BODIPY as a Photosensitizer for Photodynamic Therapy: Mechanisms, Functionalization, and Future Prospects

Photodynamic therapy (PDT) has the advantages of strong targeting, few side effects, and little damage to normal tissues, which is considered as a high-quality new non-invasive treatment for cancer treatment. Photosensitizer (PSs), molecular oxygen and light are the three main components of PDT. Boron-dipyrromethene (BODIPY) is a widely used organic fluorescent dye, and its core structure is composed of a central boron atom (B) and two pyrrole rings connected by a methylene bridge. The eight active sites on the parent nucleus allow for a variety of functionalization modifications: positions 2,6 are particularly susceptible to halogenation reactions, and cross-coupling, click reactions and Knoevenagel condensation reactions at positions 3,5 are all commonly used structural modifications. As a new photosensitizer, BODIPY has shown broad application prospects in photodynamic therapy due to its excellent optical properties such as strong controllability, excellent light stability, high molar extinction coefficient (up to 120000M-1cm-1), and high fluorescent quantum yields. In this paper, we mainly focus on the strategy of BODPIY self-modification and the design and synthesis of hybrid systems, and finally summarize the advantages and difficulties of BODIPY as a photosensitizer, and looks forward to the future development of BODIPY.