| Owing to high selectivity and minimal invasiveness, photothermal therapy has attracted extensive interestis as a powerful technique for cancer treatment. Photothermal therapy is a approach that employs heat converted by photothermal ablation agents from light absorption to‘‘burn’’ target cancer cells. Photothermal agents is generally indispensable in order to achieve targeted and efficient photothermal ablation of cancer cells. Therefore, the development of photothermal agents is of crucial importance for the application of photothermal therapy(PTT).With the help of medical imaging, people can identify the location and size of tumors and the presence of photo-absorbing agents before therapy, and monitor the treatment procedure in real-time during therapy, and assess the effectiveness after therapy. The imaging approaches involve photoacoustic tomography(PAT), positron emission tomography(PET), magnetic resonance imaging(MRI), X-ray computed tomography(CT) and so on. Despite numerous imaging modalities have been developed, the selection of a single appropriate imaging modality for precisely diagnosing is still a conundrum because each imaging modality has its own advantages and limitations. The appearance of multimodal imaging solved the problem. Multimodal imaging combines different modalities together to provide complementary information and achieve synergistic advantages over any single modality alone. One major challenge of multimodal imaging is to develop an efficient platform to load various components with individual contrast properties together whilst maintaining compact size, good biocompatibility and targeting capability.The main content of this paper is to explore the synthesis of inorganic semiconductor nanoparticles which can be applied for multi-modal imaging, especially for CT imaging,photoacoustic imaging and photothermal therapy. The first introduction chapter can be divided into two blocks, one of which introduces the inorganic nano-probes for medical imaging and cancer treatment, the second block is to highlight the bismuth sulfide and Prussian blue nanomaterials. In the second chapter, we fabricated the bismuth sulfide by a new experimental scheme. Different from the traditional synthetic methods, which is using an organic phase as solvent, the bismuth sulfide nanospheres are synthesized in the aqueous phase with polyvinylpyrrolidone as the surface capping agent by direct one-step synthesis. In addition, we explore the structural properties of bismuth sulfide and prove its potential to be applied to photoacoustic imaging and photothermal therapy..The third chapter introduces a optimized experimental program continuing the direct synthesis in anaqueous phase, by which the synthetic bismuth sulfide has better near-infrared absorption.Polyethylene glycol was used as the surface capping agent in place of polyvinylpyrrolidone. The bismuth sulfide nanoparticles have the characteristic of superior NIR photothermal conversion efficiency and have potential as therapeutic agents and photothermal photoacoustic imaging contrast agents The fourth chapter is a synthesis of Prussian blue compound, bismuth-doped Prussian blue nanosheets. Prussian blue is widely used in photoacoustic imaging and photothermal therapeuty because of its good properties such as low toxicity, good near-infrared absorption.Bismuth has also been used clinically for many years as a drug for treating stomach. Besides,bismuth is a good CT imaging contrast agents. The bismuth-doped Prussian blue nanosheets synthesized by one-step method can be applied for X-ray computed tomography, photoacoustic tomography and photothermal therapy. |
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