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.

Background/Objectives: Radiobiology has shown heterogeneity in the sensitivity of cells to ionizing radiation, depending on a variety of conditions. The presence of an extracellular matrix (ECM) appears to confer a radioprotective effect on cells and can influence the cellular microenvironment by modulating the availability of oxygen and nutrients, which can affect cellular metabolism and stress responses. A three-dimensional cell culture allows the synergistic effect on cell survival to be obtained based not only on the radioprotective properties of the extracellular matrix but also on the stress-resistant endogenous properties of the cell culture. The aim of this study was to investigate the survival of chondrocytes in a 3D cell culture during high-dose ionizing irradiation. Methods: The properties of nasal chondrocytes were evaluated using a pellet culture model in which the cells were surrounded by a de novo synthesized extracellular matrix. Tissue cultures were exposed by gamma radiation at doses of 10, 100, and 1300 Gy. Cell viability was assessed after 2 days of irradiation by live/dead staining using confocal scanning laser microscopy. Results: Tissue-cultured chondrocytes survive after gamma-irradiation of low (10 Gy), medium (100 Gy), and high (1300 Gy) dosages; however, after irradiation of 1300 Gy, the percentage of surviving cells was lower. The average percentages of viable cells were evaluated as 82%, 79%, and 63% in low-, medium-, and high-dose groups, respectively. Conclusions: Under determined conditions, human cells are able to survive at doses of ionizing radiation that are significantly higher than the current limits.

Non-ionizing radiation and excited states can modify the properties of biological tissues, altering their structure, surface morphology and mechanical properties of the extracellular matrix, and stimulating resident cells. The primary goal of non-ionizing radiation applications is to achieve high precision and controllability in the processes of modifying biological tissues, allowing for the minimization of damage to surrounding healthy tissues and improving repair processes. The use of the photonic and acoustic methods can contribute to the creation of new materials with specific biological properties, which is particularly important for the development of individualized implants, efficient drug delivery systems, and tissue engineering methods. An important aspect is the development of integrated approaches that combine different types of non-ionizing radiation to achieve a synergistic effect we term a "bosonic concentrate." For example, the combination of photonic and phononic ultrasonic therapy can improve the penetration of drugs into deeper tissue layers, while the combination of photothermal and acoustic exposure can increase the precision and efficiency of tumor cell removal. This review discusses the effects underlying the potential treatment options for biological tissue modification to improve their physiological relevance based on various bosonic concentrate combinations. In particular, we will discuss how low-energy acoustic phonons (characteristic energy 0.03-0.1 eV) could create tissue-specific spatially resolved structures that serve as matrices for optical photons (1-3 eV) and excitons (~0.1 eV) and how they could be focused and dissipated to mediate biochemical reactions. All of them are capable of propagating in living tissues, mediating changes at the cellular and molecular levels.

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.

Gelatin methacryloyl (GelMA) has recently attracted increasing attention. Unlike other hydrogels, it allows for the adjustment of the mechanical properties using such factors as degree of functionalization, concentration, and photocrosslinking parameters. In this study, GelMA with a high degree of substitution (82.75 ± 7.09%) was synthesized, and its suitability for extrusion printing, cytocompatibility, and biocompatibility was studied. Satisfactory printing quality was demonstrated with the 15% concentration hydrogel. The high degree of functionalization led to a decrease in the ability of human adipose-derived stem cells (ADSCs) to adhere to the GelMA surface. During the first 3 days after sowing, proliferation was observed. Degradation in animals after subcutaneous implantation was slowed down.

The aim of this study was to verify the applicability of high-concentration collagen-based bioink with MSC (ADSC) and decellularized ECM granules for the formation of cartilage tissue de novo after subcutaneous implantation of the scaffolds in rats. The printability of the bioink (4% collagen, 2.5% decellularized ECM granules, derived via 280 μm sieve) was shown. Three collagen-based compositions were studied: (1) with ECM; (2) with MSC; (3) with ECM and MSC. It has been established that decellularized ECM granules are able to stimulate chondrogenesis both in cell-free and MSC-laden scaffolds. Undesirable effects have been identified: bone formation as well as cartilage formation outside of the scaffold area. The key perspectives and limitations of ECM granules (powder) application have been discussed.

