Improved bacteriostatic and in vitro cell activity of 3D printed silica-doped HAp scaffolds with tunable mechanical response and mass transport characteristic

Bone tissue defects caused by trauma, aging, or tumors necessitate advanced regenerative strategies. This study investigates silica-doped hydroxyapatite (HAp) scaffolds with Gyroid triply periodic minimal surface (TPMS) structures fabricated via digital light processing (DLP), combined with femtosecond laser (FS) surface modification to enhance mechanical, bioactive, and antibacterial properties. Finite element analysis (FEA) and computational fluid dynamics (CFD) revealed that the Gyroid structure exhibited superior mechanical isotropy (Zener ratio ≈ 1) and permeability (34.52×10 -9 m 2 ) compared to Schwarz and Fluorite lattices, facilitating efficient nutrient transport and cell migration. FS ablation induced hierarchical micro/nanostructures on silica-doped HAp (FSH), increasing surface area (121 ± 1.03 μm 2 ) and hydrophilicity (contact angle: 27.7°), which enhanced protein adsorption (88.0 ± 20.3 μg/mL) and osteoblast adhesion/proliferation. In vitro tests demonstrated FSH’s antibacterial efficacy against E. coli (82.83% inhibition) and robust bioactivity via hydroxyapatite layer formation in simulated body fluid. These findings highlight the potential of DLP-printed Gyroid scaffolds with FS-modified surfaces as a promising platform for bone tissue engineering, offering tailored mechanical properties, enhanced mass transfer, and multifunctional biological responses.