Coated plant virus imaging agents
An imaging nanoparticle comprising a plant virus particle having an interior surface and an exterior surface, an imaging agent that is linked to the interior and/or exterior surface, and a layer of biocompatible mineral such as silica coated over the exterior surface, is described. The imaging nanoparticle can be used in method of generating an image of a tissue region of a subject, by administering to the subject a diagnostically effective amount of an imaging nanoparticle and generating an image of the tissue region of the subject to which the imaging nanoparticle has been distributed.
1. An imaging nanoparticle, comprising a tobacco mosaic virus particle having an interior surface and an exterior surface, a gadolinium imaging agent that is linked to the interior surface, and a layer of silica over the exterior surface, wherein the virus has a relaxivity of greater than about 25,000 mM −1 S −1 per particle.
2. The imaging nanoparticle of claim 1 , wherein a targeting moiety is linked to the exterior surface of the virus particle.
3. The imaging nanoparticle of claim 2 , wherein the targeting moiety binds specifically to an immune cell.
4. The imaging nanoparticle of claim 1 , wherein at least about 500 imaging agent molecules are linked to the virus particle.
5. A method of generating an image of a tissue region of a subject, by administering to the subject a diagnostically effective amount of an imaging nanoparticle, comprising a tobacco mosaic virus particle having an interior surface and an exterior surface, gadolinium imaging agent that is linked to the interior surface, and a layer of silica over the exterior surface, and generating an image of the tissue region of the subject to which the imaging nanoparticle has been distributed, wherein the virus has a relaxivity of greater than about 25,000 mM −1 S −1 per particle.
6. The method of claim 5 , wherein the method of generating an image is magnetic resonance imaging.
7. The method of claim 5 , wherein the imaging nanoparticle further comprises a targeting moiety is linked to the exterior surface of the virus particle.
8. The method of claim 7 , wherein the targeting moiety specifically binds to an immune cell.
9. The method of claim 5 , wherein the tissue region includes a blood vessel.