The current treatment of radiation-induced skin wounds utilizes mainly conventional therapies, including topical steroids, creams, ointments, and hydrogel dressings, which do not take into account the immunologic changes that occur in the skin after radiation exposure. Therefore, it is relevant to consider alternative therapies and their impact on changes in the immune landscape of the skin. The aim of this study was to investigate the effect of allogeneic minimally manipulated keratinocytes and fibroblasts on rat skin repair and the development of immune responses. We found that the use of cell therapy compared to treatment with syntazone ointment and no treatment resulted in faster healing and a reduction in the size of radiation-induced skin wounds, area of inflammation, and edema. Additionally, in the group receiving the cell therapy application, there was an observed increase in the number of mast cells (MCs), activation of MC interaction with M2 macrophages, a reduction in the direct contact of MCs with the vascular bed, an increase in the content of collagen fibers due to the intensification of collagen fibrillogenesis, and a restoration of their histotopographic organization. Thus, the positive effect of cell therapy based on allogeneic minimally manipulated keratinocytes and fibroblasts on skin regeneration indicated that it can be used in clinical practice to improve the effectiveness of rehabilitation after radiation therapy.

Objective: Traditional cell-based radiobiological methods are inadequate for assessing the toxicity of ionizing radiation exposure in relation to the microstructure of the extracellular matrix. Organotypic tissue slices preserve the spatial organization observed in vivo, making the tissue easily accessible for visualization and staining. This study aims to explore the use of fluorescence microscopy of physiologically compatible 3D tissue cultures to assess the effects of ionizing radiation. Methods: Organotypic tissue slices were obtained by vibratome, and their mechanical properties were studied. Slices were exposed by two ionizing radiation sources; electron beams (80 Gy and 4 Gy), and soft gamma irradiation (80 Gy and 4 Gy). Two tissue culture protocols were used: the standard (37°C), and hypothermic (30°C) conditions. A qualitative analysis of cell viability in organotypic tissue slices was performed using fluorescent dyes and standard laser confocal microscopy. Results: Biological dosimetry is represented by differentially stained 200-µm thick organotypic tissue sections related to living and dead cells and cell metabolic activity Conclusion: Our results underscore the ability of fluorescence laser scanning confocal microscopy to rapidly assess the radiobiological effects of ionizing radiation in vitro on 3D organotypic tissue slices.

Chimeric antigen receptor (CAR)-T cell therapy yields good results in the treatment of various hematologic malignancies. However, the efficacy of CAR-T cell therapy against solid tumors has proven to be limited, primarily because the tumor-associated extracellular matrix (ECM) creates an intractable barrier for the cytotoxic CAR-T cells that are supposed to kill cancer cells. This review unravels the multifaceted role of the tumor-associated ECM in impeding CAR-T cell infiltration, survival, and functions within solid tumors. We analyze the situations when intratumoral ECM limits the efficacy of CAR-T cell therapy by being a purely physical barrier that complicates lymphocyte penetration/migration and also acts as an immunosuppressive factor that impairs the antitumor activities of CAR-T cells. In addition, we highlight promising approaches such as engineering CAR-T cells with improved capabilities to penetrate and migrate into/through the intratumoral ECM, combination therapies aimed at attenuating the high density and immunosuppressive potential of the intratumoral ECM, and others that enable overcoming ECM-related obstacles. A detailed overview of the data of relevant studies not only helps to better understand the interactions between CAR-T cells and the intratumoral ECM but also outlines potential ways to more effectively use CAR-T cell therapy against solid tumors.

