Construction of Magnetic Resonance Imaging Visible Polymeric Vector for Efficient Tumor Targeted siRNA Delivery

RNA interference (RNAi), known for the highly efficient targeted gene silencing, has been demonstrated to be a promising means for cancer treatment. Meanwhile, an effective approach for siRNA delivery is urgently needed to meet the needs for its clinical application. Herein, we constructed a polymeric vector labeled with superparamagnetic iron oxide (SPIO) for magnetic resonance imaging (MRI) visible siRNA delivery. EGFR antibody was also modified to the surface of nanodrug to enhance the delivery effect. Our results showed that the vector exhibited great siRNA complexation ability and mediated an increased endocytosis of siRNA without obvious cytotoxicity. Besides, both in vitro and in vivo studies evidenced the vector could effectively deliver siRNA into tumor cells, exert highly interfering effect, and show potent MR imaging capacity. The study provides a promising MRI-visible and EGFR targeting delivery system to improve RNAi efficacy for cancer therapy.