Drug Delivery System with Multiple Rare Earth Ions Fluorescent-Labeling Drugs and Magnetic Nanoparticles.

The bifunctional drug delivery system combining magnetic nanoparticles and fluorophore possesses the characterization of magnetism and fluorescence. However, the accurate tracing of the drug release and diffusion pathway is affected by the separation of drug and fluorescent molecule. In this paper, we synthesized the fluorescent-labeling drug by covalently binding Aspirin with rare earth ions Terbium (Te) and Gadolinium (Gd), which was incorporated into chitosan microspheres with magnetic nanoparticles Fe₃O₄ to prepare magnetic and fluorescent drug delivery system. Investigated by Fourier transform infrared spectrometer, fluorescence spectrophotometer, X-ray diffraction, vibrating sample magnetometer, and scanning electron microscopy, the chitosan microspheres showed excellent fluorescent and magnetic properties. Compared with the single rare earth ion complex, the multiple rare earth ions complexes with Aspirin Tb x Gd1- x (Aspirin)₃ · 2H₂O ( x 0.25, 0.5, 0.75) exhibited superior fluorescent intensity.