THE EFFECT OF MULTIAXIAL DEFORMATION ON THE DYNAMICS OF BIODEGRADATION AND CELL COLONIZATION OF ALLOY WE43

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