Ultrasound and magnetism let drug-delivery nanobeads travel upstream

Although various groups are already working on nanoparticles that could be used for directed drug delivery via the bloodstream, most of those particles are designed to “go with the flow.” Now, however, Swiss researchers have created ones that can actually travel upstream.
Developed at the ETH Zurich research institute, the new nanoparticles are in fact tiny magnetic beads made of iron oxide combined with a polymer. They could conceivably also be loaded up with pharmaceuticals that had to be delivered to a specific location in the body. Each bead is just 3 micrometers wide.
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