Brain tumor targeting of magnetic nanoparticles for potential drug delivery: Effect of administration route and magnetic field topography

Abstract

Our previous studies demonstrated feasibility of magnetically-mediated retention of iron-oxide nanoparticles in brain tumors after intravascular administration. The purpose of this study was to elucidate strategies for further improvement of this promising approach. In particular, we explored administration of the nanoparticles via a non-occluded carotid artery as a way to increase the passive exposure of tumor vasculature to nanoparticles for subsequent magnetic entrapment. However, aggregation of nanoparticles in the afferent vasculature interfered with tumor targeting. The magnetic setup employed in our experiments was found to generate a relatively uniform magnetic flux density over a broad range, exposing the region of the afferent vasculature to high magnetic force. To overcome this problem, the magnetic setup was modified with a 9-mm diameter cylindrical NdFeB magnet to exhibit steeper magnetic field topography. Six-fold reduction of the magnetic force at the injection site, achieved with this modification, alleviated the aggregation problem under the conditions of intact carotid blood flow. Using this setup, carotid administration was found to present 1.8-fold increase in nanoparticle accumulation in glioma compared to the intravenous route at 350 mT. This increase was found to be in reasonable agreement with the theoretically estimated 1.9-fold advantage of carotid administration, Rd. The developed approach is expected to present an even greater advantage when applied to drug-loaded nanoparticles exhibiting higher values of Rd.

Curcumin-loaded magnetic nanoparticles for breast cancer therapeutics and imaging applications

“…26 However, efficiency of magnetic field-mediated cellular delivery of drug depends on the applied external magnetic field as well as the type of MNP carrier. 25,38,60,61 To determine the potential utility of the nanoformulations for possible magnetic targeting, MDA-MB-231 cancer cells treated with MNP-CUR were exposed to a neodymium external magnet for 3 hours. A detailed schematic representation of the experiment design is presented in Figure 8A.…”

Magnetic field enhanced convective diffusion of iron oxide nanoparticles in an osmotically disrupted cell culture model of the blood–brain barrier

“…36,37 These studies show a greater accumulation of the IONPs in the cortex near the magnet, with progressively lower accumulation in brain tissue farther from the magnetic field. Another group implanted tumor between 38,39 and demonstrated at least a five-fold increase in magnetic targeting efficiency compared to non-magnetic targeted ones. 40 Although this is the current state of the art, and has some limitations, it is not out of the question to consider the use of devices for generating "on/off" magnetic fields in discrete brain regions.…”

Water-soluble l-cysteine-coated FePt nanoparticles as dual MRI/CT imaging contrast agent for glioma

“…In brief, these cells were treated with FePt-Cys NPs at different concentrations (25,50,75, and 100 μg/mL Fe) and incubated for different times (24,48, and 72 hours). The control well contained culture medium without the FePt-Cys NPs.…”

“…Applications of these SPIONs range from the drug delivery system to MRI contrast agent and magnetothermal therapy for brain gliomas. [23][24][25][26] Thus, studying novel magnetic nanomaterials other than SPIONs for application in the diagnosis and therapy of brain gliomas is of great interest.…”