Near‐Infrared Switch‐Driven Macrophage Dynamically Reprogramming for Anti‐Infection and Tissue Healing on Polyetheretherketone Implants

Abstract High infection risk and poor tissue integration are major causes of percutaneous implant failure. Immune reprogramming is a promising strategy, but current implants rely predominantly on passive and static modulation of macrophages. Dynamically reprogramming macrophages based on physiological states to switch between antibacterial and tissue‐healing functions remains a challenge. Here, a novel polyetheretherketone (PEEK) surface is developed sequentially modified through sulfonation, hydrogen plasma immersion ion implantation (H‐PIII), and magnesium plasma immersion ion implantation (Mg‐PIII) to fabricate a Mg‐H‐SPEEK composite with a graphene‐like matrix embedded with MgO. This film simultaneously enables sustained Mg ² ⁺ release with near‐infrared (NIR) photothermal responsiveness for on‐demand immunomodulation. Under normal conditions, Mg ² ⁺ released from Mg‐H‐SPEEK can promote macrophage reprogramming toward the M2 phenotype through the TNF, JAK‐STAT, NF‐κB, and IL‐17 pathways to accelerate soft tissue repair. Upon NIR light exposure, photothermal stimulation enhances the expression of the Traf1 in macrophages via the TNF, FoxO, and JAK‐STAT signaling pathways to drive M1 reprogramming for bacterial phagocytosis. The dual‐mode system synergizes hyperthermia and immune phagocytosis for infection resistance while preserving pro‐healing functions, offering a smart strategy for percutaneous implants.