Integration of IR-808 and thiol-capped Au–Bi bimetallic nanoparticles for NIR light mediated photothermal/photodynamic therapy and imaging

Abstract

Near infrared (NIR) light detonated phototherapy for cancer treatment based on photothermal therapy (PTT) and photodynamic therapy (PDT) has attracted increasing attention owing to its deep tissue penetration. However, the low absorption ability and therapeutic efficiency of the photosensitive drug have restricted the development of phototherapy to a great degree. Herein, a kind of IR808 dye sensitized glutathione (GSH) cladded Au–Bi bimetallic nanoparticles (Au–Bi-GSH@IR808) was prepared to enhance the inhibition effect of tumors. In this nanoplatform, the construction of GSH cladded Au–Bi bimetallic nanoparticles can effectively generate ¹O₂ while exhibiting outstanding photothermal conversion efficiency (η = 34.2%) upon 808 nm laser irradiation. Furthermore, IR808 as a small molecule dye endows the Au–Bi-GSH@IR808 with a higher 808 nm light absorption ability and stronger photothermal and photodynamic effects. The IR808 sensitized Au–Bi bimetallic nanoparticles with a small size (5 nm), hydrophilia and dispersible nature, exhibit a noticeably enhanced therapeutic peculiarity. Additionally, the prominent CT imaging property of Au–Bi-GSH@IR808 means it is expected to be used as a CT imaging contrast agent in clinical applications. The results of the in vitro and in vivo experiments indicate that the synthesized nanoparticles have an excellent ablation effect on cancer cells, and they are expected to be widely used in the accurate diagnosis and treatment of cancer.