As therapeutic tools, Magnetic Nanoparticles (MNPs) have been evaluated extensively for targeted delivery of pharmaceuticals through magnetic drug targeting (MDT) and by active targeting through the attachment of high affinity ligands. In the spirit of Ehrlich’s “Magic Bullet” , MNPs have the potential to overcome limitations associated with systemic distribution of conventional chemotherapies. With the ability to utilize magnetic attraction and/or specific targeting of disease biomarkers, MNPs offer an attractive means of remotely directing therapeutic agents specifically to a disease site, while simultaneously reducing dosage and the deleterious side effects associated with non-specific uptake of cytotoxic drugs by healthy tissue. Also referred to as magnetic targeted carriers (MTC), colloidal iron oxide particles in early clinical trials have demonstrated some degree of success with the technique and shown satisfactory toleration by patients. Although not yet capable of reaching levels of safety and efficacy for regulatory approval, pre-clinical studies indicated that some of the shortcomings of MDT technology, such as poor penetration depth and diffusion of the released drug from the disease site, can be overcome by improvements in MTC design. Furthermore, the use of MNP as carriers in multifunctional nanoplatforms as a means of real-time monitoring of drug delivery is an area of intense interest.

REF: Conroy Sun, Jerry S.H. Lee, Miqin Zhang, Magnetic nanoparticles in MR imaging and drug delivery, Advanced Drug Delivery Reviews,
Volume 60, Issue 11, 2008, Pages 1252-1265, ISSN 0169-409X,
https://doi.org/10.1016/j.addr.2008.03.018.