A nanocomposite competent to overcome cascade drug resistance in ovarian cancer mitochondria dysfunction and NO gas synergistic therapy.

Ovarian cancer (OC) is one of the most common and recurring malignancies in gynecology. Patients with relapsed OC always develop "cascade drug resistance" (CDR) under repeated chemotherapy, leading to subsequent failure of chemotherapy. To overcome this challenge, amphiphiles (P1) carrying a nitric oxide (NO) donor (Isosorbide 5-mononitrate, ISMN) and high-density disulfide are synthesized for encapsulating mitochondria-targeted tetravalent platinum prodrug (TPt) to construct a nanocomposite (INP@TPt). Mechanism studies indicated that INP@TPt significantly inhibited drug-resistant cells by increasing cellular uptake and mitochondrial accumulation of platinum, depleting glutathione, and preventing apoptosis escape through generating highly toxic peroxynitrite anion (ONOO). To better replicate the microenvironmental and histological characteristics of the drug resistant primary tumor, an OC patient-derived tumor xenograft (PDX) model in BALB/c nude mice was established. INP@TPt showed the best therapeutic effects in the PDX model. The corresponding tumor tissues contained high ONOO levels, which were attributed to the simultaneous release of O and NO in tumor tissues. Taken together, INP@TPt-based systematic strategy showed considerable potential and satisfactory biocompatibility in overcoming platinum CDR, providing practical applications for ovarian therapy.