The effect of 3D-printed Ti6Al4V scaffolds with various macropore structures on osteointegration and osteogenesis: A biomechanical evaluation

A properly designed porous scaffold can accelerate the osseointegration process, and the use of computer-aided design (CAD) and additive manufacturing (AM) techniques has the potential to improve the traditional porous scaffold approach. In this study, we evaluate the effect of porous Ti6Al4V (Ti) with different pore structures on osteointegration and osteogenesis. Porous Ti scaffolds with different pore structures based on four commercially available implants were designed and manufactured by CAD and selective laser melting (SLM). Micro-CT showed that SLM was able to produce Ti scaffolds with different pore structures. The mechanical properties evaluated by finite element analysis and compression tests indicated that the four porous scaffolds in our study were mechanically adapted, despite their different mechanical properties. Then, we used 3D-printed porous discs to culture human bone marrow mesenchymal stem cells (hBMMSCs), the main seed cells of bone tissue engineering. The results showed no significant difference among the four groups in cell morphology, viability and proliferation. In addition, four groups showed a comparable mineralization ability even though Ti-g had a higher alkaline phosphatase activity (ALP). In vivo tests in a rabbit model showed that all four groups were suitable for new bone ingrowth and integration. These findings indicate that the four different pore structures in the Ti scaffolds provided good osteointegration and osteogenesis.