Polymer incorporated magnetic nanoparticles: Applications for magnetoresponsive targeted drug delivery

Efficient release and the delivery of active substances are necessary for diverse medical applications including biosensors, biotechnology, and medical therapy. Meanwhile, drug delivery to special tissues or organs has been explored via various modes, especially magneto-responsive targeted drug delivery. Magneto-responsive nanoparticles (NPs), that could be manipulated spatiotemporally through an external magnetic field, have garnered attention as active materials for advanced drug delivery applications. In particular, assorted biocompatible polymeric shells, e.g., carbohydrate polymers, lignin, polyacids, dextran, etc. are often adorned on their surfaces to restrain the cytotoxicity of magnetic NPs in the human body. Thus, a timely overview of bio-catalytic reactions responsive to magnetic fields is beneficial for providing more valuable insights into these efforts. This article aims to review core-shell drug delivery systems based on the significant and most widely exploited magnetic NPs (i.e., Fe₃O₄ and CoFe₂O₄), their mechanisms of action, targeting, and controlled drug release aspects. The pivotal requirements and challenges faced in the applications of polymer-coated magnetic NPs for cancer treatment are also briefly discussed.