Magnetic capture of superparamagnetic nanoparticles in a constant pressure microcapillary flow

Superparamagnetic nanoparticles were synthesised and their in-flow magnetic capture behaviour studied within transparent plastic microcapillary arrays (MicroCapillary Film or MCF). This system represents an in vitro analogue of capillary vasculature and facilitates easy optical observation of capture phenomenon. A dispersion of nanoparticles was delivered at a constant pressure to an array of capillaries sited adjacent to a 0.5 T permanent magnet. The spatial position of trapped nanoparticles relative to the position of the magnet was analysed. The position of nanoparticle capture appears to be dependent on both spatial location and fluid flow rate and suggests two zones in the magnetic field in which nanoparticles are acted upon differently; a ‘steering’ zone and a ‘capture’ zone.