Amplified ferroptosis and immunomodulation triggered by NIR-II photothermal-controllable CRISPR/Cas9 nanoplatform to treat osteosarcoma and prevent postsurgical implant-associated infections.

Abstract

Ferroptosis has been proven as a promising therapeutic approach with immunomodulatory effect; however, intracellular antioxidant system maintains redox balance and diminishes its efficacy. Nuclear factor erythroid 2-related factor 2 (Nrf2) is identified as a central transcription factor for regulating oxidative homeostasis. Herein, we have developed a thermal-controllable genome-editing nanoplatform BF/pHCN. Specifically, a CRISPR/Cas9 plasmid with an upstream HSP70 promoter sequence (HSP70-Cas9-sgNrf2, named pHCN) was constructed. Subsequent Fe(II) and pHCN were co-loaded into organic small-molecule BTP with near infrared II (NIR-II) absorption and coated with DSPE-mPEG₂₀₀₀. The generated BF/pHCN (BTP@Fe/pHCN) could be internalized within osteosarcoma cells. Subsequent NIR-II laser-triggered hyperthermia at 42 °C activated the HSP70 promoter and facilitated the precise inhibition targeting Nrf2 genomic sequences while promoting Fe(II) release, ultimately disrupting oxidative stress states. Moreover, the amplified ferroptosis fully triggered immunogenic cell death, thus reprogramming macrophages, promoting maturation of dendritic cells, and activating cellular antitumoral immunity. Additionally, BF/pHCN exhibited direct bactericidal activity against planktonic bacteria, and effectively eliminated intracellular bacteria through iron metabolic disorders strategy targeting macrophages, thereby initiating adaptive antimicrobial immunity. Overall, our NIR-II thermal-controllable genome-editing nanoplatform BF/pHCN exhibits remarkable antitumoral properties alongside robust antiinfection and immunomodulation, providing feasible strategies toward effective management of osteosarcoma, and preventing postsurgical implant-associated infections.