Poly(4-Styrenesulfonic Acid-co-maleic Anhydride)-Coated NaGdF4 :Yb,Tb,Nd Nanoparticles with Luminescence and Magnetic Properties for Imaging of Pancreatic Islets and beta-Cells

Novel Yb,Tb,Nd-doped GdF3 and NaGdF4 nanoparticles were synthesized by a coprecipitation method in ethylene glycol (EG) in the presence of the poly(4-styrenesullonic 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 Yb3+, Tb3+, and Nd3+ ions in the NaGdF4 host nanoparticles induced luminescence under ultraviolet and nearinfrared 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 beta-cells (INS-IE). As the NaGdF4 :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.