"Increased Penetrance of Magnetic Nanoparticles through Utilization of an Alternating Magnetic Field for Purposes of Drug Delivery"

Magnetic nanoparticles (MNPs) have been shown to be very effective for the purposes of drug delivery, tissue repair, medical imaging and biosensing. However, the simple static magnetic field and gradients to concentrate the MNPs into the target site causes aggregation of the particles in only a few minutes, severely reducing the effectiveness of delivery and causing even smaller particles to aggregate quickly, preventing mechanisms of drug delivery in openings up to several micrometers in length. Considering that a pore size of several micrometers is already larger than our desired delivery point, changes need to be made to the magnetic field to reduce the aggregation. In this report, I detail the use of an alternating magnetic field and its ability to greatly reduce the degree of aggregation. Optimization of the process is presented through variation of magnetic rotation speed, with different speeds each showing some level of variation in the penetrance of the bare particles and polyethylene glycol (PEG) conjugated particles through a porous membrane mimicking the leaky vasculature properties of tumors.