Magnetic targeting for site-specific drug delivery: applications and clinical potential

Background: Magnetic vehicles are very attractive for delivery of therapeutic agents as they can be targeted to specific locations in the body through the application of a magnetic field gradient. The magnetic localization of a therapeutic agent results in the concentration of the therapy at the target site consequently reducing or eliminating the systemic drug side effects. Objective: The aim of this review is to provide an update on the progress made in the development of the magnetic targeting technique addressing characteristics of the magnetic carriers and limitations of the current targeting magnet systems. Methods: This review discusses fundamental requirements for the optimal formulation of the magnetic carrier, current applications and potentially new approaches for the magnetically mediated, site-specific localization of therapeutic agents, including drugs, genes and cells. Results/conclusion: More efficient targeting magnetic systems in combination with prolonged circulation lifespan and carriers' surface recognition properties will improve the targeting efficiency of magnetic nanocarriers and enhance therapeutic agent availability at the molecular site of agent action. The main future magnetic targeting applications were categorized emphasizing the most promising directions and possible strategies for improving the magnetic targeting technique.