Large Animal Models to Study the Applications of Photodynamic Therapy

Photodynamic therapy (PDT) is a minimally invasive therapeutic modality that utilizes photosensitizers, specific wavelengths of light, and oxygen to generate reactive oxygen species (ROS) for the treatment of a wide range of diseases with great potential. However, the development of PDT is limited by the selectivity of photosensitizers, the depth of light penetration, and the potential damage to normal tissues. Current trends in PDT are focused on the development of novel photosensitizers, the application of nanotechnology, and the combination with other therapeutic strategies. Animal models play a crucial role in PDT research; they are not only used to validate the efficacy and safety of PDT, but also help to optimize therapeutic parameters and provide insight into the mechanism of action of PDT. This review summarizes the use of PDT in different disease models, including cancer, infection, and nontraditional indications, and highlights the importance of large animal models in PDT research, which provide experimental platforms that more closely resemble human physiological and pathological states. In addition, the use of rabbit, pig, dog, and non-human primate models in PDT is highlighted, and how these models can help us understand the mechanisms of PDT, optimize therapeutic regimens, and evaluate clinical outcomes. We aim to provide valuable insights for future studies of PDT and emphasize the importance of selecting appropriate animal models in preclinical studies.