Nanoparticles for Pancreatic Islet Imaging

While clinical islet transplantation is being investigated as a useful method to cure diabetes mellitus (DM), the outcome of this therapy remains imperfect. This is mainly due to early graft rejection of transplanted islets by the instant blood-mediated inflammatory reaction (IBMIR) or islet ischemia. Therefore, it is important to develop imaging tools for transplanted islets, so that real-time treatment can be used to protect the islets from host immune reactions if required. Recently, synthetic nanoparticles are emerging in the area of biomedical imaging. Innovative nanoparticle developments have significantly enhanced the versatility of different imaging modalities. Nanoparticles represent potential probes to monitor transplanted islets through magnetic resonance imaging (MRI), positron emission tomography (PET), and optical imaging. Nanoparticles can be delivered to transplanted islets by conjugation onto the cell membrane, intracellular delivery, cellular membrane receptor or transporter targeting. Visualizing the survival, function, and biodistribution of transplanted islets may suggest an appropriate treatment, which will enhance islet graft survival. This chapter focuses on recent advances and applications of various nanoparticle-based imaging techniques used in molecular imaging to monitor transplanted islets.