Design and Construction of Photosensitizers for Photodynamic Therapy of Tumor

In this chapter, we describe the therapeutic principles of photodynamic therapy (PDT) and its advantages and disadvantages compared with conventional treatments. Then, the influencing factors of PDT efficiency are discussed. To improve the efficiency of PDT, it is crucial to develop and optimize photosensitizers. Subsequently, we introduce various types of photosensitizers in sequence, including organic molecules, metal complexes, organic frameworks, carbon nanomaterials, silicon-based materials, simple substances, metal oxides, and lanthanide upconversion nanoparticles-based photosensitizers. Notable recent studies are selected to illustrate the design concept and logic, as well as key mechanisms of tumor treatment. We present guidelines and examples of developed photosensitizers to aid future studies in photosensitizer development. These guidelines address issues such as low yield of reactive oxygen species, insufficient tumor accumulation of photosensitizer, shallow penetration depth of light, and the inability of single PDT to effectively inhibit tumor growth. Finally, recommendations and insights for the advancement of photosensitizers are prompted.