pH/NIR dual-responsive implantable patch for combined photothermal and chemotherapy of tumors

The treatment of malignant solid tumors still faces challenges including the high risk of surgical resection and the severe side effects of chemotherapy. Moreover, existing clinical strategies often fail to meet the treatment needs of patients with inoperable tumors. In this study, a safe and efficient nanofiber patch was designed via electrospinning for combined photothermal-chemotherapy of abdominal tumors. By loading copper sulfide nanoparticles and polydopamine, the patch achieved efficient photothermal effects under safe NIR II laser irradiation. Moreover, the patch exhibited pH/NIR dual-responsive drug release through polydopamine protonation and photothermally enhanced diffusion. With these superior properties, the implantable patch can non-invasively ablate solid tumors via photothermal therapy and eliminate residual cancer cells through controllable chemotherapy, while maintaining low systemic toxicity. Notably, this safe and effective therapeutic strategy exhibited significantly higher tumor apoptosis (68.6%) than the control of only chemotherapy patch (29.3%) or photothermal therapy patch (42.5%). The DPPCP patch + NIR group exhibited dramatically decreased signal intensity, demonstrating superior antitumor efficacy. Moreover, the DPPCP patch enabled 100% survival of nude mice over 90 days. In this work, the patch-mediated combined photothermal-chemotherapy strategy holds promise as an alternative to clinical surgical resection and postoperative chemotherapy, addressing the treatment needs of diverse cancer patients.