Manganese-based Polysilsesquioxane Nanoparticles as MRI Contrast Agents (2012)

Undergraduate: Honam Lau

Faculty Advisor: Wenbin Lin
Department: Chemistry

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Magnetic Resonance Imaging (MRI) is a powerful imaging technique widely used in clinical applications. It has the advantage that enables whole-organism anatomical imaging with a non-invasive approach. However, commonly used MRI contrast agents are molecules containing Gadolinium (III) that lack sensitivity and could be highly toxic, recently reported in diseases such as nephrogenic systemic fibrosis. In this project, we carried out the synthesis and characterization of a Mn-based nanoparticulate MRI contrast agent. Silsesquioxane molecules were used as building blocks to afford the desired Mn-based polysilsesquioxane (PSQ-Mn) nanoparticles. The synthesis of this PSQ-Mn building unit was carried out in a multistep procedure. PSQ-Mn nanoparticles were prepared using a microemulsion procedure and further functionalized with PEG chains to increase their biocompatibility. This material was characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and inductive coupling plasma mass spectrometry (ICP-MS). Some of the advantages of this platform over commercially available contrast agents are its large payload of active magnetic centers and low-toxicity. We envision that this novel material may provide a safer and more effective contrast enhancement for MR imaging.