest and is a promising direction in regenerative medicine due to the simplicity of placenta sampling, the absence of ethical problems, the ability to quickly obtain and accumulate the necessary amount of cell material with a stable genotype and given biological characteristics. Key words: mesenchymal stem cells, placenta, immunophenotype, STR loci polymorphisms, karyotype

Purpose: To study the effect of radiation sterilization at an ultra-high dose of 30 kGy on the cytocompatibility of decellularized vascular scaffolds repopulated with placenta MSCs. Materials and methods: The material of the study were aortas of laboratory animals (rabbits and rats, three vessels for each animal species), which were subjected to detergent - enzymatic perfusion decellularization by two protocols differing in reagents composition. Then the scaffold decellularized by the most efficient protocol was irradiated at a dose of 30 kGy and repopulated with placenta MSCs. As a control, the unirradiated matrix was seeded with cells of the same type. Histological staining of hematoxilin – eosin, IHC for type I collagen and Ki67, DAPI staining and quantitative assessment of genomic DNA were used to evaluate the effectiveness of decellularization and seeding. Scaffolds seeding was assessed by analyzing serial sections taken on day 1st, 3rd, and 4th of culture. Results: The scaffolds obtained in accordance with Protocol 1 were characterized by the absence of detectable cell nuclei, while the DNA content in them was significantly lower compared to Protocol 2. On the digitized images of sections of the unirradiated matrix, the cell nuclei were determined for routine H&E and DAPI staining while for the irradiated scaffold the cell nuclei were visualized on the border between the scaffold and fibrin gel only on DAPI stained section at 1st day of culture. The frequency of occurrence of Ki67+ nuclei on the 4th day of culture was significantly lower for the irradiated scaffold in comparison with the non-irradiated scaffold (7.5% and 29.8%, respectively, p=0.0054). Conclusion: Scaffold irradiation leads to loss of cytocompatibility of tissue-engineering constructs.

. It has been noted that one of the most common types of radiation injuries when a person is exposed to ionizing radiation is radiation burns — severe local radiation injuries. The aim of the study i s to apply stromal and vascular fraction of adipose tissue to increase the efficiency of complex therapy for lo- cal radiation lesions. Materials and methods of the study. In 2017-2019, 7 patients (all male; mean age — (54.83±9.41) years) with local radiation le- sions of the skin — ulcerative-necrotic lesions of the skin and underlying tissues — were treated at the Federal Medical Biophysical Center named after A.I. Burnazyan of FMBA of Russia. For more than 6 months the patients received conventional conservative ther- apy of local radiation lesions and a single injection of cell suspension of autologous cells of stromal-vascular fraction of adipose tissue — the average number of cells was (60.33 × 106±64.04). Results of the study and their analysis. All patients had no serious adverse events and reactions associated with the introduction of autologous regenerative cells of adipose tissue. During the whole period of observation after stromal-vascular fraction of adipose tissue was injected, late radiation ulcers remained without signs of inflammation and infiltration. The patients were discharged from the hospital in satisfactory condition. According to the authors, the use of stromal-vascular fraction of adipose tissue in local radiation lesions provides favorable conditions: to increase the effectiveness of complex therapy; to reduce healing time of the wound surface; to regulate and activate im- mune and reparative processes in the dermis; to restore the damaged vascular network, lost skin without severe scarring changes; to heal and achieve a satisfactory result, decent quality of life of patients.