AIE photosensitizers in the first NIR window for high-fidelity imaging of cell membranes and photodynamic anticancer therapy

Irreversible damage to the cell membrane is extremely detrimental to the cell. The synthesis of near-infrared (NIR) aggregation-induced emission luminogens (AIEgens) for high-fidelity imaging of cell membranes and the induction of cancer cell necrosis through photo-driving is a desirable option for tumor treatment, but it remains challenging. In this study, a fluorescent probe molecule (ACTP-1) with an amphiphilic structure and AIE properties was designed and prepared. ACTP-1 can effectively bind with 1,2-dioleo-sn-glycerol-3-phosphatecholine or sensitively detect changes in viscosity in a solution and then emit strong red fluorescence in the first NIR window. Due to its specific embedding of the phospholipid bilayer, the rotational motion of the ACTP-1 molecule was suppressed and the luminescence property was activated, resulting in high resolution and excellent photostability for imaging the cell membrane. Furthermore, ACTP-1, which exhibits a high absorption coefficient in the visible region, can rapidly produce reactive oxygen species (ROS) when exposed to white light. Experiments in cell biology have shown that ACTP-1 can effectively disrupt the cytoskeleton through photodynamic therapy (PDT), leading to cell necrosis instead of apoptosis. This highlights its dual functionality as both a reliable imaging agent and a phototherapy agent.