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Titanium alloys have been used for medical purposes for over 60 years. They are used in the manufacture of artificial heart valves, stents of blood vessels, endoprostheses of bones and joints (shoulder, knee, hip, elbow), for auricle reconstruction, in facial surgery, and also as dental implants. In first-generation materials (such as commercially pure titanium or VT6 alloys), the matrix consisted of the α-Ti phase or α-Ti and β-Ti mixture. Unfortunately, implants made of first-generation materials require replacement after 10–15 years of usage. This is due to the degradation of implants and loss of contact with the bone. Recently, these materials have been replaced by β-Ti alloys. These second- generation materials make it possible to exclude the harmful effect of aluminum and vanadium ions released during the gradual implant corrosion, and their elastic modulus is closer to the values for living bone than those for α and α+β alloys. Important areas in the development of β-Ti alloys include increasing their mechanical strength, fatigue strength, corrosion resistance and biocompatibility. New methods for the production and thermo-mechanical processing of titanium alloys arise and develop such as additive technologies or severe plastic deformation. Expensive alloying elements (such as tantalum, zirconium or niobium) are quite successfully replaced with cheaper ones (for example, chromium and manganese). As a result, the properties of titanium implants are gradually getting closer to that of the human bone, and their service life is steadily increasing. Therefore, this paper describes a comparative analysis conducted in relation to β-titanium-based alloys for medical applications.

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