CHAPTER 2:Image-guided Drug Delivery Systems Based on NIR-absorbing Nanocarriers for Photothermal-chemotherapy of Cancer

In recent years, great efforts have been given to researching multifunctional nanoagents that combine diagnostic and therapeutic functions for highly efficient and low toxicity antitumor treatments. In particular, combining real-time imaging with spatially precise photothermal therapy mediated by nanoparticles responsive to near-infrared (NIR, λ = 700–1100 nm) light through conversion of photo energy into heat has attracted interest due to its simplicity, safety and noninvasiveness, as well as targeting and remote-control properties. Apart from being directly utilized for image guided photothermal ablation of cancer, the photothermal effect of NIR-absorbing organic nanomaterials has also been exploited for remotely controlled drug release. This photothermal-controlled drug delivery system provides promising approaches to reverse multidrug resistance, for which the poor cellular uptake and insufficient intracellular drug release remain the rate-limiting steps for reaching the drug concentration level within the therapeutic window. In this chapter, we will systematically discuss the latest progress in the development of organic and inorganic nanocarriers used as a photothermal-controlled drug delivery system for the combined photo-chemotherapy of cancer. Various types of NIR-absorbing nanocarriers developed for the delivery of drugs, as well as image-guided combined photothermal-chemotherapies, will be reviewed. The final section will address the future prospects and challenges in this rapidly growing field.