Sonochemical fabrication of dual-targeted redox-responsive smart microcarriers

In the present study, the molecular and magnetic dual-targeted redox-responsive folic acid-cysteine-Fe3O4 microcapsules (FA-Cys-Fe3O4 MCs) have been synthesized via the sonochemical technique, and targeting molecule (folic acid) and Fe3O4 magnetic nanoparticles are introduced into the microcapsule shells successfully. The obtained FA-Cys-Fe3O4 MCs show excellent magnetic responsive ability by the oriented motion under an external magnetic field. The hydrophobic fluorescent dye (Coumarin 6) is successfully loaded into the FA-Cys-Fe3O4 MCs, demonstrating that it could be also easily realized to encapsulate hydrophobic drugs into the FA-Cys-Fe3O4 MCs when the drugs are dispersed into the oil phase before sonication. Cellular uptake demonstrates that FA-Cys-Fe3O4 MCs could target selectively the cells via folate-receptor-mediated endocytosis. Moreover, the FA-Cys-Fe3O4 MCs show their potential ability to be an attractive carrier for drug controlled release owing to the redox responsiveness of the disulfide in the microcapsule shells.