Plasma-Enabled Multiscale Coupling of Architecture and Biointerfaces Drives Osteogenesis in 3D-Printed Gyroid Scaffolds

Engineering functional bone scaffolds can be enhanced by integrating biologically instructive nanoscale surface features (e.g., nanotopography and nanoroughness), micro-scale geometric cues (e.g., curvature and porosity), and macro-scale mechanical properties (e.g., bulk stiffness); however, these length scales are often optimized independently. Here, we present a multiscale design framework combining additive manufacturing of triply periodic minimal surface (TPMS) gyroid scaffolds with plasma-assisted nanoscale surface engineering to regulate osteogenesis. Controlled variation in strut thickness generates distinct architectural regimes with coupled changes in curvature, porosity, and compressive modulus, recapitulating key aspects of trabecular bone mechanics. Micro-computed tomography confirms trabecular bone-like features, while finite element modeling and compression testing reveal that thinner architectures (0.6 mm) exhibit curvature-preserving geometry and distributed stress profiles favorable for cellular interaction. A low-temperature plasma electroless reduction (PER) strategy enables controlled silver nanoparticle deposition, while polydopamine-mediated adhesion ensures uniform and cytocompatible coatings. Notably, PDA-AgNP-functionalized 0.6 mm scaffolds significantly outperform unmodified and AgNP-only groups, exhibiting enhanced cytoskeletal organization, stress fiber formation, matrix mineralization, and osteogenic gene expression. These findings demonstrate that coupling nanoscale biointerface features with micro- and macro-scale architecture produces a synergistic enhancement in osteogenesis, providing a design framework for functional bone scaffolds.