Magnetic Targeting of Therapeutics

Multiple formulations of nano-sized particles, capsules, dendrimers, lipids, ceramics and genetic materials are being investigated in multiple labs for delivery of therapeutic moieties to targeted tissues. Interest is driven by reducing health care costs while increasing therapeutic efficacy and cost of treatment. One technology, magnetic targeting, incorporates iron oxide nanoparticles, to target nanomedicine payloads, down the gradients of external magnetic fields. When iron oxide crystal domains are less than ∼20–40 nm, particles become superparamagnetic (SPION), that is exhibit no remanent induction but very high magnetic susceptibility in the presence of an external magnetic field. Thus, targeting can be vectored by magnetic lines of flux. Particles can be pulled out of the microcirculation and across membranes into tissues. Two target organs that can employ magnetic targeting are the heart (epicardium) and inner ear (cochlea).