Molecularly engineered BODIPY photosensitizers for combined cancer phototherapy and immunotherapy

BODIPY-based photosensitizers have attracted great interest in cancer phototherapy and immunotherapy due to their tunable structures, excellent photostability, and high molar extinction coefficients. However, conventional BODIPY dyes have inherent limitations, such as poor water solubility, shallow tissue penetration, oxygen dependence, and insufficient single-modality efficacy. To address these, recent studies have used molecular engineering (ring fusion, electronic modulation, supramolecular assembly, metal coordination) to enhance reactive oxygen species generation and photothermal conversion. Smart delivery systems with microenvironment responsiveness further enable tumor targeting and microenvironment remodeling. Importantly, BODIPY-mediated phototherapy combined with immunotherapeutic strategies (immune checkpoint blockade, pyroptosis/cuproptosis induction, cGAS-STING activation, etc.) achieves synergistic antitumor effects, transforming localized tumor ablation into systemic immunity. This review summarizes recent progress in molecularly engineered BODIPY photosensitizers, from molecular optimization and smart delivery to immune synergy, and discusses current challenges and future directions to promote their clinical translation.