The study shows that multiaxial deformation (MAD) treatment leads to grain refinement in magnesium alloy WE43. Compared to the initial state, the MAD-processed alloy exhibited smoother biocorrosion dynamics in a fetal bovine serum and in a complete cell growth medium. Examination by microCT demonstrated retardation of the decline in the alloy volume and the Hounsfield unit values. An attendant reduction in the rate of accumulation of the biodegradation products in the immersion medium, a less pronounced alkalization, and inhibited sedimentation of biodegradation products on the surface of the alloy were observed after MAD. These effects were accompanied with an increase in the osteogenic mesenchymal stromal cell viability on the alloy surface and in a medium containing their extracts. It is expected that the more orderly dynamics of biodegradation of the WE43 alloy after MAD and the stimulation of cell colonization will effectively promote stable osteosynthesis, making repeat implant extraction surgeries unnecessary.

Background. Hydrogels are promising for use in tissue engineering for the restoration and regeneration of various tissues, since they are able to perform the functions of bulk scaffolds, providing the formation of 3D cell structures. Population of such scaffolds with autologous or heterogeneous mesenchymal multipotent stromal cells in vitro makes it possible to localize these cells in the area of target tissues after implantation in a patient. One of the difficult tasks is the choice of the method and mode of sterilization of the hydrogel, which does not change its properties.Aim. Study of the effectiveness of hydrogel sterilization by an accelerated electron beam in various modes, changes in the structure and biocompatibility of the scaffold, to assess the prospects for its use for medical purposes, including as a platform for mesenchymal stromal cells.Materials and methods. We used a hydrogel based on 4 % solutions of sodium alginate and sodium salt of carboxymethyl cellulose, cross-linked with calcium chloride, which was developed, obtained and provided for our research by the team of the Research and Educational Center for Biomedical Engineering of the National University of Science and Technology “MISIS”. Hydrogel samples loaded with Escherichia coli, Lactobacillus acidophilus, Saccharomyces cerevisiae were subjected to electron beam treatment in the range of 5–100 kGy. After electron beam treatment of hydrogel, the presence of living microorganisms and its structure were evaluated by IR-Fourier spectroscopy, as well as the phenotype and formation of 3D structures by mesenchymal multipotent cells.Results. It was found that the treatment of hydrogels with an electron beam at a mode of 25 kGy ensures the death of microorganisms, but does not destroy the structure of the hydrogel and does not inhibit the ability to form capillary-like structures by mesenchymal multipotent cells.Conclusion. Treatment with an accelerated electron beam at a 25 kGy can be used to sterilize hydrogels to obtain bulk scaffolds for cell engineering implants.

Conditioning regimens prior to hematopoietic stem cell transplantation (HSCT) are often accompanied by a period of aplasia characterized by severe neutropenia, anemia, and thrombocytopenia. Long-term antibacterial and immunosuppressive therapy in patients with graft-versus-host disease (GVHD) exacerbates hematopoietic depression. Colony-stimulating factors, erythropoietins, and thrombopoietin receptor agonists are used to correct hematological dysfunction in these patients. However, these drugs have side effects, and their stimulating effect, as a rule, is limited to one of the hematopoietic lineages. At the same time, in patients after HSCT, for the prevention and treatment of hematopoietic disorders against the background of GVHD, it is necessary to use drugs that promote the restoration of all hematopoietic cell lines. Inducers of Toll- and NOD-like receptors, stimulators of emergency hematopoiesis, can be considered as promising drugs for this category of patients. These compounds include bacterial derivatives and sulfated poly(oligo)saccharides capable of stimulating hematopoiesis, which allows us to consider them as promising stimulants of hematopoiesis for the treatment and prevention of disorders of the immune status and hematopoiesis in GVHD.

Introduction. The development of materials for bioresorbable implants is an urgent issue in medicine and materials science. Magnesium alloys are promising materials for this purpose. In particular, alloy WE43 (Mg-Y-Nd-Zr) has proven itself well in this field. However, the use of magnesium alloys is limited by a high degradation rate, which is often accompanied with nonuniform corrosion, which negatively affects the load bearing capacity of the product. In addition, the increased degradation rate usually seriously worsens the biocompatibility of magnesium alloys. Therefore, the study of the corrosion resistance of magnesium alloys, as well astheir biocompatibility, is an urgent task.Purpose of the study was to investigate the effect of multiaxial deformation (MAD), aimed at increasing the mechanical characteristics of the alloy WE43, on its biodegradation kinetics, as well as on cell colonization.Materials and methods. The alloy WE43 in two states  – homogenized (WE43 hom) and strengthened by MAD (WE43 MAD) was investigated in this work. The kinetics of biodegradation was investigated on an xCELLigence RTCA Systems analyzer. A method for estimating the volume of hydrogen was used to study the process of gas formation, which was recorded using an automated digital microscope LionheartTM FX. The corrosive medium was a solution based on Dulbecco’s Modified Eagle’s Medium. A culture of mesenchymal multipotent stromal cells was used to study the colonization of the alloy surface by cells.Results. MAD of the alloy WE43 leads to a decrease in the biodegradation rate and the intensity of gas formation. The period of stabilization of biodegradation for the alloy after the MAD is 16 hours versus 3 hours for the alloy after homogenization. In this case, the volume of released hydrogen was 65.0 ± 4.4  mm3H2/mm3 alloy and 211.0 ± ± 21.1 mm3H2/mm3 alloy for the alloy after MAD and homogenization, respectively. MAD improves the biocompatibility of the alloy WE43, stimulating the colonization of mesenchymal multipotent stromal cells.Conclusion. MAD reduces biodegradation and improves the biocompatibility of the alloy WE43, which makes it a promising medical material, including for the purposes of oncoorthopedics