Bifunctional 3D-printed PEEK scaffolds incorporating hydrogel-encapsulated magnesium-quinone nanosheets for antibacterial activity and mandibular bone regeneration

Infectious mandibular bone defects present significant clinical challenges due to the complex pathological microenvironment, risk of persistent bacterial colonization, and insufficient bone regeneration. Poly (ether ketone) (PEEK) is considered a promising alternative to metallic implants owing to its bone-mimetic mechanical properties; however, its intrinsic hydrophobicity and bioinertness hinder osseointegration and functional recovery. Here, a bifunctional 3D-printed porous PEEK scaffold coated with an alginate hydrogel encapsulating magnesium-aloe emodin (MgAe) nanosheets (AP@MgAe) was developed to achieve simultaneous antibacterial and osteogenic functions. MgAe nanosheets were synthesized via metal-quinone coordination-driven self-assembly, enabling the co-delivery of bioactive Mg²⁺ and aloe emodin in a pH-responsive and sustained-release manner within the hydrogel coating. <i>In vitro</i>, AP@MgAe scaffolds exhibited potent antibacterial activity against <i>S. aureus</i>, excellent cytocompatibility, and enhanced osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs). <i>In vivo</i>, AP@MgAe scaffolds effectively suppressed infection, attenuated inflammation, and promoted bone formation and osseointegration in a rat model of infectious mandibular bone defects. Collectively, this work introduces a novel metal-quinone framework-integrated 3D-printed PEEK platform, offering a clinically promising, antibiotic-free, and bifunctional strategy for treating infection-associated bone defects.