Theranostic Nanoagents
Jason McCarthy, PhD

The combination of diagnostic and therapeutic entities into one drug delivery vehicle yields agents that are capable of the simultaneous diagnosis and treatment of disease. These ""theranostic"" agents have unique applications, as they not only promote the diagnosis and therapy of disease, but allow for feedback mechanisms to determine the localization, release, and therapeutic efficacy of treatments. Theranostic nanoagents further allow for the incorporation of multiple functionalities within one particle. These agents modify the pharmacokinetics of the incorporated moieties, allowing for the creation of drug release systems based upon the local environment or material composition. Finally, theranostic agents allow for detailed studies of the biodistribution of therapeutics in vivo using numerous imaging modalities.

In this image, the localization of a theranostic nanoagent comprised of a crosslinked dextran coated iron oxide nanoparticle, a near-infrared light activated photosensitizer, and a fluorophore is observed within an atherosclerotic lesion by intravital fluorescence microscopy. The agent uptake (red) is clearly visible within the carotid artery (blue, fluorescein angiogram) of an apolipoprotein E deficient mouse. After imaging, the lesion is irradiated with a 650 nm laser in order to induce the therapeutic effect of the photosensitizer.