Abstract Background Due to non-vascularized and aneural structure, articular cartilage has limited self-repairing capacity. The aim of this study was to investigate the revitalization of inflammatory injured articular cartilage matrices by human nasal chondrocytes (hNC). Materials and methods Cartilage matrix was prepared by devitalization of articular cartilage samples obtained intraoperatively from an adult patient undergoing knee joint replacement. hNC were obtained from native tissues by enzymatic digestion with further expansion over two passages. The obtained nasal chondrocytes were used to seed decellularized scaffolds, which were then cultured in vitro for 7, 14, or 21 days in chondrogenic medium. Migration was observed by histologic staining with fast green, safranin-O, and hematoxylin and scanning electron microscopy. Biochemical analysis was performed to determine the glycosaminoglycan (GAG) and DNA content of the cartilage using dimethylmethylene blue and CyQuant Cell Proliferation Assay Kit. Results We seeded healthy and inflamed cartilage with nasal chondrocytes and found that the cells actively invade mainly pathologically altered cartilage. The results of biochemical quantitative analysis showed that the amount of DNA significantly increased by day 7 and decreased by day 14, while the quantitative values of GAGs had the opposite trend. Histological staining showed that cartilage formation occurred on day 7, intercellular spaces were filled with de novo synthesized cartilage matrix with significantly low GAG content on day 14, and newly formed GAG-rich cartilage was observed on day 21. The obtained data on cartilage regeneration were confirmed by scanning electron microscopy. Conclusions Our preliminary results showed that human nasal chondrocytes are capable of infiltrating the pathologically altered extracellular matrix of articular cartilage damaged by arthritis, thereby promoting its repair to a physiologically relevant state. Graphical Abstract

Bilio-biliary anastomosis (BBA) is a critical surgical procedure that is performed with the objective of restoring bile duct continuity. This procedure is often required in cases where there has been an injury to the extrahepatic bile ducts or during liver transplantation. Despite advances in surgical techniques, the healing of BBA remains a significant challenge, with complications such as stricture formation and leakage affecting patient outcomes. The stromal vascular fraction (SVF), a heterogeneous cell population derived from adipose tissue, has demonstrated promise in regenerative medicine due to its rich content of stem cells, endothelial progenitor cells, and growth factors. The objective of this study was to evaluate the potential of locally administered autologous SVF to enhance the healing of BBAs. Bilio-biliary anastomosis was performed on a swine model (female Landrace pigs). Six swine were divided into two groups: the treatment group (n = 3) received a local application of autologous SVF around the anastomosis site immediately following BBA formation, while the control group (n = 3) received saline. The primary outcomes were assessed over an eight-week period post-surgery, and included anastomosis healing, stricture formation, and bile leakage. Histological analysis was performed to evaluate fibrosis, angiogenesis, and inflammation. Immunohistochemistry was conducted to assess healing-related markers (CD34, α-SMA) and the immunological microenvironment (CD3, CD10, tryptase). The SVF-treated group exhibited significantly enhanced healing of the BBA. Histological examination revealed increased angiogenesis and reduced fibrosis in the SVF group. Immunohistochemical staining demonstrated higher vascular density in the anastomosed area of the SVF-treated group (390 vs. 210 vessels per 1 mm2, p = 0.0027), as well as a decrease in wall thickness (1.9 vs. 1.0 mm, p = 0.0014). There were no statistically significant differences in mast cell presence (p = 0.40). Immunohistochemical staining confirmed the overexpression of markers associated with tissue repair. Local injections of autologous SVF at the site of BBA have been demonstrated to significantly enhance healing and promote tissue regeneration. These findings suggest that SVF could be a valuable adjunctive therapy in BBA surgery, potentially improving surgical outcomes. However, further investigation is needed to explore the clinical applicability and long-term benefits of this novel approach in clinical practice as a minimally manipulated cell application.

We've read with great interest the article by Smolinska et al. entitled "Stem Cells and Their Derivatives: An Implication for the Regeneration of Nonunion Fractures" regarding the recent scientific studies dealing with the treatment of nonunion fractures in clinical and preclinical settings using Mesenchymal Stem Cell (MSC)-based therapeutic techniques. Bone tissue regeneration is a dynamic process that involves the restoration of damaged or lost bone structure and function. Traditional approaches such as autografts and allografts, platelet rich plasma (PRP) treatment and cell therapies, have limitations, including donor site morbidity and immunologic concerns, as well as cell culture and processing requirements. In contrast, the use of minimally manipulated cells that do not require culturing has emerged as a promising alternative that offers several advantages in bone tissue regeneration.

