Poly(4-Styrenesulfonic Acid- co -maleic Anhydride)-Coated NaGdF 4 :Yb,Tb,Nd Nanoparticles with Luminescence and Magnetic Properties for Imaging of Pancreatic Islets and β-Cells.

Novel Yb,Tb,Nd-doped GdF 3 and NaGdF 4 nanoparticles were synthesized by a coprecipitation method in ethylene glycol (EG) in the presence of the poly(4-styrenesulfonic acid- co -maleic anhydride) stabilizer. The particle size and morphology, crystal structure, and phase change were controlled by adjusting the PSSMA concentration and source of fluoride anions in the reaction. Doping of Yb 3+ , Tb 3+ , and Nd 3+ ions in the NaGdF 4 host nanoparticles induced luminescence under ultraviolet and near-infrared excitation and high relaxivity in magnetic resonance (MR) imaging (MRI). In vitro toxicity of the nanoparticles and their cellular uptake efficiency were determined in model rat pancreatic β-cells (INS-1E). As the NaGdF 4 :Yb,Tb,Nd@PSSMA-EG nanoparticles were non-toxic and possessed good luminescence and magnetic properties, they were applicable for in vitro optical and MRI of isolated pancreatic islets in phantoms. The superior contrast was achieved for in vivo T 2 *-weighted MR images of the islets transplanted under the kidney capsule to mice in preclinical trials.