An Ion-Based Strategy Toward Synergistic Surface Functionalization Combining the Osteogenic Properties and NIR-Mediated Antibacterial Activity of PEEK.

Persistent implant-associated infections critically compromise the longevity and success of orthopedic prostheses. Herein, we present a facile surface-engineering strategy to construct a multifunctional PEEK-based implant by introducing manganese-chelated polydopamine (Mn@p) and mesoporous bioactive glass nanoparticles (MBGNs) onto sulfonated PEEK (SPEEK). The resulting Mn@p/MBG-SPEEK exhibits a hierarchically porous three-dimensional architecture with markedly enhanced hydrophilicity and surface roughness. This tailored interface shows in vitro bioactivity and cytocompatibility, significantly promoting the osteogenic differentiation of MC3T3-E1 cells through the activation of PI3K/Akt/mTOR and AP-1 signaling pathways, as evidenced by the upregulation of ALP, OCN, OPN, and Runx2 expression. Meanwhile, the pro-angiogenic potential of Mn@p/MBG-SPEEK is supported by the upregulation of VEGF and CD31 in HUVECs and enhanced capillary-like network formation. Notably, Mn@p/MBG-SPEEK demonstrates efficient light-to-heat conversion and potent antibacterial efficacy against Staphylococcus aureus under near-infrared (NIR) irradiation. Density functional theory (DFT) calculations further reveal that Mn chelation narrows the HOMO-LUMO energy gap and facilitates charge separation, thereby amplifying photothermal and ROS-mediated antibacterial effects. Collectively, this study establishes a versatile and scalable route to enhance the biological performance of PEEK implants, offering a conceptual framework for integrating ion-assisted therapy with phototherapy toward next-generation bioactive and infection-resistant orthopedic materials.