Cucurbit[6]uril-functionalized Fe3O4 magnetic nanoparticles for pH-responsive drug delivery

In the present work, a new type of pH-responsive drug delivery system was successfully designed that is based on Fe3O4 magnetic nanoparticles functionalized with cucurbit[6]uril by thiol-ene click reaction. Various characterization experiments, such as SEM, TEM, FT-IR, XRD, XPS, and VSM, were performed to research the microstructure, morphology, composition, and physicochemical property of the prepared materials in detail. Then, the prepared cucurbit[6]uril-functionalized Fe3O4 magnetic nanoparticles were used to research the loading efficiency, loading capacity, and release percentage of doxorubicin. In the meantime, the influence of sample volume, loading time, pH, temperature, sample concentration, and carrier dosage on the loading efficiency was assessed and in vitro drug release behavior of doxorubicin in phosphate buffer solution with different pH values (3.0, 5.5, and 7.4) was examined. The results demonstrated that the developed drug delivery system based on cucurbit[6]uril-functionalized Fe3O4 magnetic nanoparticles showed high loading efficiency and pH-responsive controlled release behavior.