Synthesis of multifunctional bovine serum albumin microcapsules by the sonochemical method for targeted drug delivery and controlled drug release.

Multifunctional folic acid conjugated BSA@Fe3O4 microcapsules (FA-BSA@Fe3O4 MCs) have been prepared successfully based on the sonochemical method. The as-synthesized FA-BSA@Fe3O4 MCs have a suitable size range for biomedical applications, and a high loading capacity for water-insoluble drugs. Furthermore, FA-BSA@Fe3O4 MCs show excellent magnetic properties. Cytotoxicity tests indicate that FA-BSA@Fe3O4 MCs are non-toxic. Cellular uptake and flow cytometric assay illustrate together that FA-BSA@Fe3O4 MCs can target tumor cells selectively through molecular targeted endocytosis. As carriers for water-insoluble drugs, FA-BSA@Fe3O4 MCs are also proved to possess superior redox- and thermo- dual responsiveness for controlled drug release.