In vivo targeted therapy of gastric tumors via the mechanical rotation of a flower-like Fe3O4@Au nanoprobe under an alternating magnetic field

Abstract

Owing to their hypotoxicity, great spatial resolution and tomographic properties, Fe3O4 nanoparticles (NPs) are becoming one of the most promising materials for noninvasive biological imaging and shape-dependent therapeutic agents for malignant tumor therapy. Conventional spherical NPs are unable to effectively destroy cellular structure in therapy and thus result in tumors with a high risk of drug resistance. Herein we developed a novel flower-like targeting Fe3O4@Au-HPG-Glc nanoprobe (thiol-containing hyperbranched polyglycerol (HPG); 4-aminophenyl β-D-glucopyranoside (Glc)) that can enhance magnetic resonance imaging (MRI) for cancer therapy. With the guidance of a targeting molecule, Fe3O4@Au-HPG-Glc nanoprobes can precisely target tumor cells. Under an alternating magnetic field (AMF), the flower-like Fe3O4@Au-HPG-Glc nanoprobes can rotate along the central axis of the core to substantially destroy tumor cells by damaging the nucleus or cell membrane. Our results showed that this shape-dependent therapeutic agent-based strategy had remarkable efficacy for MRI-guided tumor therapy. Furthermore, the inhibition of tumor growth in tumor-bearing mice was up to approximately 47.3% on the twelfth day of treatment compared with the level of inhibition in a blank group. Different from other reported methods for cancer therapy, our proposed AMF-dependent targeted cancer therapy is a novel strategy that can potentially reduce drug resistance in gastric tumors. Flower-shaped nanoparticles that can kill malignant cells in the body have been created by researchers in China and Australia. Iron-based nanoparticles injected into the body can attach to selected biological cells, but spherical particles do not adhere to the target cells for very long, limiting their usefulness. Now, Guo Gao from Shanghai Jiao Tong University and co-workers have realized improved magnetic resonance imaging and enhanced therapy of gastric tumors by adding gold atoms to the surfaces of iron oxide nanoparticles and using them as anchors for a many-branched polymer known as a hyperbranched polyglycerol. This polymer gave the nanostructures a flower-like appearance. By applying an alternating magnetic field, the researchers caused the nanoparticles to rotate. This rotation was used to destroy tumor cells in mice. Despite great efforts that have focused on anticancer adjuvants, drug resistance in cancer therapy is still a challenging problem. Conventional spherical nanoprobes are unable to effectively destroy the cellular structure in therapy which means the gastric tumor has a high risk of drug resistance. Herein we developed a novel flower-like targeting Fe3O4@Au-HPG-Glc nanoprobe that can rotate along the central axis of the core and substantially destroy the tumor cells by damaging the tumor cells under an alternating magnetic field. The successful application of novel shape-dependent therapy strategy would potentially reduce drug resistance problems of gastric tumors.