Scaffold Material-Architecture Design Rules Linking Mechanics and Early Osteogenesis in PCL/β-TCP Grid, Honeycomb, and Gyroid Lattices.

Clinicians still lack truly patient-specific bone scaffolds that simultaneously match defect mechanics and provide early osteogenic cues because current constructs offer limited control over both lattice architecture and multiscale topography. Here, we compare seven scaffold systemsPCL nanofibrous membranes made by Direct Electrospin Writing (DEW), 3D-printed PCL grid, honeycomb and gyroid lattices, and commercial Ossiform β-TCP grid, honeycomb, and gyroid scaffoldsto derive material-architecture design rules that couple mechanics with early osteogenic response. Scaffolds were fabricated by fused-filament 3D printing or DEW, imaged by SEM/confocal microscopy, mechanically tested in monotonic tension to obtain apparent Young's modulus and structural stiffness, and cultured with MG63 cells for 7 days to assess cytocompatibility by MTT and morphology. β-TCP scaffolds showed the highest modulus but elastic-brittle failure; printed PCL lattices exhibited tunable viscoelastic behavior, with grid providing the greatest stiffness, honeycomb trading stiffness for energy absorption, and gyroid homogenizing strain. Despite being the most compliant, PCL DEW nanofibers produced the highest early proliferation and most elongated cells, consistent with ECM-mimetic nanotopography, while PCL-gyroid and β-TCP-gyroid supported enhanced spreading and 3D colonization due to continuous curvature and microrough, osteoconductive surfaces. These results indicate that early osteogenic behavior is governed by joint effects of nanoscale topography, curvature-driven strain distribution, and ceramic chemistry rather than stiffness alone. The study is limited to 7-day in vitro responses and air-tested mechanics; future work will examine long-term differentiation and mineralization, hydrated/degrading mechanics, and hybrid PCL/β-TCP architectures to translate these design rules toward point-of-care, patient-specific bone repair.