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.