Topology-guided multidimensional mechanics–transport–bioactivity mapping and physiological matching of porous bone scaffolds

The design of porous bone scaffolds involves balancing the competing demands of mechanical stability and biological functionality. Sufficient stiffness is essential for providing immediate load-bearing capacity after implantation, while long-term bone regeneration requires adequate permeability and flow-induced mechanobiological stimulation. This study systematically assesses the multidimensional performance of 46 representative scaffold architectures, including truss lattices, triply periodic minimal surface (TPMS) structures, and stochastic architectures, within a biologically relevant porosity range of 60% to 80%. Through finite element simulations coupled with Gibson–Ashby scaling analysis, we show that continuous sheet-based topologies exhibit stretching-dominated deformation, significantly enhancing structural efficiency compared to bending-dominated strut and skeletal lattices. Further, three-dimensional elastic tensor analysis reveals substantial spatial anisotropy and off-axis shear vulnerabilities in highly directional lattice systems, whereas continuous sheet and stochastic architectures maintain near-isotropic stiffness distributions and better multiaxial load resistance. Hydrodynamic simulations uncover a critical transport–stimulation trade-off. While orthogonally open lattices maximize intrinsic permeability, their streamlined flow channels generate weak wall shear stress, potentially leading to hydrodynamically under-stimulated regions. In contrast, the bicontinuous curvature of sheet-based architectures modulates local flow patterns, increasing specific surface area and enhancing mechanobiological stimulation. By integrating mechanical, transport, and spatial characteristics, we establish a physiologically motivated tripartite performance map, classifying scaffold architectures into load-bearing prioritized, transport-prioritized, and biomimetic balanced regimes. More importantly, a physiological matching index is introduced to quantitatively assess scaffold suitability for various clinical scenarios. This multidimensional design framework provides a topology-guided foundation for the development of next-generation orthopedic implants tailored to specific physiological needs.