Background: The search for an effective therapy for local radiation injuries (LRI) is urgent; one option is mesenchymal stem cells (MSC) derived from the placenta and their conditioned medium for the regenerative processes of the skin. Methods: We used 80 animals, randomly assigned to four groups: control (C) animals that did not receive therapy; control with the introduction of culture medium concentrate (CM); introduction of MSCs (PL); introduction of CMPL. LRI modeling was performed on an X-ray machine at a dose of 110 Gy. Histological and immunohistochemical tests were performed. Results: On the 112th day, the area of the open wound surface in the CMPL group was 6.7 times less than in the control group. Complete healing of the open wound surface of the skin in the CM group was observed in 40%, in CMPL 60%, in the PL group 20%, and in the C group there were no animals with a prolonged wound defect. A decrease in inflammatory processes was observed in the CMPL group. Conclusions: the use of a concentrate of conditioned MSCs (CMPL group) in severe LRI in laboratory animals accelerates the transition of the wound process to the stage of regeneration and epithelization.

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.

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: 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.

Introduction. The use of autologous stromal-vascular cell fraction of adipose tissue seems to be one of the promising technologies to increase the effectiveness of skin grafting and other skin restoration options in burnt patients. The main regenerative component of the stromal-vascular fraction are mesenchymal stem cells, which have a high reparative potential and low immunogenicity.The aim of the study was to increase the effectiveness of surgical treatment of patients with skin burns through the injection of autological stromal-vascular cell fraction of the adipose tissue.Materials and methods. The study was conducted as part of a prospective, open, randomized study involving 61 patients with extensive skin burns treated in burn centers Dzhanelidze Saint-Petersburg Research Institute of Emergency Medicine and Vishnevsky National Medical Research Center of Surgery, Ministry of Health of Russia, in 2021-2023. Cells of the stromal-vascular fraction of the adipose tissue were obtained mechanically and enzymatically. The prepared cell suspension was introduced into the granulation tissue during skin grafting with split autodermal grafts having a high perforation coefficient. During the study, planimetric parameters, as well as the results of histological and immunohistochemical tests, were assessed. The obtained findings were processed using generally accepted algorithms of variation and descriptive statistics. The alternative hypothesis was accepted at p0.05.Results. The proposed technique of autologous stromal-vascular cell fraction of the adipose tissue with simultaneous autodermoplasty with a split perforated graft allowed reducing the time of perforating cell epithelization by 28% (p0.05), the time of final engraftment by 11% (p0.05), the frequency of infectious complications in the postoperative period by 20% (p0.05), as well as the frequency of lysis and rejection reactions by 15% (p0.05). As stated, the introduction of an autologous stromal-vascular fraction during skin grafting resulted in early relief of the inflammatory reaction in the area of a deep burn wound, the fact being supported by clinical, cytological, histological and immunohistochemical tests.Conclusion. The use of cells from the stromal-vascular fraction of the adipose tissue can significantly increase the effectiveness of surgical treatment of patients with extensive skin burns. The proposed technique to obtain and apply the stromal-vascular fraction of the adipose tissue at the stage of autodermoplasty can be introduced into clinical practice in both burn centers and surgical/trauma departments, since it does not require special equipment.

Neuroplasticity and inflammation play important part in the body’s adaptive reactions in response to prolonged physical activity. These processes are associated with the cross-interaction of the nervous and immune systems, which is realized through the transmission of signals from neurotransmitters and cytokines. Using the methods of flow cytometry and advanced biochemical analysis of blood humoral parameters, we showed that intense and prolonged physical activity at the anaerobic threshold, without nutritional and metabolic support, contributes to the development of exercise-induced immunosuppression in sportsmen. These athletes illustrate the following signs of a decreased immune status: fewer absolute indicators of the content of leukocytes, lowered values in the immunoregulatory index (CD4⁺/CD8⁺), and diminished indicators of humoral immunity (immunoglobulins A, M, and G, and IFN-γ). These factors characterize the functional state of cellular and humoral immunity and their reduction affects the prenosological risk criteria, indicative of the athletes’ susceptibility to develop exercise-induced immunosuppression.