Development of multifunctional folate-poly(ethylene glycol)-chitosan-coated Fe3O4 nanoparticles for biomedical applications

The efficacy of magnetic nanoparticles (MNPs) for biomedical applications depends on the specic targeting capacity, blood circulation time and magnetic susceptibility. Functionalized chitosan-coated Fe3O4 nanoparticles (CS-coated Fe3O4 NPs) were synthesized by a non-solvent-aided coacervation procedure followed by a chemical crosslinking procedure. The surfaces of CS-coated Fe3O4 NPs were successfully functionalized with folate-poly(ethylene glycol)-COOH (FA-PEG) to obtain novel FA-PEG-CS-coated Fe3O4 NPs endowed with long blood circulation and specic targeting capacity. The as-synthesized NPs were characterized by dynamic light scattering, transmission electron microscope, X-ray diffraction, thermal gravimetric analysis, vibration sample magnetometer, Fourier transform infrared spectroscopy, and confocal laser scanning microscopy. As a result, the novel FA-PEG-CS-coated Fe3O4 NPs showed excellent biocompatibility, magnetic properties, good dispersibility, and proper hydrodynamic sizes in an aqueous medium. The specific targeting capacity of the as-synthesized NPs to cancer cells was also investigated. It was observed that the uptake of the FA-PEG-CS-coated Fe3O4 NPs by HeLa cells was significantly enhanced compared to the CS-coated Fe3O4 NPs and mPEG-CS-coated Fe3O4 NPs. These results clearly indicate that our novel FA-PEG-CS-coated Fe3O4 NPs with remarkable specific targeting capacity, long blood circulation, and superparamagnetism hold great promise for biomedical applications, including targeted drug delivery and hyperthermia therapy. [graphic not available: see fulltext]