Development of Magnetic-Fluorescent Bifunctional Drug Delivery System with Dual Drug Content and Enhanced Fluorescence

The drug delivery system incorporating magnetic particles and fluorescent marker would be uniquely effective for magnetic targeting and fluorescent tracing. In order for the fluorescent signals to reflect the drug delivery accurately, the separation of the fluorescent label and drugs must be counteracted. The objective of the current study was to design a method of binding drugs to the fluorescent material so that the drug diffusion and delivery could be monitored precisely. To obtain fluorescently-labeled drugs, complexes of the rare earth ion with a single drug benzimidazole (Tb(Bim)₃), and with combined drugs benzimidazole and aspirin (TbBim(Asp)₂) were generated. Subsequently, the magnetic nanoparticles Fe₃O₄ and TbBim(Asp)₂ were encapsulated in chitosan microspheres to prepare magnetic fluorescent bifunctional drug delivery system Fe₃O₄/TbBim(Asp)₂/Chitosan. The intermediate and final products were analyzed by spectroscopy, X-ray diffraction, magnetometry, and electron microscopy, documenting that the newly developed drug-containing nanoparticles exhibited desirable fluorescent, magnetic, and morphologic properties.