Comparison of selective laser melted commercially pure titanium sheet-based triply periodic minimal surfaces and trabecular-like strut-based scaffolds for tissue engineering

This systematic comparison between sheet-based-TPMS and strut-based ordered and disordered Lattice topologies offers insights into parametric designs for tissue engineering scaffolds intended as implants in regenerative medicine. The study explores the effect of topology on compressive properties and in vitro osteoblastogenesis. TPMS-sheet Gyroid and IWP, Voronoi-tessellation with varying levels of sharpness and BCC-orthogonal Lattices were studied. Disparities between the design intent and the as-manufactured scaffolds that are intrinsic to the SLM manufacturing process are considered to ensure actual porosity and surface-area-per-unit-volume, two important factors in tissue engineering, are consistent across the set. Surface analysis reports the presence of a micro-porosity created by partlysintered cpTi particles. The TPMS topologies display a stretching-dominated deformation and the strut-based disordered ones a bending-dominated double-shear failure. Although the trabecular-like structures exhibit an enhanced compressive behaviour when the designed topology was smoothed, they are more prone to printing imperfections with the sharper 2 finishes. The in vitro studies reveal that the trabecular-sharp topology displays a faster proliferation rate, explained by concavity-driven cellular growth, but its smooth counterpart promotes a larger differentiation extent, outperforming TPMS, as it is aided by larger pore throats lined with a micro-porosity at the scale of osteoblastic geometric features.