Polypyrrole-based nanotheranostic agent for MRI guided photothermal-chemodynamic synergistic cancer therapy

Polypyrrole (PPy) nanoparticles have been widely studied in tumor photothermal therapy (PTT) for their significant photostability, good biocompatibility, and excellent photothermal performance. Herein, we report bovine serum albumin (BSA) stabilized PPy that were mineralized by MnO₂ nanozyme on the surface (PPy@BSA-MnO₂) to achieve synergistic photothermal and chemodynamic therapy (CDT) for breast cancer. In this multifunctional nanoplatform, the surface-loaded MnO₂ undergoes a redox reaction with glutathione (GSH) to generate glutathione disulfide (GSSG) and Mn²⁺. Then, Mn²⁺ can convert H₂O₂ into a highly cytotoxic ˙OH to achieve chemodynamic therapy (CDT) and possess good magnetic resonance (MR) T₁-weighted imaging capabilities to realize contrast imaging of the 4T1 tumor-bearing mouse models. In addition, PPy nanoparticles can efficiently convert near-infrared light energy into heat and achieve PTT. Most importantly, PPy@BSA-MnO₂ nanoprobes have excellent in vitro 4T1 cell-killing effect and in vivo tumor-suppressive properties. The acute toxicity assessment results indicate that PPy@BSA-MnO₂ nanoprobes have good biological safety. Therefore, the as-prepared multifunctional PPy@BSA-MnO₂ nanoprobes possess excellent performance to promote MRI-guided PTT/CDT synergistic therapy for breast cancer treatment and have extensive clinical transformation and application prospects.