The musculoskeletal system, consisting of bones and cartilage of various types, muscles, ligaments, and tendons, is the basis of the human body. However, many pathological conditions caused by aging, lifestyle, disease, or trauma can damage its elements and lead to severe disfunction and significant worsening in the quality of life. Due to its structure and function, articular (hyaline) cartilage is the most susceptible to damage. Articular cartilage is a non-vascular tissue with constrained self-regeneration capabilities. Additionally, treatment methods, which have proven efficacy in stopping its degradation and promoting regeneration, still do not exist. Conservative treatment and physical therapy only relieve the symptoms associated with cartilage destruction, and traditional surgical interventions to repair defects or endoprosthetics are not without serious drawbacks. Thus, articular cartilage damage remains an urgent and actual problem requiring the development of new treatment approaches. The emergence of biofabrication technologies, including three-dimensional (3D) bioprinting, at the end of the 20th century, allowed reconstructive interventions to get a second wind. Three-dimensional bioprinting creates volume constraints that mimic the structure and function of natural tissue due to the combinations of biomaterials, living cells, and signal molecules to create. In our case—hyaline cartilage. Several approaches to articular cartilage biofabrication have been developed to date, including the promising technology of 3D bioprinting. This review represents the main achievements of such research direction and describes the technological processes and the necessary biomaterials, cell cultures, and signal molecules. Special attention is given to the basic materials for 3D bioprinting—hydrogels and bioinks, as well as the biopolymers underlying the indicated products.

Currently, the actual task of modern pharmacy is to study the chemical composition and pharmacological properties of plant objects. Within the framework of this concept, it seems interesting to study Quercus robur L. buds. One of the promising groups of biologically active compounds of Quercus robur L. buds are flavonoids. This group of substances has a wide range of a pharmacological activity, which is significant in the creation of new medicines based on medicinal plant raw materials.The aim of the article was to work out methods for quantitative determination of total flavonoids in Quercus robur l. buds.Materials and methods. The research materials were aqueous-alcoholic extracts from Quercus robur L. buds with 70% ethyl alcohol which were analyzed by differential UV spectrophotometry on spectrophotometer “SF 2000” (Russia).Results. The methods for quantitative determination of total flavonoids in Quercus robur L. buds by differential UV spectrophotometry, has been developed using a standard sample of cynaroside at the analytical wavelength of 400 nm. The optimum parameters for the extraction of total flavonoids from Quercus robur L. buds have been determined. They are: the optimum extractant is 70% ethyl alcohol; the “raw material-extractant” ratio is 1:50; the extraction time is 120 min, the degree of atomization is 2 mm.The content of total flavonoids for Quercus robur L. buds has been determined; it varies from 0.27%±0.01 to 0.44%±0.02. These results make possible to recommend the content of total flavonoids for this type of raw materials not less than 0.25% as a lower limit.Conclusion. The data obtained in the course of the experiment, makes it possible to conclude that a further study of Quercus robur L. buds is promising, and it also contributes to the implementation of medicinal plant raw materials “Quercus robur L. buds” in the State Pharmacopoeia (Russia).

АНТИМИКРОБНАЯ АКТИВНОСТЬ ВОДНО-СПИРТОВЫХ ИЗВЛЕЧЕНИЙ ЛИСТЬЕВ И ПОЧЕК ДУБА ЧЕРЕШЧАТОГО (QUERCUS ROBUR L.)

