Comparison of electron beam melting fabrication of irregularity porous Ti-6Al-4V and Ti-24Nb-4Zr-8Sn titanium alloy Scaffolds: cytocompatibility and osteogenesis

AZ227 ePOSTER BASIC RESEARCH

Background: Medical titanium alloys have been widely used in orthopedic implants due to their high specific strength, excellent biocompatibility, and corrosion resistance, but they also face some challenges. Porous titanium alloy scaffolds can effectively solve some problems, but which titanium alloy to choose, and whether the larger the pore diameter of the scaffolds is, the more conducive to osteogenesis or the smaller the better, especially in irregular pore diameter scaffolds, are still controversial.

Aim/Hypothesis: The irregular pore size Ti6Al4V and Ti2448 scaffolds were distinguished and compared according to their pore size. The effects of different titanium alloy components and pore size on the physical and chemical properties and biological properties of titanium alloy scaffolds were evaluated.

Materials and Methods: Ti-6Al-4V(Ti6Al4V) and Ti-24Nb-4Zr-8Sn (Ti2448) were used to print irregular porous scaffolds with pore sizes of 800 μm(P8), 900 μm(P9) and 1000 μm(P10), with electron beam melting (EBM), and the surface characteristics, mechanical properties and biological properties of the materials were tested.

Results: The irregular porous scaffolds were designed using Within the Medica software. Then use EBM for 3D printing. After the printing is completed, physical and chemical properties and biological properties are tested. The volume and surface area of the two metal scaffolds were measured by MCT. SEM was used to detect the surface structure and metal powder residue. The chemical composition of the scaffold was determined by XRD and EDS. The surface wettability, elastic modulus and compressive strength were measured and analyzed. During the in vitro cell experiments, the dead and alive cells were observed by color fluorescence microscope, and the cell proliferation was observed by CCK8. The cell adhesion to titanium alloy scaffold was observed by SEM. RT-PCR and ALP were used to detect the expression level of osteoblasts and the activity of alkaline phosphatase.

Conclusions and Clinical Implications: The results of this study demonstrated that with the increase of the pore size of titanium alloy metal scaffolds, the cell adhesion and proliferation on the surface of the scaffolds also increased gradually, which is easier to promote the differentiation of osteoblasts. The biocompatibility of Ti2448 porous scaffolds was better than that of Ti6Al4V. Ti2448 porous scaffold with large pore size is an ideal implant material.

Keywords: Irregular porous structure, EBM, Pore size, Ti6Al4V, Ti2448