Engineering nanofusiform Iron-doped polydiaminopyridine boost intratumoral penetration for immunogenic cell Death-mediated synergistic Photothermal/Chemo therapy

Photothermal therapy (PTT) featured the advantages of convenient operation, high selectivity and little side effects has been as a non-invasive and promising treatment that converts near infrared light into heat energy through photothermal agents, which however is also trouble with limited penetration depth of near-infrared light, low treatment efficiency and et.al. Considering this situation, we synthesized iron-doped poly (2, 6-diami-nopyridine) nanoparticles (FDAP NPs) with fusiform morphology by one-step oxidative polymerization of Fe3+. To improve therapeutic outcome, the chemotherapeutic drug doxorubicin (DOX) was further decorated on the fusiform surface by hydrophobic interaction to get the expectant FDAP@DOX nanosystem. The collaborative design endowed FDAP@DOX with good photothermal conversion rate, which could convert light energy into heat energy under the irradiation of 808 nm wavelength laser, and then further increased the temperature of the tumor site and leaded to strong immunogenic cell death (ICD) and tumor cell apoptosis. Meanwhile, the increase of temperature also promoted the release of superficial DOX, realizing the synergistic therapeutic modalities of photothermal/chemo therapy and making the tumor weight losing more thorough in 4T1 breast tumor animal model. Thus, this study shows a facile but effective idea for the construction of multimodal therapy-based in-tegrated nanomedicine, and offers a service for the field of photothermal/chemo tumor therapy.