Molecular hydrogen (H2) has antioxidant, anti-inflammatory, and anti-fibrotic effects. In a rat model simulating pulmonary fibrotic changes induced by monocrotaline-induced pulmonary hypertension (MPH), we had previously explored the impact of inhaled H2 on lung inflammation and blood pressure. In this study, we further focused the biological effects of H2 on mast cells (MCs) and the parameters of the fibrotic phenotype of the local tissue microenvironment. MPH resulted in a significantly increased number of MCs in both the pneumatic and respiratory parts of the lungs, an increased number of tryptase-positive MCs with increased expression of TGF-β, activated interaction with immunocompetent cells (macrophages and plasma cells) and fibroblasts, and increased MC colocalization with a fibrous component of the extracellular matrix of connective tissue. The alteration in the properties of the MC population occurred together with intensified collagen fibrillogenesis and an increase in the integral volume of collagen and elastic fibers of the extracellular matrix of the pulmonary connective tissue. The exposure of H2 together with monocrotaline (MCT), despite individual differences between animals, tended to decrease the intrapulmonary MC population and the severity of the fibrotic phenotype of the local tissue microenvironment compared to changes in animals exposed to the MCT effect alone. In addition, the activity of collagen fibrillogenesis associated with MCs and the expression of TGF-β and tryptase in MCs decreased, accompanied by a reduction in the absolute and relative content of reticular and elastic fibers in the lung stroma. Thus, with MCT exposure, inhaled H2 has antifibrotic effects involving MCs in the lungs of rats. This reveals the unknown development mechanisms of the biological effects of H2 on the remodeling features of the extracellular matrix under inflammatory background conditions of the tissue microenvironment.

The extracellular matrix is an organized three-dimensional network of protein-based molecules and other macromolecules that provide structural and biochemical support to tissues. Depending on its biochemical and structural properties, the extracellular matrix influences cell adhesion and signal transduction and, in general, can influence cell differentiation and proliferation through specific mechanisms of chemical and mechanical sensing. The development of body tissues during ontogenesis is accompanied by changes not only in cells but also in the composition and properties of the extracellular matrix. Similarly, tumor development in carcinogenesis is accompanied by a continuous change in the properties of the extracellular matrix of tumor cells, called ‘oncomatrix’, as the tumor matures, from the development of the primary focus to the stage of metastasis. In this paper, the characteristics of the composition and properties of the extracellular matrix of tumor tissues are considered, as well as changes to the composition and properties of the matrix during the evolution of the tumor and metastasis. The extracellular matrix patterns of tumor tissues can be used as biomarkers of oncological diseases as well as potential targets for promising anti-tumor therapies.

About 7% of all cancer deaths are caused by pancreatic cancer (PCa). PCa is known for its lowest survival rates among all oncological diseases and heterogenic molecular profile. Enormous amount of genetic changes, including somatic mutations, exceeds the limits of routine clinical genetic laboratory tests and further stagnates the development of personalized treatments. We aimed to build a mutational landscape of PCa in the Russian population based on full exome next-generation sequencing (NGS) of the limited group of patients. Applying a machine learning model on full exome individual data we received personalized recommendations for targeted treatment options for each clinical case and summarized them in the unique therapeutic landscape.

In this study, the optimal engraving parameters were determined through the analysis of scanning electron microscopy (SEM) data, as follows: a laser power density of 5.5 × 105 W/cm2, an irradiation rate of 0.1 mm/s, a well radius of 60 μm, a distance between well centers of 200 μm, and a number of passes for each well of 20. After 1 week of in vitro cultivation, chondrocytes were located on the surface of the scaffolds, in the sockets and lacunae of decellularized cartilage. When implanted into animals, both cellular and acellular scaffolds were able to support cartilage in-growth and complete regeneration of the defect without clear boundaries with normal tissue. Nevertheless, the scaffolds populated with cells exhibited superior biocompatibility and were not subject to rejection, in contrast to cell-free constructs.

