Isoindigo nanoparticles for photoacoustic imaging-guided tumor photothermal therapy

The key factor in photothermal therapy lies in the selection of photothermal agents. Traditional photothermal agents generally have problems such as poor photothermal stability and low photothermal conversion efficiency. Herein, we have designed and synthesized an isoindigo (IID) dye. We used isoindigo as the molecular center and introduced common triphenylamine and methoxy groups as rotors. In order to improve the photothermal stability and tumor targeting ability, we encapsulated IID into nanoparticles. As a result, the nanoparticles exhibited high photothermal stability and photothermal conversion efficiency (67%) upon 635 nm laser irradiation. Thus, the nanoparticles demonstrated a significant inhibitory effect on live tumors in photothermal therapy guided by photoacoustic imaging and provided a viable strategy to overcome the treatment challenges.