In vitro study of deep capture of paramagnetic particle for targeting therapeutics

Magnetic targeting, a promising therapeutic strategy for localizing systemically delivered drug to target tissue, is limited by magnetic attenuation. To satisfy the need of deep magnetic targeting, a special apparatus in which the magnetic flux density can be focused at a distance from the pole was designed. To test the aggregation property of this apparatus, we observed the accumulation of 500-nm paramagnetic particles as flowing through a tube served as a model of blood vessels. The relationship of the accumulation of the paramagnetic particles, the magnetic flux density, the magnetic field gradient and the fluid velocity was studied by theoretical considerations.