Drug‐Loaded Mitochondrial Targeted Nanoparticles for Tumor Imaging and PDT/PTT Combined Chemotherapy in Muscle‐Invasive Bladder Cancer

Abstract Neoadjuvant chemotherapy combined with radical cystectomy is the standard treatment for muscle‐invasive bladder cancer (MIBC). While cisplatin‐based regimens reduce postoperative recurrence, their severe toxicity often limits clinical application. Moreover, the need for urinary diversion after radical cystectomy significantly impacts quality of life, leading to reluctance toward surgery. Therefore, developing tumor‐targeted therapies and alternative treatment strategies for MIBC is of great clinical significance. In this study, the IR780 iodide multifunctional dye is conjugated to alginate polysaccharide and developed a novel cisplatin‐loaded nanoparticle. Then, the tumor targeting and antitumor effects of the nanoparticles are evaluated in vitro and in vivo. The results show that the nanoparticles have sufficient drug loading, enhanced tumor targeting, and good photothermal effect. Furthermore, they shows potential for tumor imaging and diagnostic applications in a mouse model of MIBC. This study proposes a potentially effective treatment for MIBC by combining near‐infrared localized phototherapy with systemic chemotherapy to eliminate malignant tissue.