Controlled Synthesis Of Hollow Structure AgBiS₂ And Its Application In Tumor Theranostic

With the rise of cancer incidence,traditional treatment methods such as surgical resection,chemotherapy and radiotherapy can no longer meet the actual needs.Among them,photothermal therapy?PTT?based on cell thermal stress response to kill tumors has attracted great attention.However,PTT usually requires the temperature in the central area of the tumor to reach 50 ^oC,and a temperature gradient will be formed,so that the edge of the tumor achieves the therapy temperature.Therefore,enhancing the utilization of photothermal materials for near-infrared light?NIR?and improving the photothermal conversion efficiency are essential for PTT reagents.In this dissertation,a ternary alloyed silver bismuth sulfide?AgBiS₂?has been synthesized to enhance photothermal therapy by enhancing the photothermal properties of sulfides,which can be used to build a photothermal-based multifunctional tumor treatment platform.The main topics of this thesis are as follows:Firstly,the hollow structure AgBiS₂ microspheres were prepared using a simple polyol process,which exhibited a broad and strong near-infrared absorption and higher photothermal conversion efficacy.Secondly,based on the advantages of the hollow structure,a drug delivery system was built adopting the doxorubicin?DOX?as the model.In vitro tests demonstrated that the drug was successfully loaded and controllable released with NIR responsiveness.Thirdly,the as-prepared AgBiS₂ illustrated tumor microenvironment?TME?responsive toxicity,which could interact with overexpressed H₂O₂ in the tumor area to produce highly toxic active oxygen species?ROS?.In addition,the existence of Bi element enables the nanoplatform with CT imaging function owning to its high X-ray attenuation performance.Therefore,a hollow structured AgBiS₂was fabricated as a nanoplatform which could perform PTI/PAI/CT triple imaging guided photothermal therapy and improved ROS generation with tumor microenvironment response.