Multi-stimuli responsive smart chitosan-based microcapsules for targeted drug delivery and triggered drug release.

In the present study, we designed a novel, multi-stimuli responsive, biocompatible and non-immunogenic smart carrier for targeted delivery and triggered release of hydrophobic drugs. The designed multi-stimuli responsive smart chitosan-based microcapsules (MSRS-CS-MCs) have been fabricated successfully from folic acid (FA) functionalized thiolated chitosan via a facile sonochemical method. Targeting moiety FA and red fluorescent dye (Rhodamine B isothiocyanate, RITC) were immobilized onto the shells of microcapsules. Meanwhile, oleic acid (OA) modified Fe3O4 magnetic nanoparticles (OA-Fe3O4MNPs) and a model hydrophobic drug, green fluorescent dye (Coumarin 6, C6), were encapsulated into the microcapsules. As drug carriers, the obtained spherical MSRS-CS-MCs with the average size of 500nm showed excellent magnetic responsive ability, favorable selectively folate-receptor-mediated targeting functionality to the HeLa cells, and attractive reduction-responsive release ability for hydrophobic drugs. The integration of magnetic and reduction dual-responsiveness, folate-receptor-mediated targeting functionality and fluorescence visualization into the versatile microcapsules make MSRS-CS-MCs promising nanocarriers for future biomedical applications.