Connections between Metallic Nanoparticles and Chlorin e6-An Overview of Physicochemical and Biological Properties and Prospective Medical Applications

Photodynamic therapy is a non-invasive method of treatment for both neoplastic diseases and miscellaneous non-cancerous illnesses. It is complementary and, in some way, counter to various traditional treatment techniques, including chemotherapy, radiotherapy, and surgery. To date, various types of nanoparticles and compounds, including those belonging to the porphyrinoid group, have been researched in terms of future applications in technology and medicine. Among them, chlorins and their conjugates, combined with metallic nanoparticles, deserve special attention due to their enhanced photodynamic activity and the accompanied synergic photothermal effect. Many hybrid nanosystems reveal increased cellular uptake and improved stability and, therefore, can be applied in enhanced MRI imaging, as well as in targeting therapy. This review is focused on conjugates of metallic nanoparticles and chlorins, having in mind prospective applications as photosensitizers in multimodal neoplastic therapy, as well as tumor diagnosis.