Magnetic drilling enhances intra-nasal transport of particles into rodent brain

Getting drugs deep into the brain to treat cancers, neurological disease, and behavioral disorders is challenging. In this work, we tried to improve the efficiency of intra-nasal transport into the brain via the cribriform plate using magnetic particles. We and others have used magnetic particles for delivering heat, drugs, and genes. We performed experiments with mouse cadavers that received 250-nm-wide intra-nasal magnetic rods intra-nasally under different combinations of magnetic fields. We found that the application of helical dynamic gradients to the particles (i.e., both rotational and linear) improved transport from the nose into the brain, as compared to linear magnetic gradients alone. On histological examination, no tracks were observed to suggest significant damage to the brain during the transport process. We are currently building a system for testing with live animals, with eventual proposed application to humans.