Gold nanorods: Their potential for photothermal therapeutics and drug delivery, tempered by the complexity of their biological interactions

Gold nanorods have promising applications in the fields of drug delivery and photothermal therapy. These promises arise from the nanorods' unique optical and photothermal properties, the availability of synthetic protocols that can tune the size and shape of the particles, the ability to modify the surface and conjugate drugs/molecules to the nanorods, and the relative biocompatibility of gold nanorods. In this review, current progress in using gold nanorods as phototherapeutic agents and as drug delivery vehicles is summarized. Issues of dosage, toxicity and biological interactions at three levels (biological media alone; cells; whole organisms) are discussed, concluding with recommendations for future work in this area.