The comparison of properties of Ti-6Aluminum-4Vanadium porous scaffolds fabricated through low-power selective laser Melting and electron beam melting

Abstract

Background and Purpose: Three-dimensional printing (3DP) selective laser melting (SLM) and electron beam melting (EBM) technique can construct porous Ti-6Aluminum-4Vanadium (Ti-6Al-4V) scaffolds with special microstructural and biomechanical properties. However, it is still needed to be tested for bone tissue engineering. Materials and Methods: To investigate the microstructure and surface modification of a porous titanium scaffold, 3DP-SLM technique was used, and the mechanical and biological performance of the scaffolds was compared with that fabricated by EBM technique. Ti-6Al-4V scaffolds were computer-designed and fabricated using low-power SLM (L-SLM). The microstructure morphologies of L-SLM Ti-6Al-4V (L-SLM-Ti) scaffolds were determined and compared with EBM-fabricated Ti-6Al-4V (EBM-Ti) scaffolds. Each scaffold was immersed with marrow clot for 1 h until fully combined with bone mesenchymal stem cells in clots. The biomechanical and cellular response of these two kinds of Ti-6Al-4V scaffolds were compared. Results: The L-SLM-Ti scaffolds showed a microstructure closer to the designed parameters than that of the EBM-Ti scaffolds. The L-SLM-Ti scaffold fibers had a rougher surface than the EBM-Ti scaffolds. Meanwhile, L-SLM-Ti scaffolds had a lower elasticity modulus and lower bearing force than EBM-Ti scaffold. Cell proliferation and the relative expression levels of OPN, COL1, and RUNX2 in L-SLM-Ti scaffolds was apparently higher than in the EBM-Ti scaffolds, with no significant difference found between the percentage of live cells found in L-SLM-Ti and EBM-Ti scaffolds. Conclusion: 3DP-Ti-6Al-4V scaffolds fabricated by L-SLM and designed with rougher surfaces and larger pore sizes may have more reasonable biomechanical properties and increased biological performance than traditional EBM-Ti scaffolds. These L-SLM-Ti scaffolds might be suitable candidates for bone defect repair.