Facile construction of gold- and BODIPY-coordinated liposomal nanocomplexes for enhanced photothermal therapy of cancer

Photothermal therapy (PTT) has attracted extensive attention in cancer treatment because of its advantages of non-invasive and few side effects. Gold nanoparticles and boron-fluorine-dipyrrole (BODIPY) dye have been used as photothermal agents (PTAs), but they have problems such as easy aggregation, poor water solubility and low photothermal conversion efficiency. In this work, we used conventional liposomes for in situ generation of small gold nanoparticles and sequentially loading BODIPY to overcome the drawbacks of the two PTAs and simultaneously realize enhanced PTT. Gold- and BODIPY-coordinated liposomal nanocomplexes LAB with small gold nanoparticles adsorbed on the surface and BODIPY entrapped inside showed uniform size of about 100 nm with good stability. LAB demonstrated laser-responsive drug release property, good cellular uptake efficiency and tumor accumulation ability. After laser irradiation, LAB can exert enhanced PTT in cancer cell lines by reducing mitochondrial membrane potential and increase intracellular reactive oxygen species level to promote cell apoptosis. In tumor-bearing mice, LAB showed fantastic tumor inhibition effect with good biosafety. This work provides a convenient method to develop PTA combinations for enhanced PTT, which could lay the foundation for the green construction of new PTAs for PTT by employing clinically used formulations and PTAs.