Multifunctional iron oxide/silk-fibroin (Fe3O4–SF) composite microspheres for the delivery of cancer therapeutics†
Abstract
In this article, we report novel multifunctional iron oxide/silk-fibroin (Fe3O4–SF) microspheres synthesized by simple salting out process. These microspheres are used as the carriers of doxorubicin hydrochloride (a traditional anti-cancer drug), denoted as DOX–Fe3O4–SF. The results show that the drug loading capacity (LC) is 3.3% and the drug encapsulation efficiency (EE) could reach up to 76%. The DOX-loaded microspheres exhibit sustained and pH-sensitive release patterns. The total DOX release is measured to be about 60% at pH 5.5. More interestingly, RhB-labelled Fe3O4–SF microspheres exhibit a striking endocytosis, selectively accumulating in the cytoplasm compared to the free RhB. The endocytosis of DOX–Fe3O4–SF microspheres results in only ∼10% survival ratio of HeLa cells after 48 h. Furthermore, because of the remarkable biocompatibility of SF, Fe3O4–SF microspheres show no cytotoxicity toward HeLa cells compared to DOX–Fe3O4–SF. The results clearly indicate that Fe3O4–SF microspheres hold significant potential for drug loading and delivery into cancer cells to induce cell death.