Pore size assessment in triply periodic minimal surface structures for tissue engineering applications

Pore size assessment is crucial in tissue engineering (TE) applications for mechanical and transport properties. Pore size plays a determinant role in cell seeding and migration, but also in regulating mechanotransduction stimuli under in vivo and in vitro conditions. This work is focused on evaluating the pore size distribution (PSD) in TE scaffolds using a segmentation-based pore size assessment methodology. The scaffolds under analysis are based on the triply periodic minimal surface (TPMS) method, with controlled porosity profiles and lattice unit sizes (Fischer–Koch S (FKS) surface, Schwartz diamond (SD), Schoen gyroid (SG) and Schwartz primitive (SP). Lattice unit sizes under 1.625 mm, with porosities between 50% and 80%, provide optimal pore size values for bone TE (BTE) applications (300–800 µm), compared to larger sizes. The FKS surface scaffolds present the lowest pore diameters. SP scaffolds present the largest, but these also displayed a wide PSD amplitude, which might be a disadvantage for applications requiring more uniform fluid channels. This work demonstrates that porosity and lattice unit size can be tuned for optimal PSD, which can be linked with further stiffness and permeability tuning. Porous structures for TE applications and other engineering fields can be developed with controlled pore size, evolving from porosity-controlled frameworks.