Mechanical and Biological Properties of 3D-Printed Magnetic Mesoporous Bioactive Glass Scaffolds via Chitosan/MWCNTs Coating

Abstract

Bone tissue engineering requires scaffolds that combine high bioactivity with sufficient mechanical strength to support tissue regeneration. In this study, a novel strategy was developed to fabricate hierarchical magnetic mesoporous bioactive glass scaffolds reinforced with 7.5 wt Al2O3 nanowires using direct ink writing. To further enhance scaffold performance, the printed structures were coated with chitosan (CS) and chitosan/multi-walled carbon nanotube (CS/MWCNT) nanocomposites. The resulting scaffolds retained their amorphous, mesoporous, and superparamagnetic characteristics while exhibiting a highly interconnected porous architecture. CS coating increased compressive strength by 36.8 +/- 1.2, whereas CS/MWCNT coating produced a substantially greater enhancement of 155.26 +/- 4.4, while maintaining high porosity (> 82). In addition, all scaffolds demonstrated excellent bioactivity, high cell viability (> 85), favorable cell adhesion, and enhanced alkaline phosphatase activity. These findings demonstrate that CS/MWCNT-coated MMBG scaffolds provide an effective combination of mechanical reinforcement and osteogenic potential, offering a promising platform for load-bearing bone tissue engineering applications.