Electrospraying magnetic-fluorescent bifunctional Janus PLGA microspheres with dual rare earth ions fluorescent-labeling drugs

Magnetic-fluorescent bifunctional microspheres as a drug delivery system (DDS) possess magnetic targeting and fluorescent tracing capabilities simultaneously. The fluorescent intensity of DDS is weakened by magnetic particles, however; the fluorescent tracing of a drug cannot be achieved completely due to the separation of drug and fluorescent materials. In this study, we prepared a benzimidazole (Bim) fluorescent-labeling drug with dual rare earth (RE) ions as EuLa3(Bim)(12) to increase the accuracy of tracing and fluorescent intensity. The electrospraying method with dual parallel spinnerets was used to produce Janus polylactide-co-glycolide (PLGA) microspheres with Fe3O4 nanoparticles and the fluorescent-labeling drug EuLa3(Bim)(12) in separate chambers. Analysis results revealed that [PLGA/EuLa3(Bim)(12)]//[PLGA/Fe3O4] Janus microspheres simultaneously possessed superior magnetic and fluorescent properties. Moreover, the [PLGA/EuLa3(Bim)(12)]//[PLGA/Fe3O4] Janus microspheres showed higher fluorescent intensity than that of PLGA/EuLa3(Bim)(12)/Fe3O4 composite microspheres.