This research paper is concerned with fibrin glues, used as effective tools to stop bleeding in the case of wounds and surgical interventions. The paper provides data on the various fibrin glues—both currently used in practice and being developed, their sources, mechanisms of action, and properties. Such glues are biocompatible and are characterized by good adhesive and hemostatic properties. These characteristics mean that fibrin glues are currently widely used across a range of surgical applications. Such glues can be used independently or in combination with mechanical techniques, being particularly suitable for difficult-to-access parts of the body. The combined use of fibrin glues with various biologically active substances (BASs)—such as antibiotics and growth factors—and with cell therapy is a promising approach. Such adjuncts enhance the effectiveness of the glues and help to optimize the therapies. This research paper presents the latest data from studies using various experimental models demonstrating the increased efficacy of fibrin glues used in combination with BASs. We also report on the ongoing development of new fibrin glues for long-term use and with optimized formulations. Studies on the interactions of these glues with cells and tissues are supporting the creation of a new generation of fibrin glues with adjustable properties.

New stable three-dimensional hydrogels were obtained in an inert gas atmosphere in light in an aqueous dispersion of the main components: cod collagen, methyl methacrylate, polyethylene glycol, RbTe_1.5W_0.5O₆ complex oxide, and modifying additives. The analysis of the new hydrogels’ cytotoxicity using the MTT assay showed that the cytotoxicity of the sample extracts was observed in a number of examples, but was decreased with increasing dilution of the extracts. The decrease in cell viability at high concentrations of the extract is likely caused by a decrease in the number of specific components of the complete culture medium used to produce extracts. It is related to the well-known adsorption of medium proteins by the gel component, high-molecular compounds included in the matrix. The stimulating effect of the substances included in its composition was observed with a significant dilution of the extract, i.e., the proliferative activity of the cells increased. The extract of the hydrogel hydrolysate sample and all its dilutions did not show cytotoxicity in the MTT assay examples. It determines the prospect of its use on the wound surface, since hydrogel destruction occurs under the action of body enzymes. The new hydrogel is a promising material for creating wound coverings or scaffolds.

Recent decades have been characterized by increasing numbers of bone tissue injuries and diseases resulting in the formation of bone defects. The number of such bone defects has also grown due to active surgical approaches implemented after surgical interventions for oncological, infectious, and dystrophic bone lesions. To repair such bone defects requires the use of bone tissue substitutes. Nowadays, constructs based on matrices of various compositions and structures, supplemented with the addition of biologically active components (including growth factors and cells), are the most promising approaches used in bone tissue engineering. The properties of the matrices are of the utmost importance in construct formation. This work presents the results of a comprehensive study of matrices of various natures intended for the formation of complex constructs for bone tissue engineering. Using a set of methods for studying the physical, mechanical, and biological characteristics, the total and associated porosity of the studied matrices, the structure, the mechanical parameters, and the level of cytotoxicity and cytocompatibility were determined. It was shown that all the studied materials were not cytotoxic (cytotoxicity rank of all matrices = 0–1). All matrices were porous, but samples of materials of biological origin had large pores ranging in size from 100 to 1000 μm, and pores of the hybrid polymer were sized from 0.1 to 100 μm. Total and open porosity ranged from 89% and 79% for the allogeneic matrix up to 67% and 48% for the hybrid polymer, respectively, while the σ values (compressive stress at break) of samples of all studied materials were close to each other. When human test culture MSCs interact with samples of these materials, it was shown that the cells adhere to the surface and structure of all materials and retain typical morphology, while also demonstrating the ability to proliferate and migrate along the surface and into the matrix structure, i.e., all materials are cytocompatible. Based on the data obtained, it can be assumed that all the studied matrices can be used for model biomedical studies and as a basis for constructs for bone tissue engineering. An adequate choice of research method at the earliest stages of the development of each material will ensure the most effective approaches for further work and subsequent use of this product.

