Near Infrared-Absorbing Nanoparticle-Mediated Endovascular Photothermal Precision Embolization of Tumor Feeding Vessels for Starvation Treatment

Photothermal therapy has attracted enormous attention as an efficient treatment modality in cancer ablation but still encounters a major bottleneck due to the limited penetration depth of light inside tissues. To overcome the challenge of deep tissue penetration, we present a strategy of endovascular photothermal precision embolization (EPPE), which employs an endovascular optical fiber to induce local embolization only in the entrance of feeding vessels through photothermal heating for the purpose of fully blocking the blood supply of the whole tumor. In EPPE, we apply a highly efficient and biocompatible photothermal agent, i.e., near-infrared (NIR)-light-absorbing diketopyrrolopyrrole-dithiophene-based nanoparticle, which exhibits a high cell-killing efficacy at a concentration of 200 μg/mL using 808 nm laser irradiation of 0.5 W/cm2 within 5 min in both 2D cell culture and a 3D tumor spheroid model. We verify the feasibility of EPPE in an ex vivo organ-structured recellularized liver model and further confirm the in vivo efficacy of the photothermal treatment in a rat liver model. The photothermal treatment combined with the embolization effect holds promise to serve as an effective starvation therapy to treat tumors of varying sizes and locations.