(752h) Iodinated Nanoparticles for Diagnostic Medical Imaging Applications

Non-invasive medical imaging techniques such as X-ray-computed tomography (CT) and positron emission tomography (PET) are powerful tools in diagnostic medicine.  In these applications, contrast agents are needed to enhance the diagnostic quality of the images.  Ideally, contrast agents would be biocompatible and contain high payloads of contrast agent thus nanoparticle formulations of radiopaque or radioactive materials offer opportunities for improvements in diagnostic imaging.  In this work, we explore the use of Flash NanoPrecipitation (FNP) as a platform technology to produce such nanoparticle formulations of iodine (radiopaque) and its radioactive isotopes.  In FNP, amphiphilic block copolymers direct self-assembly of biocompatible nanoparticles with high concentrations of encapsulated components.  The precipitation process is controlled by carefully tuning the time scales of micromixing, self-assembly, and nucleation and growth.  Using this method, various routes to iodinated nanoparticles have been explored.  In one approach, an iodinated polymer can be encapsulated within the nanoparticles during the FNP process.  Alternatively, the FNP can be used to encapsulate polyphenolic compounds and the phenolic moieties within the nanoparticles can be iodinated.  Comparison using TEM and elemental analysis of these two approaches using sodium iodide with sodium hypochlorite as a model chemistry for iodination will be presented.   Radioiodination of various size nanoparticles (80 to 300 nm) for PET imaging applications will also be discussed.