Magnetic core-shell nanoparticles

Thanks to the possibility to be manipulated by applying a remote magnetic field, magnetic nanoparticles (NPs) are among the most studied nanosystems for cutting-edge applications in medicine. Magnetic core-shell nanoparticles (MCNPs) are emerging as interesting materials in the biotechnology and material science fields, as they provide several advantages over conventional magnetic NPs, such as the possibility of coating highly magnetic but toxic cores into protective and/or biocompatible shells, and of engineering the shell surface to confer specific abilities. Cores and shells can be assembled to confer to MCNPs different shapes and designs for specific applications, as in the case of hollow core-shell and yolk-shell magnetic NPs, whose ability to encapsulate high loads of bioactive molecules can be maximally exploited for drug delivery purposes. After reviewing the composition of cores and shells, in this contribution we present an overview on MCNPs applications in hyperthermia, magnetic driving and controlled drug release, starting from well-established approaches to some of the latest and most innovative ones in the field of nanomedicine. In this respect, the use of materials such as mesoporous silica, graphite, and smart bioactive polymers enabled the production of highly engineered NPs with the ability to accomplish two or more biomedical functions. However, it is important to remark that the increase of functionality always entails the production of structurally complex MCNPs requiring long and difficult regulatory processes before entering clinical trials.