Transfer of regenerative approaches into clinical practice is limited by strict legal regulation of in vitro expanded cells and risks associated with substantial manipulations. Isolation of cells for the enrichment of bone grafts directly in the Operating Room appears to be a promising solution for the translation of biomedical technologies into clinical practice. These intraoperative approaches could be generally characterized as a joint concept of tissue engineering in situ. Our review covers techniques of intraoperative cell isolation and seeding for the creation of tissue-engineered grafts in situ, that is, directly in the Operating Room. Up-to-date, the clinical use of tissue-engineered grafts created in vitro remains a highly inaccessible option. Fortunately, intraoperative tissue engineering in situ is already available for patients who need advanced treatment modalities.

: Numerous clinical studies have shown a wide clinical potential of mesenchymal stromal cells (MSCs) application. However, recent experience has accumulated numerous reports of adverse events and side effects associated with MSCs therapy. Furthermore, the strategies and methods of MSCs therapy did not change significantly in recent decades despite the clinical impact and awareness of potential complications. An extended understanding of limitations could lead to a wider clinical implementation of safe cell therapies and avoid harmful approaches. Therefore, our objective was to summarize the possible negative effects observed during MSCs-based therapies. We were also aimed to discuss the risks caused by weaknesses in cell processing, including isolation, culturing, and storage. Cell processing and cell culture could dramatically influence cell population profile, change protein expression and cell differentiation paving the way for future negative effects. Long-term cell culture led to accumulation of chromosomal abnormalities. Overdosed antibiotics in culture media enhanced the risk of mycoplasma contamination. Clinical trials reported thromboembolism and fibrosis as the most common adverse events of MSCs therapy. Their delayed manifestation generally depends on the patient's individual phenotype and requires specific awareness during the clinical trials with obligatory inclusion in the patient' informed consents. Finally we prepared the safety checklist, recommended for clinical specialists before administration or planning of MSCs therapy.

The study was aimed at the applicability of a bioink based on 4% collagen and chondrocytes for de novo cartilage formation. Extrusion-based bioprinting was used for the biofabrication. The printing parameters were tuned to obtain stable material flow. In vivo data proved the ability of the tested bioink to form a cartilage within five to six weeks after the subcutaneous scaffold implantation. Certain areas of cartilage formation were detected as early as in one week. The resulting cartilage tissue had a distinctive structure with groups of isogenic cells as well as a high content of glycosaminoglycans and type II collagen.

Introduction. Biological dose uniformity in SOBP of the modem proton therapy facilities is an important issue. The results of a number of studies reveal an increased biological efficiency at the distal area of SOBP.The aim of the study was to verify this effect for Prometeus facility, which provides proton therapy with a scanning pencil beam.Material and methods. The study was conducted at A. Tsyb MRRC. Melanoma B16F10 cells were used for the experiments. The biological efficacy of protons was evaluated by clonogenic assay (cell survival) and comet assay (DNA damage). Proton dose range within the experiments was 4-8 Gy. Cells were irradiated both in monolayer and suspension conditions. Proton biological efficacy along SOBP was evaluated in the proximal, middle and distal positions. All irradiations were carried out with one field.Results of in vitro experiments indicate that Prometeus facility treatment planning system in case of single-field irradiation provides the uniformity of the biological dose in SOBP. According to cell survival, there is a tendency for a slightly greater efficiency of protons in the proximal part of SOBP. Data on DNA damage confirm this conclusion.Conclusion. Therefore, unlike a number of modern installations for proton therapy in the case of the facility used in the study, there is no increase of biological dose in the distal area of SOBP.