Improving the restoration of skin defects of various etiologies continues to be an important medical challenge globally. This primarily applies to the treatment of chronic wounds and major burns, which create particularly complex and socially significant problems for surgery. In recent decades the progress in these fields has largely been associated with techniques for regenerative medicine, specifically, techniques based on the use of tissue-engineered constructs. Before their use in clinical practice, all such newly developed constructs require preclinical studies to confirm their safety and effectiveness in animal models. This paper presents the results of preclinical studies of the effectiveness of restoration of full-layer degloving wounds in pigs using grafts of either an original biopolymer hydrogel scaffold or a skin equivalent based on it, but seeded with autologous skin cells (ASCs). It is demonstrated that the scaffold itself integrates into the wound bed tissues, facilitating cell recruitment and the accumulation and early maturation of granulation tissue. Then, at later stages of regeneration, the scaffold accelerates the maturation of connective tissue and promotes the formation of tissues similar to those of healthy skin in terms of thickness and structure. Owing to the ASCs present in it, the skin equivalent demonstrates greater effectiveness than the scaffold alone, in particular, due to overall faster remodeling of the graft connective tissue. Therefore, the scaffold we have developed and the skin equivalent based on it have much potential as products for the repair of skin wounds.

In vitro screening of biocompatibility of modified polyetheretherketone as an implant material: Cytotoxicity and cell adhesion | Khashirov | Extreme Medicine Скрининг in vitro биосовместимости модифицированного полиэфирэфиркетона как материала для имплантатов: цитотоксичность и клеточная адгезия | Хаширов | Экстремальная биомедицина

HighlightsThe method for determining the viability of mesenchymal stem cells in the composition of tissue-engineering constructs is proposed here. This method can become an effective tool for regenerative medicine and tissue engineering for assessing the mechanisms of the regenerative process when using tissue-engineered constructs and predicting their effectiveness in an in vitro system. AbstractAim. Еxperimental substantiation of the efficiency of the method for determining the viability of mesenchymal stem cells in tissue-engineered constructs during regenerationMethods. The experimental study was conducted on 12 animals (rats). A full-layer scalped wound with a diameter of 3 cm was formed in the animals. A tissue-engineering construct based on human plasma cryoprecipitate was implanted into the wound, with the composition of which a suspension of rat mesenchymal stem cells (MSCs) pre-stained with the DiOC₁₄(3) tracer was introduced. At the control periods (3, 7–8, 14 and 21 days), the animals were withdrawn from the experiment. During the operation, the wound defect area was cut out for ex-tempore examination using wide-field fluorescence microscopy with visualization of samples with 40×, 100×, 200× magnification in the GFP fluorescence channel.Results. When examining the material obtained from animals on day 3, the external characteristics of the overwhelming majority of identified objects with characteristic fluorescent glow corresponded to the morphological characteristics of MSCs – spindle-shaped cells with characteristic processes. In the material obtained from experimental animals on days 7–8, a large number of cells stained with a tracer fluorescent membrane dye were also detected, which had a green fluorescent glow and characteristic morphology. In the biomaterial obtained on day 14 of the experiment, the number of objects with characteristic MSC morphology stained with the DiOC₁₄(3) tracer was significantly less than on days 3 and 7–8 of the experiment. On day 21, a signal specific for the DiOC₁₄(3) tracer was also detected, but it was not possible to visualize even single cells with the morphology characteristic of MSCs; the signal was probably due to fragments of membranes of eliminated MSCs labeled with a fluorescent dye.Conclusion. It was shown that MSCs in tissue-engineering constructs implanted on the animal wound retain viability and characteristic morphology for at least 14 days. It is important that the proposed method allows intravital visualization and photofixation of viable MSCs with characteristic morphology, and thus avoiding distortions that may be associated with fixation of biological material. The proposed method can become an effective tool for regenerative medicine and tissue engineering in relation to assessing the mechanisms of the regenerative process using TECs and predicting their effectiveness in the in vitro system.