Hierarchical bone scaffolds with integrated trabecular topology and lacuno-canalicular connectivity modulate fluid...

The hierarchical structure of bone governs both mechanical behavior and mechanobiological signaling, yet most Bone Tissue Engineering (BTE) scaffolds reproduce only meso-scale porosity while neglecting the Lacuno-Canalicular Network (LCN), a key regulator of interstitial fluid flow. Here, we present a multi-scale bio-inspired scaffold integrating synchrotron μ-CT-derived trabecular architecture with a computationally engineered LCN-like micro-porosity. Two micro-network topologies, Regular and Canalicular-like, were fabricated via two-photon polymerization using IP-VISIO, here applied for the first time in a BTE context. Computational fluid dynamics revealed topology-dependent transport behavior: the Canalicular-like architecture exhibited >40% higher permeability and more homogeneous wall shear stress distributions within osteogenic-relevant ranges compared to the Regular design. Human bone marrow-derived mesenchymal stromal cells were cultured onto scaffolds under static conditions, showing cell attachment, osteogenic gene expression, and mineralized matrix deposition in both designs, assessed by SEM, RT-qPCR and Alizarin Red S staining. Synchrotron μ-CT showed mineral deposition throughout both trabecular regions and the engineered micro-network, with a more uniform spatial distribution in the Canalicular-like scaffold. Overall, this work proposes a multi-scale design framework and identifies LCN-inspired micro-architecture as a promising design variable for hierarchical bone scaffolds, influencing predicted fluid-dynamic behavior and supporting osteogenic culture.