Role of Triply Periodic Minimal Surface Ti6Al4V ELI alloy lattices fabricated by L-PBF method on cell behavior and inflammatory response  

Abstract Triple Periodic Minimal Surface lattices have been introduced to dental and medical devices. Numerous designs of these porous structures have been proposed, but the biomechanical effects of the different topographic lattices are not fully understood. So, this study aimed to examine the cell and inflammatory responses to different lattice designs, including strut-based and surface-based lattices. Human osteoblasts, human umbilical vein endothelial cells, and monocytes were used to evaluate cell proliferation, osteogenic differentiation, and inflammatory response on lattices after surface treatment strategies. Post-surface treatment of chemical etching, besides improving the surface roughness by removing some adhered metal powder, also modulated the surface energy. Lattice design had no significant impact on cell proliferation, but higher cell proliferation was found in post-surface treated lattices, regardless of topographic design. For angiogenesis, there was no difference in the release of pro-angiogenic growth factors between topographic designs or post-surface treatment groups. Moreover, lattices with the post-surface treatment were prone to have lower inflammation phenotype when compared to as-printed lattice, though not in a significant manner. This study suggests that different topographic lattice designs may not have a major impact on bone ingrowth, but post-surface treatment and surface properties of lattice could suppress a macrophage-induced inflammatory response.