The current paper highlights the active development of tissue engineering in the field of the biofabrication of living tissue analogues through 3D-bioprinting technology. The implementation of the latter is impossible without important products such as bioinks and their basic components, namely, hydrogels. In this regard, tissue engineers are searching for biomaterials to produce hydrogels with specified properties both in terms of their physical, mechanical and chemical properties and in terms of local biological effects following implantation into an organism. One of such effects is the provision of the optimal conditions for physiological reparative regeneration by the structural components that form the basis of the biomaterial. Therefore, qualitative assessment of the composition of the protein component of a biomaterial is a significant task in tissue engineering and bioprinting. It is important for predicting the behaviour of printed constructs in terms of their gradual resorption followed by tissue regeneration due to the formation of a new extracellular matrix. One of the most promising natural biomaterials with significant potential in the production of hydrogels and the bioinks based on them is the polymer collagen of allogeneic origin, which plays an important role in maintaining the structural and biological integrity of the extracellular matrix, as well as in the morphogenesis and cellular metabolism of tissues, giving them the required mechanical and biochemical properties. In tissue engineering, collagen is widely used as a basic biomaterial because of its availability, biocompatibility and facile combination with other materials. This manuscript presents the main results of a mass spectrometry analysis (proteomic assay) of the lyophilized hydrogel produced from the registered Lyoplast^® bioimplant (allogeneic human bone tissue), which is promising in the field of biotechnology. Proteomic assays of the investigated lyophilized hydrogel sample showed the presence of structural proteins (six major collagen fibers of types I, II, IV, IX, XXVII, XXVIII were identified), extracellular matrix proteins, and mRNA-stabilizing proteins, which participate in the regulation of transcription, as well as inducer proteins that mediate the activation of regeneration, including the level of circadian rhythm. The research results offer a new perspective and indicate the significant potential of the lyophilized hydrogels as an effective alternative to synthetic and xenogeneic materials in regenerative medicine, particularly in the field of biotechnology, acting as a matrix and cell-containing component of bioinks for 3D bioprinting.

Objective. To study the anti-inflammatory effects of the “Alvostaz-sponge” medical product for the treatment of chronic periodontitis. Materials and methods. The culture of juvenile human dermal fibroblasts was treated with TNF-α (1st series of experiments) and a mixture of TNF-α with “Alvostaz-sponge” extract (2nd series of experiments). The concentration of cytokines IL-6, MCP-1 in the culture medium of fibroblasts was assessed using enzyme immunoassay (ELISA). The examination and treatment of 74 patients (49 women and 25 men), with a diagnosis of chronic generalized periodontitis of moderate severity were carried out. Results. In response to TNF-α stimulated inflammation, fibroblasts sharply increased the production of both chemokine MCP-1 and the inflammatory mediator IL-6 into the culture medium. A dose-dependent rise of “Alvostaz-sponge” extract content in the culture medium correlated with a decrease in the concentration of MCP-1, which indicates a pronounced inhibitory effect of “Alvostaz-sponge” extract on the production of MCP-1 cytokine. An increase in the concentration of IL-6 correlated with a dose-dependent increase in the extract of “Alvostaz sponge” in the culture medium of TNF-α-stimulated fibroblasts. Conclusions. The results of the study demonstrated “Alvostaz-sponge” medication to be a powerful inhibitor of chemokine MCP-1 production and, it is due to this effect that it restricts the monocyte cells migration into the periodontal pocket zone. The obtained results of the treatment show accelerated healing of the periodontal complex when using the “Alvostaz-sponge” remedy.

Background. By-products of human donor plasma fractionation often possess untapped potential for regenerative medicine. However, they are frequently excluded from further technological processing, and a comprehensive physicochemical and biological characterization remains lacking – a gap that hinders the development of novel, effective biomaterials. Objective. To perform an integrated physicochemical and biological analysis of fibrinogen-containing precipitate No. 1 (FР No. 1) – a by-product of donor plasma fractionation – and to evaluate its potential as a raw material for biomedical applications. Materials and Methods. A multi-method approach was employed, including Fourier-transform infrared (FTIR) spectroscopy, UV spectrophotometry, scanning electron microscopy (SEM), SDS‑PAGE electrophoresis, quantitative determination of protein mass fraction, assessment of fibrinogen extraction yield in citrate buffer and phosphate-buffered saline (37 °C, 5 hours), as well as in vitro biological testing on human dermal fibroblast cultures. Results. FP No. 1 was found to preserve the structural integrity of fibrinogen with low levels of impurities. The lyophilizate formed porous fibrin matrices with pore sizes ranging from 100 to 180 μm. Cell viability upon contact with the material reached 96.5 % (p 0.05), confirming the absence of cytotoxicity. The protein mass fraction in the dry substance was 77 %. Under optimal extraction conditions, the fibrinogen yield reached 21.9 % (citrate buffer) and 21.5 % (phosphate-buffered saline). Conclusion. FP No. 1 represents a highly promising secondary protein raw material for the development of bioinks for 3D bioprinting, wound dressings, and tissue-engineered constructs. These findings strongly advocate for the rational reintegration of plasma fractionation by‑products into high‑technology biomedical applications.