Drug Delivery Systems Controlled by Irradiation of Near Infrared Light

Gold nanoparticles have been becoming attractive metals in biomedical applications. The unique optical, chemical, and biological properties of gold nanoparticles have supported them for clinical interest in several applications including drug and gene delivery. Gold nanorods have strong absorption bands in the near-infrared region, in which light penetrates deeply into tissues. Hence, gold nanorods are expected to act not only as on-demand thermal converters for photothermal therapy but also as controllers of a drug-release system responding to irradiation by near-infrared light. These attributes can be promoted to provide an effective and selective platfalm for a targeted intracellular release of some substance. Here we review recent advances in the use of gold nanorods in drug and gene delivery systems.