Dual‐Functional 3D‐Printed Porous Titanium–Hydrogel Composite Scaffold With Mg 2+ and ZIF‐8 Release for Enhanced Bone Regeneration and Bacterial Inhibition

3D‐printed titanium implants are extensively utilized in bone reconstruction. However, their bioinertness and lack of antibacterial activity increase risks of aseptic loosening and implant‐associated infection—the primary causes of implant failure. To address these limitations, we developed a dual‐functional 3D‐printed porous titanium–hydrogel composite scaffold to enhance the osteogenic and antibacterial capacities of titanium. This composite scaffold was fabricated by integrating quaternized chitosan (QCS)/aldehyde‐terminated Pluronic F127 (PF127‐CHO) hydrogel loaded with magnesium ions (Mg 2+ ) and zeolitic imidazolate framework‐8 (ZIF‐8) into polydopamine‐coated 3D‐printed porous titanium scaffold. The composite scaffold exhibited sustained and controlled release of Mg 2+ and ZIF‐8 with enhanced binding strength at titanium–hydrogel interface. In vitro experiments demonstrated that the composite scaffold possessed favorable biocompatibility, promoted the adhesion and proliferation of MC3T3‐E1 cells, and facilitated their osteogenic differentiation through synergistic effect of Mg 2+ and ZIF‐8. Furthermore, it also inhibited bacterial growth via synergistic action of QCS/PF127‐CHO hydrogel and ZIF‐8. In vivo experiments confirmed enhanced bone ingrowth into the composite scaffold and its effective antibacterial activity. In summary, this composite scaffold provides a promising strategy to simultaneously improve the osteogenic and antibacterial capacities of titanium implants.