Extensive chest wall defects occur in 28% of all sternal resection cases and are a major challenge in thoracic surgery. These cases are generally considered “critical defects” requiring primary or secondary reconstruction using various types of flaps, mesh repairs, bone autografts, or endoprosthesis. The past decade witnessed rapid advances in the application of personalized endoprostheses in thoracic surgery. Surgeons began to use carbon or titanium grafts for personalized sternum replacement. The main advantages of these implants are superior cosmetic effect, biocompatibility, and low risk of infection. Herein, we present a case of a 55-year-old patient with an indication for extended sternum resection due to metastatic thyroid cancer. The patient underwent extended sternum resection, followed by the implantation of a personalized microporous titanium sternum equipped with graspers for atraumatic rib fixation.

We read with great interest the meta-analysis by Mudgal et al. (2024) regarding the effectiveness and safety assessment of stem cell therapy for diabetic foot ulcers. Indeed, The management of chronic wounds requires innovative approaches to avoid unsuccessful outcomes, and stromal cell therapies have emerged as a potential solution for soft tissue repair. A critical aspect of this therapeutic strategy is the role of mast cells in stimulating delayed inflammation through their interactions with various cells as well as the extracellular matrix. Mast cells are critical in orchestrating the inflammatory response and their activation can influence macrophage behavior and secondary healing efficacy. The use of mesenchymal stromal cells in regenerative medicine for diabetic foot ulcers treatment is often limited by their time-limited anti-inflammatory responses. However, these time-limited effects could not achieve the prolonged effects and impact of cell therapy efficacy and the potential enhancement of cell function by biologically active factors such as growth factors or gene therapeutics for prolonged release. The integration of cell and prolonged release gene therapeutics is a promising approach that goes beyond regenerative medicine by preventing secondary inflammatory complications. While mesenchymal stromal cells have shown promising results in experimental and clinical studies, there are limitations to their efficacy in regenerative medicine for diabetic foot ulcers. These limitations include the heterogeneity of cell populations used in the studies, the difficulty in determining the contribution of cells when used in combination with materials, the lack of data on optimal cell numbers for tissue repair, the effect of culture conditions on cell therapy efficacy, and the potential enhancement of cell efficacy by the use of additional biologics such as growth factors or gene therapeutics. The combination of cell and gene therapy is seen as a promising approach that goes beyond regenerative medicine into the field of molecular surgery of chronic wounds.

In 2021, it has been 100 years since the beginning of the scientific career of the famous radiobiologist and geneticist Prof. Nikolay V. Timofeeff-Ressovsky. Among the scientific fields he developed from 1921 to 1981 were physical biology, genetic engineering, the amplifier principle, and population radiobiology. However, it would be unfair to consider that Timofeeff-Ressovsky’s creative contribution was limited to the confines of his laboratory. On the contrary, his unstoppable and passionate creative mind required the expansion of scientific contacts with the world’s best laboratories, biologists, physicists and chemists. This article highlights the connection between the creativity of N.V. Timofeeff-Ressovsky and the works of his contemporaries, as well as the fruitful ideas of today.

The evolution of man on Earth took place under conditions of constant exposure to background ionizing radiation (IR). From this point of view, it would be reasonable to hypothesize the existence of adaptive mechanisms that enable the human organism to safely interact with IR at levels approximating long-term natural background levels. In some situations, the successful operation of molecular mechanisms of protection against IR is observed at values significantly exceeding the natural background level, for example, in cancer cells. In 15–25% of cancer patients, cancer cells develop a phenotype that is resistant to high doses of IR. While further investigations are warranted, the current evidence suggests a strong probability of observing positive health effects, including an increased lifespan, a reduced cancer risk, and a decreased incidence of congenital pathologies, precisely at low doses of ionizing radiation. This review offers arguments primarily based on a phenomenological approach and critically reconsidering existing methodologies for assessing the biological risks of IR to human health. Currently, in the most economically developed countries, there are radiation safety rules that interpret low-dose radiation as a clearly negative environmental factor. Nowadays, this approach may pose significant challenges to the advancement of radiomedicine and introduce complexities in the regulation of IR sources. The review also examines molecular mechanisms that may play a key role in the formation of the positive effects of low-dose IR on human radioadaptive capabilities.

