Authors: H. Kobayashi
Affilation: NCI/NIH, United States
Pages: 125 - 128
Keywords: nano-sized imaging agents, renal excretion, dendrimer, MRI
Nano-sized particles and molecules possess enormous potential as diagnostic imaging agents and hold promise for the development of multimodality agents with both imaging and therapeutic capabilities. Yet, some of the most promising nano-materials currently under investigation demonstrate prolonged tissue retention and contain heavy metals. This presents serious concerns for toxicity and additionally, prolonged particle retention may interfere with diagnostic imaging and testing modalities. The creation of nano-sized particles and molecules with optimal pharmacokinetics and clearance characteristics will minimize toxicity risks by reducing the duration of exposure to these agents. Given that many types of nano-materials possess easily modifiable surface chemistry, if nanoparticle characteristics associated with optimal pharmacokinetics and clearance from the body were well established, it would be feasible to design and create agents with more favorable clearance properties. In this talk, based on our experiences of dendrimer-based nano-sized MRI/Optical/Nuclear multimodality imaging agents, I will discuss the physiologic clearance of nano-sized particle and molecule, especially focusing on renal mechanisms, as well as provides an extended view of current research investigating clearance of other types of nano-sized particles and molecules, including dendrimers, quantum dots, and carbon, gold, and silica-based nanoparticles.