Remote magnetic targeting of iron oxide nanoparticles for cardiovascular diagnosis and therapeutic drug delivery: where are we now?

Abstract

Magnetic resonance imaging (MRI) allows for an accurate assessment of both functional and structural cardiac parameters, and thereby appropriate diagnosis and validation of cardiovascular diseases. The diagnostic yield of cardiovascular MRI examinations is often increased by the use of contrast agents that are almost exclusively based on gadolinium compounds. Another clinically approved contrast medium is composed of superparamagnetic iron oxide nanoparticles (IONs). These particles may expand the field of contrast-enhanced cardiovascular MRI as recently shown in clinical studies focusing on acute myocardial infarction (AMI) and atherosclerosis. Furthermore, IONs open up new research opportunities such as remote magnetic drug targeting (MDT). The approach of MDT relies on the coupling of bioactive molecules and magnetic nanoparticles to form an injectable complex. This complex, in turn, can be attracted to and retained at a desired target inside the body with the help of applied magnetic fields. In comparison to common systemic drug applications, MDT techniques promise both higher concentrations at the target site and lower concentrations elsewhere in the body. Moreover, concurrent or subsequent MRI can be used for noninvasive monitoring of drug distribution and successful delivery to the desired organ in vivo. This review does not only illustrate the basic conceptual and biophysical principles of IONs, but also focuses on new research activities and achievements in the cardiovascular field, mainly in the management of AMI. Based on the presentation of successful MDT applications in preclinical models of AMI, novel approaches and the translational potential of MDT are discussed.

MRI-traceable theranostic nanoparticles for targeted cancer treatment

“…A better strategy would be to correlate biomarker expression to tumor grade of human samples. Magnetic targeting is another option, but very few clinical trials have been conducted - mainly due to lack of effective mechanisms for precise delivery of magnetic gradients required to navigate nanoparticles against blood flow (hydrodynamic drag forces in large vessels is significantly greater than magnetic forces) and to deep-seated tumors 23 , 198 . It is entirely possible that all the information needed to achieve optimal targeted therapy is in the literature and that we simply have not yet correlated all the necessary details to solve this complex problem.…”

Iron Oxide Nanoparticles in Regenerative Medicine and Tissue Engineering

“…By applying an external magnetic field, Shi et al achieved a slowdown of IONPs in blood flow, alteration of their trajectory, and ultimately efficient uptake into inflammatory cells, resulting in a clear visualization of plaques via MRI [203]. Similar to the magnetically enhanced plaque detection, drug-loaded IONPs can be directed and retained at the desired location by magnetic fields for theranostic approaches [204]. Magnetic drug targeting (MDT) thus realizes higher concentrations of bioactive molecules at the target site and mitigates potential systemic side effects.…”

Advances in Magnetic Nanoparticles Engineering for Biomedical Applications—A Review

“…Generally, tumor growth is accompanied by the development of a surrounding leaky vessel system and therefore, MNPs can diffuse and accumulate within the tumor tissue [181,182]. "Active targeting" relies on guiding and accumulating the MNPs (and drugs) using externally applied magnetic field gradients [183], sometimes assisted by surface functionalization of MNPs with biomarkers [129].…”