The high sensitivity of living organic forms to space radiation remains the critical issue during spaceflight, to which they will be chronically exposed during months of interplanetary or even decades of interstellar spaceflight. In the human body, all actively dividing and poorly differentiated cells are always close to being damaged by radiological or chemical agents. The chronic exposure to ionizing radiation primarily causes changes in blood counts and intestinal damage such as fibrosis, obliterative vasculitis, changes in the gut microbiota, and atrophy or degeneration of muscle fibers. The project “MISS: Microbiome Induced Space Suit” was presented at the Giant Jamboree of the International Genetically Engineered Machine Competition 2021, with the aim to investigate the ability of the novel microbiota-mediated approach to enhance human resistance to ionizing radiation. The key innovative part of the project was the idea to create a novel radioprotector delivery mechanism based on human gut microbiota with the function of outer membrane vesicles (OMVs) secretion. The project concept proposed the feasibility of genetically modifying the human microbiota in situ through the delivery of genetic constructs to the host’s crypts using silicon nanoparticles with chemically modified surfaces. In this perspective, we discuss the advances in modifying microbiota-mediated secretory activity as a promising approach for radioprotection and as an alternative to hormone therapy and other health conditions that currently require continuous drug administration. Future clinical trials of in situ methods to genetic engineering the crypt microbiota may pave the way for indirect regulation of human cells.

Infertility is an important personal and society disease, of which the male factor represents half of all causes. One of the aspects less studied in male infertility is the immunological testicular microenvironment. Mast cells (MCs), having high potential for regulating spermatogenesis due to fine-tuning the state of the integrative buffer metabolic environment, are one of the most crucial cellular subpopulations of the testicular interstitium. One important component of the MC secretome is proteases that can act as proinflammatory agents and in extracellular matrix (ECM) remodeling. In the testis, MCs are an important cell component of the testicular interstitial tissue (TIT). However, there are still no studies addressing the analysis of a specific MC protease—carboxypeptidase A3 (CPA3)—in cases with altered spermatogenesis. The cytological and histotopographic features of testicular CPA3+ MCs were examined in a study involving 34 men with azoospermia. As revealed, in cases with non-obstructive azoospermia, a higher content of CPA3+ MCs in the TIT and migration to the microvasculature and peritubular tissue of seminiferous tubules were observed when compared with cases with obstructive azoospermia. Additionally, a high frequency of CPA3+ MCs colocalization with fibroblasts, Leydig cells, and elastic fibers was detected in cases with NOA. Thus, CPA3 seems to be of crucial pathogenetic significance in the formation of a profibrogenic background of the tissue microenvironment, which may have direct and indirect effects on spermatogenesis.

>Regulatory changes in senescent cells could potentially affect the composition of extracellular vehicles(EVs), specifically altering their size and cargo. As a result, the released senescent EVs contain an unpredictable cocktail of growth factors and cytokines. These biomolecules have dual effects,potentially guiding the induction of senescence in affected cells and promoting an inflammation-related adomino effectowithin the cellular environment, ultimately leading to tissue inflammaging.Based on this view, we read with great interest the paper by Ding et al.[1] regarding the key biomedical issues of applying mesenchymal stem cell(MSC)-derived EVs for skin wound treatment. EVs secreted by cells have gained significant attention in recent years due to their potential therapeutic applications. These microvesicles are believed to play a crucial role in intercellular communication and have been investigated for their ability to deliver therapeutic cargo to target cells.