PEGylated nickel carbide nanocrystals as efficient near-infrared laser induced photothermal therapy for treatment of cancer cells in vivo

Photothermal therapy has attracted significant attention as a minimally invasive therapy methodology. In this work, we report PEGylated nickel carbide nanocrystals (Ni3C NCs) as an efficient photothermal agent for the first time. The nanoparticles exhibit a broad absorption from the visible to the near-infrared regions and a rapid rise in temperature when irradiated by an 808 nm laser even at a concentration of 100 mu g mL(-1). In vitro and in vivo cytotoxicity assays demonstrate they have good biocompatibility, which lays an important foundation for their biological application. In vitro studies reveal the efficient damage of cancer cells by the exposure of 808 nm laser with a power density of 0.50 W cm(-2). Furthermore, hematoxylin and eosin (H & E) and terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling (TUNEL) staining of tumor slices confirmed the obvious destruction of cancer cells in vivo by an 808 nm laser (0.50 W cm(-2)) after only a 5 min application. Our work may open up a new application domain for transition metal carbides for biomedicine.