SWIR-responsive SeTe nanoparticles integrate antibacterial activity and selenoprotein-associated redox regulation for infected bone defect repair.

Infected bone defects remain a critical clinical challenge due to the coexistence of persistent bacterial infection, excessive inflammation, and impaired bone regeneration. The development of nanoparticle-based phototherapy capable of simultaneously addressing these issues is therefore of great significance. Here, selenium-tellurium (SeTe) nanoparticles via a novel sputtering and exfoliation process were developed. These agents showed strong short-wave infrared (SWIR) photothermal/photoelectric responses, alongside excellent physicochemical stability and biocompatibility, making them promising active phototherapeutic candidates. SeTe inhibited bacterial growth and biofilms under SWIR while reducing reactive oxygen species and suppressing inflammation-related cytokines. Notably, SeTe upregulated selenoproteins like GPX4 and GPX1, enhancing antioxidant capacity and redox balance. SeTe also promoted osteogenic differentiation via increased alkaline phosphatase activity, mineralization, and osteogenic gene/protein expression. In vivo, SeTe combined with SWIR significantly improved infected bone defect repair-reducing bacteria, boosting new bone formation, and restoring bone microarchitecture. Histology and immunohistochemistry showed reduced inflammation, along with elevated osteogenic and antioxidant markers. This multifunctional SeTe-based system integrates antibacterial, anti-inflammatory, and osteogenic properties, offering a promising approach for treating infected bone defects and advancing biomaterial design for complex tissue regeneration.