Artificial Periosteum with Balanced Antibacterial and Osteogenic Properties Regulated by NIR Radiation and Strontium Doping

Infected bone defects arising from trauma or tumour resection pose significant challenges in orthopaedic reconstruction. To address these challenges, silver nanorods (AgNRs) were encapsulated within Sr-doped mesoporous bioactive glass (BG@Sr) and incorporated into polylactic acid (PLA)/ gelatine fibres via a ‘one-pot’ electrospinning technique to prepare artificial periosteum (PAR-Sr), which enables photothermally triggered antibacterial Ag⁺ release and sustained osteogenic Sr²⁺ delivery. Sr doping-generated negatively charged Si–O⁻ and nonbridging oxygen (NBO) species effectively modulate Ag⁺ release kinetics to prevent burst effects. PAR-Sr periosteum replicates the mechanical profile of the native human periosteum, while retaining critical flexibility, lightweight properties, and physiological stretchability. In vitro studies confirmed that PAR-Sr achieved a photothermal conversion efficiency of 33.8% and demonstrated significant antibacterial efficacy against both planktonic and biofilm forms (> 99%) under near infrared (NIR) irradiation. Furthermore, PAR-Sr demonstrates exceptional biocompatibility and osteogenic potential, as evidenced by its ability to upregulate osteogenic-related gene expression, increase alkaline phosphatase (ALP) activity, and promote extracellular matrix (ECM) mineralization. In a rat cranial defect infection model, the PAR-Sr periosteum exhibited remarkable osseointegration capacity under NIR irradiation, while simultaneously reducing postoperative inflammatory responses. This periosteum represents a promising therapeutic strategy for preventing implant-associated infections and enhancing bone integration in orthopaedic applications.