Magnetic Nanoparticles in Biological Applications

Dear Colleagues,

Developed in the 1960s initially for technological applications, stable suspensions of magnetic nanoparticles (MNPs) also called “ferrofluids”, emerged during the 1990s as building blocks for biological applications: Contrast agents for MRI, bio-assays using magnetic separation, internal heat sources for thermo-ablation of tumors, drug carriers with magnetic guiding capability or targeted drug release activated by an applied magnetic field, etc. The research on novel biocompatible MNPs is very active and multidisciplinary, as it involves chemistry for the development of the MNP core and of their coatings, but also physics for the study and optimization of their magnetic properties, pharmacology when dealing with conjugation to biological ligands, drug encapsulation, drug release, etc. From the materials point of view, the chemical composition and crystalline structure of MNP cores can be varied among several transition metals, metal alloys or metal oxides. However, most MNPs aimed to be in contact with living cells or organisms are made of magnetic iron oxides, in order to minimize the risks of toxicity that can arise with other metals (manganese, cobalt, nickel, zinc, etc.). Alternatively, mixed spinels or pristine metals can be used to optimize the magnetic moments. However, they need to be coated with biocompatible shells to avoid ion leashing, either organic or inorganic, as in the development of magnetic core-shells, or even magnetic tri-shells (e.g., ferromagnetic-antiferromagnetic junctions to create exchange bias effects). Other magnetic carriers or magnetic devices are hybrid, i.e., they combine an organic matrix and magnetic nanofillers, creating multi-functional or multimodal probes for bio-imaging. One can cite MNPs combined with liposomes, polymer micelles or vesicles, protein or mesoporous silica shells. In particular, thermosensitive matrixes (polymer chains or gels with a thermal transition, inorganic porous shells filled with wax as gate keepers, etc.) were proposed to tune the drug release kinetics by applied magnetic fields. This Special Issue focuses on all aspects of new nanomaterials using MNPs as active components for biological applications (bio-assays, diagnosis and/or imaging probes, drug delivery systems, etc.), or on the interaction of MNPs with biological media (biological fluids, cell cultures, or living organisms). Studies which shed light on the cellular uptake of MNPs and on the intra-cellular magnetic hyperthermia mechanisms are particularly welcome. Special attention will also be paid to contributions from talented early-stage researchers who are settling their original approaches or new directions in this field of research.

Dr. Olivier Sandre
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.