Study on the preparation of iron-incorporated tannin films and their dual synergistic photothermal-Fenton reaction for osteosarcoma suppression.

The intelligent responsive drug delivery systems show great promise for precision cancer therapy. However, despite the development of numerous antitumor strategies based on drug delivery platforms, their therapeutic efficacy remains generally limited. In this study, we constructed a platform for synergistic photothermal (PTT) and Chemical kinetics therapy (CDT) to inhibit osteosarcoma. For the first time, a composite film of Fe3O4 and tannic (TA) was successfully fabricated using a combined approach of pulsed laser deposition (PLD) and low-energy electron beam deposition (EBD). The coordination between TA and Fe ions formed a stable Fe-TA network structure, significantly enhancing the mechanical stability and photothermal conversion performance of the film. The incorporation of Fe not only imparts a photothermally enhanced local heating effect but also effectively accelerates the kinetics of the intracellular Fenton reaction, boosting the generation efficiency of ·OH radicals. Both electron paramagnetic resonance (EPR) and ROS fluorescence staining confirmed that the system induces intense hydroxyl radical release under NIR irradiation, thereby promoting apoptosis. In vitro cellular experiments and in vivo animal studies further demonstrated that this photothermal-Fenton synergistic effect significantly improved therapeutic outcomes, exhibiting excellent antitumor performance. Therefore, the FT film not only serves as structurally stable and highly responsive photothermal conversion materials but also possesses temperature-controlled release and ROS regulatory capabilities, highlighting its broad application prospects in multimodal synergistic tumor therapy, such as combined PTT and Fenton reaction treatment.