Authors: B. Chertok, A.E. David, V.C. Yang
Affilation: University of Michigan, United States
Pages: 8 - 11
Keywords: iron-oxide nanoparticles, brain tumors, magnetic targeting, magnetic field topography, intra-carotid administration
The purpose of this study was to elucidate strategies to enhance magnetically mediated accumulation of iron-oxide-based nanoparticles in brain tumors for potential localized delivery of chemotherapeutic agents. In particular, we evaluated administration of the nanoparticles via carotid artery using a catheterization method, not requiring vessel occlusion, as a clinically relevant local alternative to intravenous administration route. However, local administration exposes the neck and head vasculature to elevated concentrations of magnetic nanoparticles. The available electromagnets generate a relatively uniform field density decaying slowly over a broad range and leading to nanoparticle aggregation in the afferent vasculature of the neck. To overcome this problem, we designed a magnetic setup exhibiting sharper gradient and steeper decay of the flux density from the targeted region. Comparison of the two magnetic setups combined with either intracarotid or intravenous routes of administration was conducted in orthotopic 9L-glioma bearing rats. Analysis of nanoparticle accumulation in tumors revealed that with the basic magnetic setup, carotid administration failed to enhance tumor accumulation of nanoparticles compared to intravenous route. In contrast, the alternative magnetic setup resulted in a significant (p=0.018) increase in glioma accumulation of magnetic nanoparticles with carotid (42.7±7.4 nmol Fe/g tissue) versus intravenous (24.3±2.7 nmol Fe/g tissue) administration.