Deep‐red Emitting Ir(III) Complexes as Type‐I Photosensitizers for Lipid Droplets Targeted Photodynamic Therapy

Abstract

AbstractPhotodynamic therapy (PDT) relying on photosensitizer‐induced production of reactive oxygen species (ROS) for killing cancer cells has emerged as a non‐invasive anti‐cancer strategy. Compared with oxygen‐dependent type‐II photosensitizers (PSs) for PDT, the development of intrinsic oxygen‐independent type‐I ones is highly desired but remains a challenge. In this work, two netural Ir(III) complexes that can produce type‐I reactive oxygen species, namely MPhBI−Ir‐BIQ (Ir‐1) and NPhBI−Ir‐BIQ (Ir‐2), were synthesized. Bright deep‐red emitting nanoparticles with moderate particle size are beneficial for imaging‐guided PDT. In in vitro experiments, importantly, the excellent biocompatibility, the targeting of lipid droplets (LDs), and the type‐I ⋅OH and O2⋅− generation promoted effective photodynamic activity. This work will guide the building of type‐I Ir(III) complexes PSs and can provide advantages for potential clinical applications under hypoxic conditions.