Synthesis and Characterization of Gold-Shell Magnetic Nanowires for Theranostic Applications

Increasing interest has been given in recent years to alternative physical therapies for cancer, with a special focus on magneto-mechanical actuation of magnetic nanoparticles. The reported findings underline the need for highly biocompatible nanostructures, along with suitable mechanical and magnetic properties for different configurations of alternating magnetic fields. Here, we show how the biocompatibility of magnetic nanowires (MNWs), especially CoFe, can be increased by gold coating, which can be used both in cancer therapy and magnetic resonance imaging (MRI). This study provides a new approach in the field of theranostic applications, demonstrating the capabilities of core–shell nanowires to be used both to increase the cancer detection limit (as T2 contrast agents) and for its treatment (through magneto-mechanical actuation). The MNWs were electrodeposited in alumina templates, whereas the gold layer was electroless-plated by galvanic replacement. The gold-coated CoFe nanowires were biocompatible until they induced high cellular death to human osteosarcoma cells via magneto-mechanical actuation. These same MNWs displayed increased relaxivities (r1, r2). Our results show that the gold-coated CoFe nanowires turned out to be highly efficient in tumor cell destruction, and, at the same time, suitable for MRI applications.