Mesoporous bioactive glasses (MBGs) are a promising class of bioceramics for bone repair. In this study, a novel MBG nanopowder (5 mol % Mg, 5 mol % Zr; ∼700 m2/g surface area, ∼20 nm particle size) synthesized via the sol-gel method was used to fabricate 3D-printed polycaprolactone (PCL)-based scaffolds, with 60–70 wt % MBG content, for bone tissue engineering (BTE). For comparison, scaffolds with and without Mg and Zr ions were produced using fused deposition modeling (FDM). The effects of MBG content and ion composition on scaffold properties were assessed through compressive testing, biodegradation, bioactivity, ion release, and osteogenic assays. Scaffolds containing 65 wt % MBG with Mg and Zr ions exhibited enhanced mechanical properties (compressive strength of ∼17 MPa), controlled biodegradability, and superior bioactivity, including apatite formation and ion dissolution. In vitro studies using MG-63 osteoblast-like cells demonstrated improved biocompatibility, as shown by enhanced cell viability, adhesion, and proliferation. These findings underscore the potential of the 3D-printed PCL+65 %MBG scaffold as a bioactive, load-bearing material for advanced BTE applications. © 2025 The Authors
