Remote Control of Gold-Iron Nanowires Using Low-Frequency 1 Hz Magneto-Mechanical Therapy and Cesium 137 0.662 MeV Radiotherapy for Treatment of Glioblastoma Multiforme.

Glioblastoma (GBM) is an extremely infiltrative brain cancer that is impossible to fully remove surgically and almost always recurs at the borders of the resection cavity. There is increasing focus on inducing cancer cell death using magneto-mechanical therapy (MMT), which involves energy conversion of an external low-frequency magnetic field into mechanical forces using magnetic nanoparticles. Here, we combined MMT with enhanced radiotherapy (RT)─the standard of care treatment for GBM─to increase the efficiency of treatment using gold-iron nanowires (AuFe NWs). The magnetic iron component of the nanowires mechanically rotates, inducing cellular damage, and the gold scatters X-rays due to its high atomic number, enhancing the local RT dose. We show that reproducible synthesis of AuFe NWs with different ratios of gold:iron can be achieved using a hard-template electrochemical method, controlling composition by tuning the deposition current. Ratios with best-performing iron percentages were selected for computational modeling to predict which frequency should be applied on a GBM cell line. testing, using a cell metabolism assay, and the optimal frequency and gold:iron ratio, demonstrated that applying MMT alongside RT resulted in a synergistic effect, reducing cell viability significantly by ∼60% (as compared with a 30% reduction for RT, with/without AuFe NWs), and a 20% reduction for MMT (with AuFe NWs). The increased efficacy of RT, post-MMT, was attributed to the higher association of the nanowires with the cells following application of the magnetic field and local membrane damage.