TiN nanoparticles: synthesis and application as near-infrared photothermal agents for cancer therapy

We have developed TiN nanoparticles (NPs) as a novel near-infrared-activated photothermal agent. The effect of nitridation temperature on the optical property and photothermal performance of the TiN NPs were investigated. The nanoparticles nitrided at 1000 °C presented a significant absorption along the whole biological spectral range (i.e., for wavelengths above 700 nm). After coated with polystyrene sulfonate (PSS) and poly(diallyldimethylammonium chloride) (PDDA), they exhibited well-defined spherical morphology with average size of ~ 50 nm. We also demonstrated their therapeutic efficacy against SW1990 pancreatic cancer cells. The results indicated that the PSS/PDDA-coated TiN NPs offered several advantages including high photothermal conversion efficiency (44.6%), high photothermal stability, broad spectral tunability, low cytotoxicity and facile synthesis process. These features make TiN NPs promising alternative for use as a photothermal agent in cancer photothermal treatment.