Phosphorus Phthalocyanine-Based NIR-II Nanoparticles for Photoacoustic Imaging and Photothermal Therapy of Thrombus.

A thrombus blocks blood flow, triggering life-threatening diseases like stroke. While drug therapy is the current main treatment, its bleeding side effects are problematic. Researchers are exploring nondrug thrombolysis methods, and photothermal therapy (PTT) offers a noninvasive approach with its unique benefits. However, PTT is usually not potent enough for complete thrombus eradication due to its low targeting ability. Herein, a targeted theranostic agent (S-PPc@ZnDPA) based on a phosphorus phthalocyanine (S-PPc) molecule was modified with phospholipids to enhance water solubility and loaded with the targeting molecule Zn(II)-bis(dipicolylamine) (ZnDPA). S-PPc@ZnDPA is capable of generating photoacoustic signals under 1064 nm light irradiation and has an efficient photothermal conversion efficiency (59.4%), making it a potential NIR-II absorbing nanoagent for integrated thrombosis diagnosis and treatment, as demonstrated by in vitro and in vivo experiments.